mugenhatchie

hello all. I am having a problem that I have never experienced before. I tuned my car and It has ran fine for over a year now. My problem is that as of last night my afr readings are leaning out. When I am cruising the afr's will slowly creep up to 17 sometime 20. Even when I add fuel it still starts to creep up. I don't think it is the sensor because the car does start bucking and you can tell it is losing power. WTF is going on?? I have tried everything and nothing has worked! Also at idle it will idle fine but then everyonce in a while it will lean out to 17/18 and then go back to 14.7. I have My LM-1 feeding my ecu a narrow band signal and I did a free air cal. to make sure, and the problem is still there. It only seems to do this once it is warmed up. I have gone through everything and can't figure it out at all. Also the second I shut off my car my afr goes to 20.9. Normally it would stay at what it was when I shut off the car and the slowly lean out (very slowly). I checked for an exhaust leak and I don't have one anywhere before the sensor. Any opinions would be extremely appreciated! BTW the car is a 94 civic cx with a built GSR tuned with crome free.

nekoabandoned

iTrader: (-1)

turbo, na?
it might be something like the fuel pump or motor dying on you.
my first motor in the old sol was doing that befor the motor blew, after switching the fuel pump and bottom end the sol ran like a champ till i sold it. btw i used the same ecu ( also chrome) and tune on the second motor, i had it like that for a long time befor selling it.

mugenhatchie

I know that the motor is good. BTW it's a 12:1 B18C1. Would a clogged fuel filter or bad pump cause this?? I am just curious because it only starts to do it after it warms up. I don't see how engine temp would have anything to do with a bad filter or pump. Just out of curoisity, if the wideband is going out would this cause the motor to go lean? I do have it wired into my ecu feeding it a narrowband signal (basically substituted for the stock NBO2). Still stumped ...

mugenhatchie

Alright, well it turns out that my transmission ground came loose. I noticed after my temp gauge started jumping (generally a sign of a loose ground). Sometimes the most obvious things are the causes. Hmmmmm well after a fried p72 and a loose ground....TIME TO NEPTUNE, YES!!!!!!!!