Will do that Saturday.

the LTFT'* should fluctuate based on engine load and what the PCM calcualtes to add or subtract fuel to make the car run based on what it wants

we will check FP, on your and my car this weekend

we also need to check Vac leaks

That was my thinking seeing the funky LTFT. Although if you're driving around with less than 1/2 a gallon, you're straining the fuel pump, and could really run into a lean condition if your tank got sloshing a lot.....

Yeah, after I posted I quickly remembered I was very low in fuel. I'm almost certain that'* why I was getting those ridiculous readings. Today the readings were "normal." I'll check my fuel pressure this weekend and see what I'm really looking at.

I'm almost certain I have a slow coolant leak which could cause some misfires that I've been having. I plan on doing my LIM gaskets ASAP, which will probably not be for another 2 - 3 weeks unfortunately. :?

You can't necessarily know for certain that a LTFT which moves frequently when not at WOT is caused by low fuel.

One of the things I've been doing since having a scanner/Aeroforce is to try and learn what the expected behavior of the various parameters should be at any given times. LT is one of those things that fluctuates. At least on stock pcms.

Currently my LT'* are anywhere from 0 to -13 since I changed some programming.

Yeah, it'* basically a guess right now as the only different variable was the very low fuel and I never saw such high (and low) readings until that point. Since they're back to where they were before, it just seems that could be the cause.

But 15.6 at idle just seemed really bad.

A question I posed earlier in this thread but wasn't answered (probably not a real easy answer) was how 'bad' is 6.2 for my LTFT at WOT? If I understand correctly, there is a certain point when the PCM can't compensate and adjust fuel. What is that point?

Was it +6.2 or -6.2? The LTFT value is reported in % so if you see +6.2 that means the PCM added 6.2% extra fuel while in PE mode, that means the PCM learned your fueling as being lean and needed to add fuel.

From the O2 value you mentioned (885), while it'* not necessarily accurate it has become 'known' to be a value that is too lean. If your LTFT value was in fact negative, meaning it was -6.2, then if correct that assuming your fuel trims locked at 0 while in PE mode, then your O2 value would have been in the 943 range which is thought to be safely rich.

Hope that helps.

Cheers,

My LTFT is at +6.2 at WOT which I understood was lean. And IIRC 10% is the point where the PCM cannot compensate anymore. :?:

Can you explain how you came to the number 943? What'* PE mode...drawing a blank. :? lol I need to know what PE mode is before I understand what you meant by a –6.2 LTFT and "fuel trims locked at 0 while in PE mode" means:

I thought I had read somewhere that the numbers were a percent, thanks for clarifying that!

Thanks!!

power enhancement, or performance if you like

When you have +LTFT that'* because the PCM is corecting for a lean condition, so yes you're correct.

The PCM can correct +16.4 and -22.6

Don't ask how I got the value, I'd have to shoot you after...

Oh...PE = Power Enrichment...otherwise known as the mode you should be in while under boost, unless you want fuel economy :?

Cheers,