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Need Help Please... Runs Lean For No Reason

Draconis

By Draconis,
in Engines & Forced Induction

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Draconis Enthusiast

Draconis

Posted
Posted

Okay, this has been going on for a couple weeks and during this time I havent figured anything out nor any pattern.

I'll be driving like normal... not boosting or anything. I guess you can say like 40 mph or something. Then all of a sudden it will run lean for no reason and of course there's a loss of power. It usually catches itself. Sometimes it takes a second or two but then back to normal. Worst case is that it loses all power so I pull into a parking lot, leave the car in neutral and it catches back to normal.

Here's what happened today. I was driving and down shifted to second, came to a rolling stop then started up again. As I started up from my rolling stop there was a bit of hesitation then it was ok. About 20 feet away it did the same thing... this time I pulled over and shifted to neutral but it died by the time I did this. I started up and everything was ok. I drove for about four blocks and the thing runs lean again. I step on the gas a little and it only does worse by making the car jerk. So as the car rolls, I drop the car to neutral and suddenly and my AEM Uego immediately swings to rich. I shift back to gear and it is fine then dies shortly after being too rich... I think it was too rich... I didnt catch the reading on the Uego for I was in traffic. It died so I just turned the key to off then started up the car and it was fine the rest of the way without issue.

I have changed out the O2 sensor a couple days ago. I changed the fuel filter in August.

I have a RB20DET with stock ecu. Plazmaman intake plenum, HKS SSQV Bov, Tomei 256/8.5 lift cams, top mount stainless steel exhaust mani, T3/T04e, Tial wastegate 38mm, FMIC, stock injectors, Splitfire coils packs, Greddy Type S boost controller (off) and a Neo (+4% on high boost at 6000rpm and up).

Any ideas? Like I said before, it doesnt happen all the time. I drove to work and there was no problem. The temp. when this happens varies... no rain or moisture coming down. I am confused.

Thanks.

R32_Matt Rising Star

R32_Matt

Posted
Posted

id probably look at getting bigger injectors and fuel pump with the retune as well.

as for the problem, afm, fuel pump and fuel filter are the first things that i would look at

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