Im trying to help a buddy out with a problem he is having with his car....

Situation

He had a new clutch put in, car ran fine afterwards... not sure why im telling you this, just want as much info out there as i can give. Its been a few months since then. A little while ago, about a month, he got a bad tank of gas.... and ever since then his car has been running like ***. He noticed his car was running bad about a 1/4 of the way thru the tank and put in a few gallons of 110 to help the mix out a bit....

Since then, if we try to get into boost, the car bucks like its hitting fuel cut or has a major boost leak. Ive checked his tune over several times, it looks normal... nothing flagged me as being wrong. Then i even posted his immobilizer over another flash i have that i know works and the same result. We've leak tested, the car holds 20 psi with no problems aside from the usual throttle body leak. There are no exhaust leaks. Current mods, invidia O2, invidia mani, hks rsi, forge mbc, tbe.... no fuel pump stock injectors.

Im posting his log i took during idling and i want to see what you guys think about a few things.... im looking at his O2 feedback being so crazy.... his AFRMAP that is usually 128 is actually changing and his fuel trims are off and he has the stock scaling and latency.

If you guys could post any ideas, maybe see something i missed. I am leaning towards a bad fuel pump or a clogged injector. But im hoping someone might know exactly what this is....

thanks

 

My guess is your guesses as well. Sounds to me like the pump could be crapping. Is it an VIII or a IX

 

I didn't see a link,

but couldn't he have some clogged injectors?

 

Yea the injectors being cloged up is also a possibility

 

sorry guys, i damn sure forgot to upload the log.... it is a lot of idling and then an attempt to do a pull.......

its uploaded now

 

any more ideas... or does everyone think i nailed it ?

 

well, he should buy a 255 then go from there.

BTW: whats up man?!!

 

Check the plugs or swap them with a set that it's known to work well. If the bad gas was contaminated with water one of the first things to fail are the spark plugs. Ask me how I know this

 

thanks...

forgot to mention,

we swapped plugs... he is running the same plugs i am, the denso ikh24's gapped to .024 for him. Thats what i originally thought as well aside from his tune being off because he was at first running the HKS RSI with no tune and he was running the famous upper ic pipe w/ ssqv that i made him take off and go back to stock bov.

 

Are you sure it is/was bad gas ?
When he add the 110 to the bad tank did that clear it up ?
Have you though about swiching MAF and ign coil's with a working set ? , might as well rule those two out b/c they are ez to change out .

 

You got it covered bro

 

i thought about that as well matt, i checked his MAF out, it is sparkling lol... we swapped to a new HKS filter with no luck. The car started pooping itself right after the gas so he is almost sure thats what it was.... after the racegas, i guess it didnt get any better... i didnt try swapping the coils out, but im pretty sure that isnt the problem. When we swapped plugs, we made sure it was seated properly and all the connections were good. Also, if it were coils, id think it would be idling a little rough. But aside from the fuel trims being off with stock injectors and scaling which i have never seen happen, its not sputtering... she idles solid. Im pretty sure its the pump, but i just wanted to ask the pool of geniuses on the site. If you look at the logs, you can see how screwy she looks.

 

I cant pull up the log on the work puter . "Bad" gas should not hurt the fuel pump , It would make the motor/knock sensor unhappy . Iam just not sold on the bad gas idea . The reason I asked about the coil's the might have enuf juice to fire at idle and low load but when the wick is truned up the they start to fail . I keep run this in my head and it just sounds like the fire isnt there.

Side note , try checking the fuel pressure . IIRC the psi spec's are in the manual..

Will this car be @ H&H tomorrow moring ?

 

i may be able to make him be there lol.... i dont know, you wanna look at it ? I can bring my stock fuel pump and you can swap it out for him if you want to rule out the FP.