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iTrader: (24)

Alright here is the issue. i was working with the RAF tables and of course that threw everything off as far as my AFR goes. no biggie gonna adjust the VE tables back to correct parameters.

I'm adjusting VE..... AFR numbers dont move. I adjust more, same thing. Alright that's kinda strange. I load up my stock tune to see if my AFR will move at least. Nothing. Whats going on?

I've tuned this car countless number of times and the VE table obviously would move my AFR around. I'm stumped. I've done all the steps to get the car into OLSD but it seems like the car is rejecting the tune. even the stock tune.

any and all help is greatly appreciated!

MontecarloDrag

iTrader: (3)

I had the same problem a few weeks ago, I couldn't change the AFR no matter what I tried. I changed tunes, modified VE table, tried another PCM, another WB, with no success.

Then I found the battery was dying and the car had ground issues. Fixed the grounds and put a new battery and I had AFR control back.

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iTrader: (24)

Alright I dont know why it works now but it's taking my commands now. What I did was manually turn off the fuel learn options via the scanner. I toggled them on and off a few times and after that it took my commands. I'm guessing electrical gremlin? Anyways it's working now

Thanks MontecarloDrag for the suggestion.

foff667

iTrader: (2)

VE has very little control over fueling unless the maf is failed.

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iTrader: (24)

Yeah all the steps were followed both from the How-to in the programs Help section and from other sources. all MIL codes were set accordingly. Like I said i toggled the fuel trim buttons a few time and then it started following my command. Iunno, it's working so i'm not messing with it haha

MontecarloDrag

iTrader: (3)

Good to hear you got it sorted.
Sometimes the PCM gets confused and does some funny things it's not supposed to.

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iTrader: (24)

alright this problem is at it again.

Monte, what all grounds and such did you mess with?

I dont know why but this car does this every once in a while and it's starting to become annoying

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iTrader: (24)

Alright well I disconnected the battery for a couple of hours, disconnected the PCM wiggled wires on the sensors and the damn car is still acting up. I'm leaving it outside in the rain, maybe she'll fix herself (unless the hail destroys her). The battery has a good charge on it as well.

Now I know if i disconnect the MAF/IAT sensor the commanded AFR will change since it goes to like -32 degrees. I did that a few times unplugging and plugging back in and the AFR does change accordingly. I have all the tables set correctly to fail the MAF on the start up.

Any ideas?

BLK02WS6

iTrader: (2)

Do a search for Corvette C5 grounds and you will find that there are about 4 or 5 grounds that you need to make sure are good - somewhere there is a diagram showing where they all are. They can lead to all kinds of PCM and sensor problems if they are not good. I learned this the hard way back in 2004 - had one that had intermittent problems with sensors and I could not figure it out for a long time...

ctd

iTrader: (1)

Did you zero out the MAF table? That has caught me more than once.

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iTrader: (24)

ctd, yes everything is in order.

that's what is stumping me, only thing i'll change is the VE little at a time and it will accept the changes. then once in a blue moon when i'm trying to correct another part of the VE table no matter what changes happen, it wont respond to them. all this is on the same file being updated as i upload it to the car.

BLK02 i'll try out the grounds issues. I checked them over a year ago and they were cleaned up, I was in Ca but since then am now in Dallas. so hopefully that is all that is wrong with it.

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iTrader: (24)

Alright did the grounds and all using this thread
http://forums.corvetteforum.com/c5-t...tion-long.html
nothing changed, the grounds had alittle bit of sand but nothing corrosive going on in there. any other ideas?

I flashed the stock file back in to see if it would fix it, but it's still doing the exact same thing.

now if it was having a leak some where and sucking in air the scanner should be able to show unmetered air getting in behind the MAF.

just thinking aloud here, maybe someone can think some thing else up?

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iTrader: (24)

and back, I think it IS leaking somewhere. I scanned it with the LTFT and STFT back in the stock tune and they are all maxed out.

now to play the hide and seek game with this air leak.

I'm spraying the engine with some carb cleaner to hear for a change in idle quality but ran out so i'm going to be getting some in a minute to try and figure this **** out.

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iTrader: (24)

another update, I checked the car over on the intake side with an unlit propane torch to see if the idle would rise and such. one of the gaskets was shot (actually all 8 were flat like Angelina Jolie's chest ) i'm like alright, this is the problem. i change them all out and go to turn on the car, it idles alittle better now but it is still maxing out the WB sensor on the lean side.

anyone have some idea?

mm_n_p

sounds to me like the wide band sensor may be shot

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iTrader: (24)

no sensor is working, when i command the AFR in HPT to say like 13:1 the WB will move accordingly then start leaning out again. the car shakes, sounds and smells lean with all the expected popping. I'm gonna buy a fog machine tomorrow and try to smoke the engine out. hopefully it's instant fix other wise i bought a 50 dollar tool for nothing haha

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iTrader: (24)

Alright well I just finished checking the seals with the fog machine and there are no leaking points. I went ahead and checked the vacuum with the gauge and it's holding a steady 18 inHg at idle. The needle is not flickering at all to indicate springs or seals screwing up.

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iTrader: (24)

and we are back. I checked the fuel pressure at the rail and am getting a rock hard 58psi. now I revved the engine alittle to about 2300 rpms and the engine sounds like as if you were rolling on and off of the throttle bringing the rpms up and down as well. almost as if it was a weak 2-step sound for lack of better illustrative words.

so recap.

18inHg at idle solid.
58psi at the rail solid.
no vacuum leaks anymore, verified with smoke machine/unlit propane torch.


any idea's?

danieloneil01

Get it fixed?

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iTrader: (24)

nope, parked it and continued working on the Camaro. I'll get back to it when I have more ideas