#97871, "Car runs lean under boost :(" Oct-21-06 08:31 PM by totaleclipse_05
Hey guys,
I've done pretty much everything I can think of, but my car still runs lean at anything above 4-5 psi. Once it leans out, it seems very slow on boost so I know something is wrong. I've searched and searched on this subject, but can't seem to pinpoint what it is. Here is what I have done:
-New Fuel Filter -Took off FMU and put on a friend's, but still leans out -Thought it could have been FCD's, but have tried 2 different kinds and still leans out -New O2 sensor
I just can't seem to figure out what it can be. I guess it could possibly be the fuel pump, but I don't know if that is a logical choice or not.
Please help me, I don't want to keep spending money on stuff that isn't the culprit.
EDIT: Guess I should let you know what I have. I have a Walbro 255 and Vortech FMU on stock injectors only running 6 psi tops, but I have lowered the wastegate down to 3 and it stays rich on that boost level. Anything above 4-5 though and it leans out and is very sluggish feeling.
Mike D -------------------------------------------------------------------------------------------------
Originally posted by DR1665 You're welcome to all the beer you can drink, but you have to go get it yourself. Don't get pissy when we point to the fridge and tell you to get it yourself.
#97874, "RE: Car runs lean under boost :(" In response to Reply # 0
OK, I just got done swapping fuel pumps with my friend's Walbro and it still does the same thing. So bad fuel pump is out. I have run out of ideas so if anyone has one, post up.
Mike D -------------------------------------------------------------------------------------------------
Originally posted by DR1665 You're welcome to all the beer you can drink, but you have to go get it yourself. Don't get pissy when we point to the fridge and tell you to get it yourself.
#97878, "RE: Car runs lean under boost :(" In response to Reply # 2
I knew the FCD wasnt the problem.
His FMU im guessing is probably a 12:1 and he is using a worthless nb02 a/f gauge.
You cannot trust those gauges, seriously. but if your sluggish then you have something f'd up, are you sure the FMU is hooked up right and you have the correct calibration kit in it?
My opinion first off would be to ditch the FMU and get a SFMU.
I even have an SFMU for sale for cheap in the F/S section.
#97881, "RE: Car runs lean under boost :(" In response to Reply # 3 Oct-23-06 05:10 AM by totaleclipse_05
I don't have any money to spend on more parts right now, I'm in debt to pay off what I have already. At WOT, those gauges *should* read in the rich part of it and it doesn't so that right there is a red flag for me. I read when I was searching that the ECU may pull timing when the A/F ratio gets too lean and that's what I may be feeling when I try to boost.
Yes, my FMU is hooked up right. It's by the fuel tank with the side port going to the FPR and the bottom port going to the tank. I've checked it all over and searched to see if it was right and it was.
For what I have and what I am doing, my parts should be ok. Yes, an SFMU would be safer to have, but I'm not looking for double digit boost levels right now. I'm just looking for a quicker daily driver. 6 psi or so should be ok for an FMU to handle.
Mike D -------------------------------------------------------------------------------------------------
Originally posted by DR1665 You're welcome to all the beer you can drink, but you have to go get it yourself. Don't get pissy when we point to the fridge and tell you to get it yourself.
#97884, "RE: Car runs lean under boost :(" In response to Reply # 5
Just replaced it a couple nights ago and didn't help the problem. I searched and came up with that as a possible culprit so I replaced it and nothing
Mike D -------------------------------------------------------------------------------------------------
Originally posted by DR1665 You're welcome to all the beer you can drink, but you have to go get it yourself. Don't get pissy when we point to the fridge and tell you to get it yourself.
#97887, "RE: Car runs lean under boost :(" In response to Reply # 7
I don't have one of those to tell if it is or not. Can you rent those at an auto store or do you have to buy it?
Mike D -------------------------------------------------------------------------------------------------
Originally posted by DR1665 You're welcome to all the beer you can drink, but you have to go get it yourself. Don't get pissy when we point to the fridge and tell you to get it yourself.
