2005 Chevy Equinox Low Power, Low Fuel Pressure Troubleshooting

hey guys skater Danner here got cameraman Caleb my son behind the scenes today I’m gonna be teaching to you guys and to my son let’s get started so the vehicle we’re working on today is a 2005 Chevy Equinox I don’t know a lot about it all I know or the symptoms and the customer states that he has low power and I don’t know if he checked his exhaust or thinks his exhaust is plugged or something like that the only thing I did so far was pulled a car from one side of the parking lot to the other and it hesitated very badly and here’s a shot of the codes I already did a code scan for us as you can see them right here on the screen we have a oxygen sensor heater circuit control on sensor one and on sensor 2 this is a 3.4 liter engine I believe they only use one upstream oxygen sensor on this so Caleb it uses all six cylinders would feed into a wide pipe and then they’d put a single OH – that would be for the whole engine rather than having bank one and a bank – so I think that the sensor – is downstream sensor one is upstream on this and then we have a lost communication with the anti-lock brake system when I start the car check out all these lights that are on it’s running like crap right now I need to see this see the ABS traction control light red brake lights on I’m missing a moment here that I shouldn’t be let me get to my data I shouldn’t have started it because one of the things I was thinking about when I see oxygen sensor faults is I want to see how the sensor reacts when it’s cold when I first started and I missed that window when we have a heater circuit fault I’m gonna shut this car back off yeah both trims are maxed out here Caleb well what I’m looking at right now is maxed out fuel trim and it’s actually getting better as it warms up here let me shut this off again zoom out on our data maybe I know so I missed a little window there on the initial start showing you guys the dash lights that are on but we should be okay in in still troubleshooting this and the reason I say that is I’m seeing some really bad fuel trim numbers here at idle 22% long-term and at one point I was at 25% on the short term so long term is pretty much maxed out that’s what that’s telling me and the reason I know that is my short term is also elevated so we have some some theory operation that would be needed to fully understand what I’m talking about with fuel trim and this is stuff that Caleb needs to brush up on he’s been watching my scanner dander premium lectures getting up to speed with stuff like this but my next step is I want to know what kind of lean condition I have in spite of the codes we’ll come back to the fault codes heater circuit faults somebody may have been playing around – I don’t know those could be history but what I want to know is do these fuel trim numbers get better or worse when I raise my rpm okay so just gonna do that wait let me get my RPM in here for you guys and there is only one upstream oxygen sensor – by the way there is not – so short term got better as the engine warmed up and what that’s telling me is this is a potential vacuum leak like an intake runner vacuum leak that’s not gonna give us low power though we’re gonna have to test drive this – let’s let’s see how this reacts I can hear coolant running through the heater core and the – as I raise the RPM that’s not a good symptom not a significant improvement at a higher rpm so I’m leaning away from vacuum leak now we have a lean condition and no longer thinking vacuum leak that test-drive this is going to be important I have an exhaust leak too that I hear which is not good it’s hesitating right there there there’s wide-open throttle zero I was holding the pedal to the floor alright so when I just said Aires wide-open throttle zero I’m talking about the o2 the upstream oxygen sensor

at frame 530 right here that I’m looking at right there is where I was at wide open throttle in fact let’s pull up the TPS you could see it to look frame 530 I’m at wide open throttle look at the o2 huff stream o2 is full lean while I’m at wide open throttle whoops this is a this is either a fuel pressure or mass airflow problem we’re starving for fuel it is what what this is that’s why he’s complaining about low power so I’m gonna do it again here’s wide open here the popping through the intake my foots on the floor right now that sound that’s a classic sound of a lean misfire and so a lean misfire the reason it will pop through the intake is that flame takes so long to burn with a lean condition a rich condition the flame front burns really fast a lean condition of burns really slow and it’s actually still burning during the valve overlap condition when we’re pushing the exhaust gasses out and we’re opening the intake valve for the next in rush there’s still a flame there and that’s why it backs up and pops through the intake popping because reignite its reigniting as it’s coming back in the cylinder before the compression stroke it’s burning the last event of the exhaust is still burning as the next ones coming in and it’s never really compressing it before the burn is occurring and it pops back up through the intake why is it still burning there’s a lean air fuel ratio burns really slow that’s what I thought so it’s so the flames still there it’s – it should have already burnt out and it’s not that’s the theory anyway I look I’m not a physicist and I’ve never seen this with my naked eye I’m only giving you my mechanic version of wild lean condition pops through the intake ok it’s the best I got ok you’re going to chemistry you’re learning chemistry this year pay attention to your what’s the nono there’s a term I’m thinking what it is thermodynamics laws of thermodynamics apply here I think if you see in that problem too okay physics anyway lean condition mass airflow fuel pump it seems like deja vu here there’s some quick tests we can do with the math that’s really what I want to focus on because we’re doing some skin data stuff and let’s see if we get a max on this map can you like test driving this is really gonna be stupid we need to I mean you can I mean what I was thinking is if we unplug the MAF and put in a default mode and rev it again like it is right now to see if it improves but I’m looking at my math numbers Kaleb and they look pretty good for what I’m seeing like 7500 Hertz is low but I can’t really rev it so we have honestly I want to put a fuel pressure gauge on this if there’s a service port that’s what we’re gonna do but I think it would be fun just to show you how crappy this drives let’s do it and you guys can watch the data as we’re driving too and we can actually know there’s a bunch of things we can do to identify this fault we have a bunch of cars to work on so I don’t know how crazy we want to get here but let’s just take this for a quick test drive I’m trying to move when I kid okay no it’s not the reason that the red brake light is on is because it has an anti-lock brakes fault okay that’s that’s as far as we’re going I can’t even move it okay I need to get it to the other I’m trying to get this to the other side of the parking lot right now I’m actually feathering the gas just so I can move because if I floor it well if you floor it then you have fuel pressure that’s even low or this is a fuel pressure problem this thing’s gonna need a pump come on I literally can’t even get up this hill so test driving this is not really happening I just need to get to the other side of the parking lot so we can set up our canopy and do what we

need to do all right so what do we as I’m trying to milk this car through this parking lot what do you do with the oxygen sensor heater codes that are in there and the answer is nothing they have zero to do with this problem so the heater circuit faults on the oxygen sensors to me is someone was probably in this car and was playing around and set those codes and we can address that maybe in some quick tests fuel pressure test is coming up next I just while I have you guys here and on the skin too I want to talk about my oxygen sensors here for a minute and those codes that we had what we’re gonna do is a quick test on these Oh twos and yet they’re full lean right now – just sitting here at idle in another observation if you look at the short term fuel trim we’re at zero so down here the short term trim at being at zero the car is an open-loop right now that’s why it’s sitting still I can show you the loop status even if the loop status contradicts what I just told you it doesn’t matter this thing when you see a short term trim that is not moving you’re in open loop and you can see that there’s a status now on the screen says open oxygen sensor on bank one is full lean upstream the downstream is also full een behind the cat I do not believe this is a mass airflow problem this being a three point four liter engine some theory or some suggestions would be a three point four liter engine should have roughly three point four grams per second of air flow entering the engine roughly and I have five point one six right now so there’s more air flow than maybe what I would anticipate for a three point four liter engine that being said what I’m getting at is this is not a mass airflow problem mass airflow is reporting at idle a number that would be higher than we would expect and so what that means is we should have more fuel not less so this link condition is not mass airflow related this is a fuel pressure problem in my opinion now why do we have the heater codes could very well be because this thing runs so lean that the heater circuit test the computer uses and I’d have to confirm that with a wiring diagram the heater circuit test the computer uses may be one where it’s using a bias voltage and it’s you start the car when it’s cold and what the computer wants to see with a working here is that that bias line voltage drop off and it should drop off very very quickly and when we see that that is an indication of heater circuit function activity the lean condition that this has may interfere with that and may may be setting false codes I don’t know the enable criteria of those heater circuit faults offhand but we’re not going in that direction I’m not putting oxygen sensors in this car someone could have been playing around too so a little bit of homework is needed there let’s attack the problem this has a lean condition and it is not an oxygen sensor problem okay a couple more thoughts on that how do you know Paul it’s not an oxygen sensor problem well did you hear how the car was popping through the intake you saw how the car would not rev at wide open throttle Caleb this is to you oxygen sensors are not used at wide open throttle so regardless of what the oxygen sensors reporting if I’m put white up and throttle the o2 is not even in play that’s because it’s a it’s full yeah we’re trying to rich in the mixture we’re not trying to trim it at wide open throttle so oxygen sensors not even in play okay so that’s you’re separating point in your mind that these codes are not related to this running problem is this running problem is there at wide open throttle cool cool so we’re not going that direction again we’re going fuel pressure and we’re going to pause it here and set up our canopy and get under the hood I could barely get hit here is that still rolling all right brand-new oxygen sensor that’s why we have heater coats yeah look at this mass airflow tube though I’ll have to look at that while I’m running the car if that’s closing up that could be an issue too but that just might be when someone put this somebody’s been playing that could be just when someone put the air box back on but this is a new oxygen sensor here’s your here’s your bank one let’s see if I can yeah you’re gonna have to get the camera here and I’m gonna get a

light so you can see it kind of tough to show you guys this shot but this is a brand new oxygen sensor back there so what’s that mean this means that someone is changing parts based off of fall coats my guests before these o2 heater codes showed up which I believe were customer induced is it probably had leaned the exhaust fault coats p0 171 which is a bank one system too lean and you know somebody through an o2 at it or it had Oh to low voltage codes somebody through an o2 at it fuel pressure that’s what we’re gonna check I am worried a little bit about this mass airflow tube but I think that is also induced by somebody else working on this that is an effect not a cause of what we’re dealing with here let’s do a pressure measurement nice and easy on this we have a service port love when they give us service ports Thank You GM that’s one that people use a lot they’ll see the fuel come out of there people will be like well I had fuel pressure so I’ll you know try to help people a lot and with questions and they’ll have low power complaint and I’ll say what’s your fuel pressure and they’ll use that and say well if you’ll squirt it out when I touch the service port what’s that mean it means nothing means nothing all right starting it who’s your daddy me 20 psi I don’t even know what the speck is on this car but it’s not 20 psi I know that so what I want you to see Caleb I’m gonna rev it I want you to watch this fuel pressure gauge I can’t rev it from under here because it’s a electronic throttle control so I can’t rev it up but I want you to tell me what that fuel pressure gauge does when I do a wide-open throttle it’s it’s gonna drop I’m pretty confident it’s dropping where’s it at it’s at a little below 20 like 18 that was wide open 17 now all right so what do you do let’s use this opportunity to talk about some variables and how I handle low pressure problems like this because our last video we did it was real quick when we did on a Chevy truck and a lot of you guys were right in that we could have had a fuel filter that was plugged up and I didn’t address that initially I didn’t address that here’s why the Chevy truck video which all reference in the description of this video so you guys can understand what I’m talking about those of you that find this video at a later date we did a Chevy truck fuel pump quick video again link will be provided a side note the way I’m doing these links now as I’m talking right now I’m mentioning this Chevy truck whatever the time frame is of this video I’m gonna put a list in this video that breaks down the topics covered or what’s what have we been titling it Caleb at the top video breakdown so I do video breakdowns by the minute maybe every few minutes I’ll give you kind of bullet points of what we’re talking about next so when you’re looking for a video reference previous video I will link that video in this time stamp I hope that makes sense that’s what I’m doing anyway the Chevy truck did not have a plug fuel filter here’s why we had about nine amps of current flow on that vehicle eight to 10 amps of current is normal current for that CPI system GM uses plugs filters cause higher than normal fuel pump current we did not have that we had an RPM issue on that pump we had normal current wasn’t a plug filter but that being assigned a lot of you were correct in the symptoms that I showed on that truck just like the symptoms on this car this could absolutely have a completely plugged fuel filter that is causing this condition and I have to tell you guys here’s how I handle plug fuel filters in the field how do you know how do you know if the filters plug the only way to know for sure is you would have to tee in a gauge before the filter and then compare the pressure after the filter okay so it involves extensive adapting of a fuel pressure gauge guys no one does this no one doesn’t it takes too much time if you think your fill filters

plugged at this point in the game change the fuel filter and retest it I’m okay with that but here’s why I don’t do it and I mentioned this in the comments of that last video I had a customer years ago when I worked for Pep Boys work truck comes in on the hook low pressure won’t drive won’t get out of its own weight just like this car ended up changing the fuel filter and the car ran great truck ran great customer was really happy because he only had to replace his fuel filter and he’s on his way got charged the diagnostic fee and a fuel filter that same truck came back to the shop two months later with a bad fuel pump and the customer actually was very angry at me as the technician because he had to miss another day of work so let’s talk about that scenario what happened a long period of time fuel filters don’t just plug up in one day they’re clear one day and plug the next day it’s a long gradual process of a filter plugging up that long gradual process to where the filter plugs so much that the pump is producing maximum pressure all the time just to try to keep up with the regulator setting is the system demand that pumps running full speed all the time full current full speed maybe not full speed full current right that pump massive amounts not massive amount sorry using wrong terminology here I’m just trying to emphasize the point that a plug filter will damage a fuel pump that fuel pump was on its way out so from that day forward when I get a vehicle with a plug filter I no longer even give my customers an option to change the fuel filter it’s getting a pump and a filter why because you get a plug filter you have pump damage and the car’s got 130,000 miles on it and it’s never had a fuel pump those are things to consider – okay I’m not saying there’s never a scenario where you can do a fuel filter alone we can have those issues but that’s why in the last video I never really even mentioned and it was my fault never really mentioned the fuel filter is being a concern this car has low pressure and I’m now down to about 16 pounds of pressure just sitting here at idle this matches all of our symptoms could have a plug filter we could have low voltage to the fuel pump we could have a bad ground I got videos on those two we’ll put some links in here one was a Ford Ranger with a faulty fuel pump ground that ran crappy when you turn the turn signal and headlights on pretty cool case study right bad ground the turn signals and the headlight circuits shared a ground path with the fuel pump that was the common denominator low power low pressure we can have that we have to check our wiring before we can confidently make a call and again as far as the fuel filter goes the only real test is replace the filter and recheck your pressures now we we have some modern-day equipment that we can we can kind of shortcut that a little bit in that at times I can do an amperage measurement and make that determination and that’s what we did on that chevy truck to the amperage was normal on pump telling us filter wasn’t plugged that’s what we’re gonna do this we’re gonna put a tool in an amp probe in series with the relay you get an amperage measurement of the pumps see what it’s doing right now and that will dictate our next step as far as do I need to crawl underneath and check my power and ground or not and Caleb this should sound familiar we have to check powers and grounds with low pressure before we can make the call okay that’s what we’re doing next so nice of GM to give us a diagram here our fuel pump is over here and that should be this relay right here so we’re gonna pop this relay out do some text right there the most awesome tool in the world this is it’s one of my favorite tools you guys that don’t know what this is and haven’t seen me use it before this is called a you activate tool you can find this tool on the tools page of my website help support a cause here and AES wave my partners in crime love my friends at AE s they sell all my paper books for me I bought my first Pico scope from AES wave in 2003 so we go way back before we had a working relationship alright this tool what I’ve done is I’ve removed the relay and what I’m gonna do is flip the switch and that should run my pump okay now in this case I can’t really make that determination because I can’t hear it let me bleed this pressure

off alright flipping the switch man is that slow alright so I am running the pump okay as you can see I want to in an amperage measurement right there now alright so switch is off I’m just clipping the amp clamp around this convenient little loop that’s given here as far as direction goes it doesn’t matter we can flip that around if it’s upside down I’m sitting on a 20 amp setting on the on the tool flipping the switch on guess what we’re not doing should have caught that I went guess what we’re not doing we are not crawling underneath this car to check tires and grounds I know caleb is super happy about that and so am I because I don’t want to lay on the gravel the grass isn’t bad what we’re looking at caleb is an average amperage here of about 7 amps of current flow so to have seven amps of current flow on a fuel pump on a system like this tells me this is not a power or ground problem it’s a fuel pump problem and you know the debate is still there on a plugged filter but we just had that discussion how do we handle plug filters how are you certain that it’s not how am i certain it’s not low power to the pump make something else so low low power so on average a fuel pump is it it’s hard to even give this spec anymore this is something that I teach but it has changed with today’s GDI systems and what they’re doing the fuel system so a wide variety of amperage changes with fuel pumps but I could probably give you a ballpark and say on average fuel pumps are going to run somewhere between 4 and 10 amps of current flow ok especially on this system I’m familiar with this system I don’t know what the pressure spec is offhand we can get that for you but this is right in the normal range of the fuel pump current for this vehicle ok so how I know I don’t have a power or ground problem was your question yeah a power problem that would make this thing run at 20 psi of pressure would be super low amperage here because resistance will as a voltage drop to the pump resistance causes a current drop to the pump we would have lower than normal amperage if anything I’m looking at on this system may be slightly higher than normal amperage okay I am certain this is not a power feed problem same thing with the ground the ground would be the same exact thing an elevated ground voltage let me give you this little lesson if my pumps feed is 12 and the pumps ground is zero that pump is running with 12 volts of potential that’s what we want okay if my pump feed is 12 and my pump ground is 6 the pump is running at 6 volts of capacity 6 volt difference in potential so that’s what a bad ground would do does that make sense an elevated ground so electricity flows with difference in potential okay there is there’s some ground theory stuff if that ground voltage is elevated to 6 volts and your feet is 12 it would be the same thing as the pump running with 6 volts feed so in other words pump ground is 0 pump feed is 6 would be the same reaction as a pump that’s running at 12 with a 6 volt ground difference in potential and that’d be half of what it should be so again ground issues here low current flow bad ground low current flow bad feed low current flow bad being high resistance okay our current flow if anything here is good if not a little bit high so now we can look at a little bit more in detail on this waveform and this could be one Caleb that I would say mount the camera right here have it set up on I just want you to yeah alright so what you’re looking at in here would be armatures of the pump and in the edits will pull in a picture of the commutator segments alright so this would be the front face of a fuel pump that you’re looking at you see here is a these are called commutator bars okay okay and this is where the brushes ride so you have a conductor and then in between the black line is an insulator conductor insulator conductor insulator conductor insulator okay all the way through and on most pumps are our eight bar so if you count them one two three four five six seven eight there are eight bars on this particular pump so one rotation we should have eight segments what you’re looking at with the amperes pattern here is when the amperage Rises it’s on a conductor when

the amperage Falls it’s on an insulator conductor insulator doctor insulator conductor insulator conductor okay yeah all right so we can calculate rotations of this pump which is what I want to do I’m gonna take a little bit longer of a time base we’re gonna go 20 milliseconds are you just looking for like a repeat yep like that actually what we can do let’s stay at 10 and then we’ll use the buffer freeze the picture zoom out this is the right way to use the snap-on scan tools as far as taking pictures this is probably that’s probably a real good one right there showing you repetition there’s right there and then there yes exactly so what you want to do we’ll pull two cursors in you want to pick a unique characteristic and to me the one that really sticks out would be that guy right there yeah and that was the one that you were putting that to and then put the same the other cursor on the same thing and then you can count yeah and then if we did this right we should have eight bars in here gm’s use eight bar pumps pretty much forever so starting at one my cursor one where that is that’s one two weird looking one three four five six seven eight back to one we did we did it right okay so we did our measurement and that is showing us one complete revolution yep okay so then you take that number and it is happening in 8.5 milliseconds so I’m down here my 8.5 milliseconds is one rotation to that pump okay okay so from here we need a little math you have your phone on you good we need it so um the math we’re gonna do is there are 1000 milliseconds in a second okay so that means there are 60,000 milliseconds in a minute yeah we’re trying to calculate revolutions per minute okay so 60,000 divided by 8.5 this will be the RPM of our pump it’s gonna be more than 6,000 thousand 7050 ate this pump is running at 7000 rpm 7000 rpm typical pump speed something that I’ve teach but is also variable I’d say 4 to 6,000 rpm is typical speed but we can’t really use that number and hold it with a lot of authority because my truck for example I did a measurement on and my trucks fuel pump runs at 9,000 rpm and it is completely normal sorry for the interruption I had to move my truck there we left off talking about my truck and the pump speed on my truck is about 9,000 rpm 9500 so there’s a wide range of speeds that fuel pumps run in and I think a 6000 rpm range is a pretty decent average for a you know port fuel injection type system so we’re right where we should be amperage wise we’re right where we should be speed wise the commutator segments of this you know there’s some inconsistencies in it but it’s nothing crazy I’ve seen a lot worse looking patterns with perfectly fine fuel pressure I would say that I’m not gonna analyze what exactly failed in the pump that’s not my purpose here my purpose here is to say we’re putting a fuel pump in this hands down no question about it and I’m not going underneath to check my powers and grounds I’m not worried about a plugged filter you know to each his own at this step you want to change the filter redo your checks go for it I’m not doing it okay this is getting a pump what’s some final thoughts let’s get you a fuel pressure spec one more time I’ll let you guys see this pump running and I’m hoping the tool helps us with this spec this would be the Vantage program of the snap-on tools that I’m using right now the snap-on advantage and I’m going after my fuel system fuel pressure yeah key on engine off 52 to 59 psi where are we yeah we’re at 16 all right we’re done it’s getting a pump some kind of impeller problem with this pumps I’m broken in in the in the tank so it would be nice to get some after readings of the new pump 1p puts it in puts this in I think maybe we’ll do that to finish this one up I hope we can do that we’re actually leaving for the beach I might miss the opportunity I might not be able to to show it unless he gets this done this week if he doesn’t get this done guys we’re done

we’re putting a fuel pump in this I’m hoping we can follow it up with the final amperage measurement just to show you what it would what it should look like pressure and amperage but I can’t promise you guys that I’ll do my best we should just do it I need I want to have it on this one I want to have it okay so this is getting a pump and what we’ll do for you guys to get a final wrap up of this we have to be four numbers and we’ll get some after numbers for you guys when Pete puts the pump and filter in this and then we’ll just wrap this thing up so stay tuned so while I’m cleaning up here I noticed something about this equinox we know this car this is the one that had no power to the injectors I have a video on this car and I repaired a wire right at the fuse box and this thing’s like broken and hanging here so the whole brackets broken but this is the wire I repaired and the reason I wanted to show you guys this is this heat shrink butt connector that I use to fix this wire split so some negative feedback on this style of heat shrink butt connectors that I was using and I I know which ones they are it’s not corroded it needs to be fixed again but either I overheated that butt connector and caused that split or these are just cheap heat shrink butt connectors and you shouldn’t use them so that’s a little warning here but this is a couple years old there’s no corrosion on this wire so you know a lesson on you know open contacts open wire poking holes and wires I mean this has been like this for a while and it’s not corroded it’s going to corrode eventually but that needs to be fixed again I’m just pointing this out this is a I’m not sure the date but I’m not a fan of this butt connector that I used for sure all right guys here is the after parts of this fuel pump video we actually had this vehicle towed from the tour’s Auto to Rosedale Technical College the owner didn’t have a lot of money and we offered to do the job for him for free of course the customer paid for the pump but we took care of the labor so it allowed us to get some footage of the after fuel pressure which is what we’re gonna look at here first and then we also confirmed power and we confirmed ground on the fuel pump itself different than what Caleb and I had done we were doing amperage and we said we didn’t need to check the power in ground but I had my students do that and then there was also a question with the split fuel tank split by the drive shaft so I’ve called it a split fuel tank a few times half of the tank is on one side of the drive shaft and the other half is on the other side and there are two sending units there are two floats on this system that was a little bit concerned about our checks and was there another separate pump that we had to worry about so we’re addressing those in here as well so here’s our fuel pressure reading watch this this is the after fuel pressure of new pump oh and by the way no fuel filter on this design is built into the pump there is no external fuel filter all right drew go ahead yep a little exhaust leak on this thing don’t we do a couple of stop royal tests again all right a note to you Caleb and to everyone else who’s watching watch this again I didn’t really like that pressure drop so you saw we were about 55 let me try to catch it so what is that number these individual yeah each one is one so that’s a 55 psi and let’s see what that drops to anarres again so it’s about 53 so it’s about a 2 psi drop on the wide open throttle snap I normally don’t like that Caleb and to the rest of you guys I’m talking to my son here he’s with me I don’t normally like the pressure drop like that at wide open throttle but this is a system that has a regulator in the tank in the tank and the regulators that are in the tank are a little bit slower to respond when you’re measuring rail

pressure so we’re measuring pressure at the fuel rail the regulators way in the back and this is pretty typical of this style of system that’s a mechanical returnless system with the pump in the back and that would be this is chapter 14 material just to compare the two this would be a system where the regulator’s up front right here okay we’re measuring here so the responsiveness of the regulator is very fast as opposed to this one where the regulators in the tank so when you have the injector spraying up front it has to react way back here you will get a pressure drop on some of these mechanical returnless systems there’s chapter 14 material so make sure you when you get a chance Caleb watch those lectures that’ll really bring you up to speed on what we’re talking about one of the concerns and what we saw was maybe we have a fuel filter that’s restricted not the case there is no fuel filter on the system it’s all inside of the tank it’s not a factor at all the only issue with this car is just simply that it is a mechanical return less system and the regulators in the tank this is not a problem again normally don’t want to see that perfectly fine with what we’re seeing there all right Caleb up next test-drive with my students we’re gonna revisit the wide open throttle Oh to test and then final wrap-up is gonna be the fuel pump current and rpm measurements of the new pump see what you guys don’t know is you’re now part of this YouTube video because there was actually a part one that I filmed with my son that we diagnosed this fuel pump is being bad and I had you guys retrace it so nice job on that and this is actually gonna be the end of this video we’re just gonna confirm on our test drive our are wide open throttle runs on our o2 and then yeah that’s pretty much it but that’s this is Bryce Thank You Bryce and drew nice job drew you guys did a really good job so I didn’t mean to be deceptive to you guys I needed us to learn I didn’t want you I didn’t want to tell you what it needed and I and I I to be honest with you I had some concerns on this system in the split tank and how it actually worked inside and to gather all those pictures was I think key for this whole diagnosis for me was knowing that there were no further texts that we needed to do what Caleb and I had called being the fuel pump as faulty was legit I had you guys do it differently I had you guys do power and ground checks mm-hmm we did current measurements from the front we never went underneath okay so when you guys get a chance when I put this all together make sure you watch this because I’m showing an alternative method of doing what you guys did okay what if you’re laying on the ground in a gravel driveway and you’ll want to crawl underneath and check tires and grounds I showed it another way and we confirmed it you guys confirmed it with your measurements so the power and ground measurements that you guys provided for me was perfect backup for what I did look at isn’t kind of a reinforcer that’s me every a reinforcement but onion would be one way but another message another tip nothing like option showed us with uh with a kiss like you can do a lot of different tests queen yes that uh that could actually reinforce like a voltmeter test as well yep so we want to look at you don’t have to focus on this true because the I have the screen recording guy okay you just you’re just cameraman for a minute all I’m gonna do all we need to do is wide open for auto low to run this thing’s a piece of yep it really is yep we do have a broken purge line alright that you’d point it out and that’s gonna make lien conditions but it’s not gonna affect our wide open from this thing had no power would not get out of its own way I’m trying to move when I kid and this is gonna be the key wide open throttle first year run watch your o2 rich the whole time see it yep so so just reiterating again low-power complaints use your o2 wide-open throttle it’s a good guy we used it to identify a fuel delivery problem there there’s wide open throttle

zero I was holding the pedal to the floor alright so when I just said air wide-open throttle zero I’m talking about the o2 the upstream oxygen sensor at frame 530 right here that I’m looking at right there is where I was at wide open throttle in fact let’s pull up the TPS you can see it to look frame 530 I’m at wide open throttle look at the o2 huff stream o2 is full lean while I’m at wide open throttle there’s other stuff you can look at mass airflow and volumetric efficiency testing that’s all involved too didn’t need to go that route it was as simple as the car wouldn’t run barely moved you know what give it up it was easy to check fuel pressure after looking at the o2 and rage the whole time on that wide-open is a fake so seriously special thanks to you guys for that all being involved here I think I think you really like the test and I I’ll show this to you guys personally next week when we get into the fuel delivery designs and systems where we can do amperage and current measurements right from the fuse box right from the relay I think I might have even shown it to you before but that’s that’ll be the plan next week so cool thank you thank you guys thank you just some real quick after readings of our fuel pump this is with the new pump car is running so we have you know more than battery voltage right about 14 volts I believe I had the car running last time I did this so we might have a variable in that if I did this key on engine oo will be at 12 volts as opposed to 14 volts so we’re gonna do this for both 12 volts and 14 so the the waveform itself what the way we’re set up 20 amps and we’re about a 10 amp average where we’re about a 6 amp average before and then I did a calculation for rpm I’ll show you guys how to do that pause the picture will zoom out a little bit and what we want to do is gonna be tough to see unique characteristics on a brand new pump actually I see one let’s go cursors show them and what I’m looking at would be that little one right there so kind of in the middle a little small ramp so we’ll go by that one and then it looks like maybe do you think it’s that same one right there you think count our humps 1 2 3 4 5 6 7 8 sweet it’s an 8 bar pump that one rotation of the commutator is um 8 bars 8 humps ok then what’d you do with that number let me break out your calculator we have eight point seven seven milliseconds between homes sorry for one rotation so 60,000 divided by eight point seven seven and we are at six thousand eight hundred and forty-one it’s funny because our before rpm was about 7,000 and our amperage is about six amps on this old pump and we’re only producing twenty pounds of pressure and now we’re at 54 psi at a little bit less rpm but higher amperage not that that really would help you going into it no anything like particularly it’s wrong with the pump but I still say it had some kind of impeller a problem with the pump itself some kind of pumping issue not electrically but something with the impeller cuz my amperage was much lower so that’s with the engine running and let’s get a shot of this now with just the engine off and of course engines off now we still have fuel pump current because we have this tool installed and we’re bypassing the computer bypassing the relay so my average amperage with the engine off is 9 amps of current as a comparison and I don’t remember what I did before so that’ll help me later so 9 amps of current go ahead start that again and you watch your amperage is gonna climb and the reason that amperage would go up is because charging system voltage went higher so we’re a ten point four average with it running I guess I should do a rpm measurement engine off turn the engine off so let’s see what that battery voltage dissipate for a second and then we’ll do a pause and zoom pull our cursors back in we’ll just put it between eight humps one two three four five six seven eight back to one would

be two there and we’re at ten point five three so do 60,000 divided by ten point five three okay cool and that is just make sure one two three four five six seven eight back to one yeah so are we dropped rpm about 1500 rpm less with higher amperage definitely some kind of impeller problem on that old pump