fuel trims

[BurritaSVT]

Joey, you should have an email with my datalog shortly.

I am offshore at my work and the darn internet is downloading 15kbs very slow and you sent me a huge file so I will be downloading for a little while to view it but really it is better to view datalogs with the adaption off but this will work fine. Joey

 

[striker2]

Well the reason you are running fine is becaused th PCM corrected the problem by balancing the banks by adding or subtracting fuel but the real problem is not fixed but you are loosing power because the WOT is no longer monitored by the PCM in open loop so you can be leaving power on the table.

so in my case, there is actually a problem somewhere, its just still within the range of adjustment for the PCM so its not setting any codes yet.

I am offshore at my work and the darn internet is downloading 15kbs very slow and you sent me a huge file so I will be downloading for a little while to view it but really it is better to view datalogs with the adaption off but this will work fine. Joey

ok. take your time, whenever you can get to it is fine. i wasnt sure exactly what kind of driving you wanted so there is a lot there. the file is even compressed :crazy:

 

[BrApple]

ok I confirmed again that the short term trims are the same under load with the adaptive leaning turned off. pretty sure that was still under vacuum on my gauge also as I wasn't really getting on it.

what I felt as a slight miss between 2 and 3 krpm went away when I swapped my stock wires back on. I found that the Taylor wires will clip onto the plugs if the plug is in my hand and I really push on it. when the plugs are installed I can't get plug wires 5 and 6 to clip onto the plug firmly.

still need and will get to putting my wideband on each bank to datalog.

 

[BrApple]

I should also run a leak down test too shouldn't I?

 

[striker2]

depends on what the compression test shows. if you have any cylinders that are low, then yes, run the leak down test.

 

[BrApple]

depends on what the compression test shows. if you have any cylinders that are low, then yes, run the leak down test.

well the last time I ran a compression check I got ~140~145 across the board. this was on a cold engine with all of the plugs out. before I got a range between ~150 and ~180 on a cold engine with the plugs in.

also I did try out the leak down tester the other day. I got 20% on #4. I tried #5 and got ~50%. but I don't know if it was at tdc or not on that cyclinder.

 

[striker2]

140-145 is really low, even for a cold engine. hell, i was at 160-165 on the zetec with a cold engine and low compression pistons. 180 is much better, but you had the plugs in so i wouldnt call it accurate. i would run another compression test on a warm engine with no plugs in. post those numbers, and if any of them are low i would also run the leak down test. If i get a chance sunday i will probably run a compression test on mine as well.

 

[BrApple]

that is when I crank the engine 4 times per the instructions that I read. if I crank it until the needle stops climibing, on the few that I did that I it was all around 200, both times I did a compression test.

 

[BrApple]

I know the egr valve is suppose to be closed at idle but if it isn't or if there is a leak there how would that effect the fuel trims?

http://www.contour.org/ceg-vb/showthread.php?p=503889#post503889

I found with my hand scanner that the trims where about 0~1% and -3~4%. when I blocked off the egr the trims became -5~6% and -9~10%.

note this was not at operating temp but the pcm had gone closed loop.

 

[SicSE]

sfasdf

 

[BrApple]

I wouldn't sweat the specifics of HOW you do the compression test... just do all the cylinders the same. Personally, I pump to a max reading to help lessen the affects of variables like weather, battery charge, and the starting position of the piston in the cylinder being tested. It nets more consistent results and if there's a problem with a cylinder, you'll see it very clearly this way.

ok well when I did that previously, with plugs in and tight I got between 190 and 200.

so I am thinking that the engine is fine. but I suppose I could still have a leak somewhere.


anyway last night I set Joey data logs with my wideband installed in each bank so I will have to wait and see what he says and go from there.

 

[SicSE]

sdfasd

 

[striker2]

heres what Joey said to me regarding my datalog

the datalog shows that your bank 1 is running 10% richer this can be a few senarios you may have a low compression on one cylinder or you may have a weak spark or you may have a leaky injector. but yes you are running a little off on the banks for sure.

now, i have had a CEL for the precats (P0420) and i just checked it again yesturday and its also showing a P1519 (IMRC stuck closed bank 2 i believe). Now i know that IMRC works on both banks as i have reved it up at the throttle body and watched them both open, both when cold and when hot. I think thats just the sensor or wiring.

my thoughts. too much backpressure from a slightly melted CAT could allow exhaust gases to remain in the combustion chambers which would then act just like what SicSE is talking about with an EGR leak, causing it to run richer. This makes sense in my mind but i figured i would post it and gets your alls input on it.

BTW, stock monifolds with 94K miles on the car.

edit: a clogged/clogging CAT would also explain the lack of pull i think its missing in the upper RPMs, would have to drive another SVT that doesnt have issues to verify that though.

 

[BrApple]

hmmm, iirc bank 2 in my case is 20 % richer or it is trying to pull more fuel so the trim % is lower then bank 1.

I might have a miss but I am not sure. I do know when I have been logging and holding a constant rpm, without load I can sometime hear a poping sound from the exhaust. I know when I had two carbon tracked plugs/wires last year when it cut out under load it was very noticable in the tone of the exhaust.

so I do know that my compression varies alittle but I don't believe it enough to cause a problem. I tested the coil pack and the secondary coil resistance was out of spec, alittle high but not by much. The plug wires I put I took off because after a dyno it was suggested that the noise to it could be from poor ignition, and I wanted the Ford Racing Wires. The other set I was using was fine but I can't get #5 and 6 to clip on like the rest. and I could have some extra air getting in at or past the egr valve.

 

[99SEinLivonia]

Check the Intake gaskets..

Check the Intake gaskets..

Banks that far off... 2 likely reasons.

1. Intake leak
2. Exhaust leak

If one bank is drastically pulling fuel trim then a leaking injector could be the problem.

I've had the Cel come on due to air leaks between the LIM and head with crappy OEM gaskets. The carbon-tracking was ridiculous. Both banks on mine were out of limits lean though. New gaskets with RTV-blue for insurance fixed that problem.

If you've got one bank running lean due to leaks, might the other one run rich as the PCM tries to mitigate the lean side?

 

[SicSE]

asdfasd

 

[BrApple]

well what joey is telling me is that Bank 2 is running rich based on data logging with out a load having my wideband sensor in each bank.

I still need to verify that the headers are tight but I don't here an exhaust leak so I don't believe there is anything there.

Should I try swapping injectors from bank to bank?

As far as I know my wiring harness is in good shape.

Also I will again block off my EGR valve and see what the trims do once the car is warmed up. Yesterday I made sure the valve was tight to the UIM by adding a nut to the bolt the started to strip out. However I didn't see any change in the fuel trims when warmed up.

also as far as I know the wiring harness doens't have any issues.

 

[SicSE]

asdasdf

 

[BrApple]

This was withOUT the EGR blocked correct?

yes

I'm with you there. Even if there IS a leak, being inaudible, or barely noticeable, it would not let enough gas escape to mess up the reading from the O2. And with the pressure in the exhaust, it's damn-sure not letting any oxygen IN.

even at idle? if there was a leak it could draw in air at idle. off idle with boost pressure I doubt it would take air in, so maybe that is why the trims match off idle under load?

Seems like a long-shot given the circumstances, but it IS another thing you can eliminate relatively easily. That would rule out fuel and you've already ruled out spark. If it does the same thing after swapping the injectors, there could be no intelligent argument for anything other than a vacuum leak of some sort, (which includes EGR gas intrusion ).

well I keep seeing people saying stuck injector. Just thinking if that really is the case then swapping banks would swap the rich condition.

 

[SicSE]

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