Ever since i upgraded my fuel system with the 370 injectors and cartech FMU i always get code 45. Just wish i could drive my car without worrying about 45 always poping up. Its the code "system to lean/rich" Any suggestions? I know im running a little rich up top which evens out around 7000 so im guessing thats causing it. Plus my garage wall is BLACK! My N1 is letting out a lot of carbon. Thats the only real issue right now and i want to take car of it. Any ideas/suggestions welcomed, Thanks
Last edited by preludesh01201 : 08-31-2004 at 11:16 PM.
Code 45 is actually related to Short Term Fuel Trim and Long Term Fuel Trim, not running rich in open loop. If you are not pulling enough or pulling too much to compensate for your larger injectors, you could eventually end up with 45. 45 occurs when LTFT drifts too far out of the expected normal range. LTFT is figured from STFT. If you pull more or less than necessary for your large injectors, STFT will adjust to compensate, and in turn make a change in LTFT. So really this is related to closed loop operation and your VAFC settings for it. Whether you are pulling too much (too lean) or too little (too rich) could be determined by viewing your LTFT on an OBDII datalogger.
I would recommend resetting the ecu and then seeing if the code recurs before doing anything else.
Well im gonna go for a drive and see how much fuel pressure im running and ill let you know. We'll see how soon the CEL comes on at what fuel pressure.
Although that would be interesting, it's not going to tell you if you are too rich or too lean during closed loop. Also, like I said, this has nothing to do with rich or lean during boost.
hmmm, so what exactly should i do to figure this problem out. Dyno again? Also my exhaust is straight BLACK! Lots of carbon!! that mean anything, haha
Yeah. It means your O2 sensors and cat are going to die real soon.
Seriously, you need to get your fuel situation sorted out. Running that rich is very bad for the car. Not only does it kill O2 sensors and catalytic converters (both of which are relatively expensive), but it tends to wash down the cylinder walls with fuel. This is bad because it washes away oil, and your rings will start to wear really fast. This will show up as compression problems over the long run.
to put it simply, the car is attempting to compensate for an overly rich fuel setup during partial/light throttle application . it can't do it, because it's too far out of wack, so you get the code.
do you have a vafc? if so you can probably solve it by pulling some fuel across the board in the part throttle tables.
if you don't, you will need to address it by adjusting the fuel pressure. this can be a bit risky because it's also going to lean you out under full throttle/boost. if you drop your static pressure by, say, 10psi, you will want to increase your rise rate by 1psi or so. the only SAFE way to do this is on a dyno, and most dyno operators don't really know how to tune for good part throttle operation because of the nature of a dynojet.
i see. I do have a vafc so i guess its time to hit the dyno up again and fix that problem. My idle some times bounces too around 1200 to 600 rpms. It goes up and down and sounds like its gonna stall when i first turn the car on. I was guessing it was way to rich thats why.
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