Hi new to the page so sorry if I post In the wrong place, I’ll get right into it. I was told by someone on a fb lt1 page that someone here by the name of “injuneer” was good at reading logs could help me but anyone with knowledge is appreciated, basically I was told my car is not running in closed loop and is compensating for something (looking at injectors) but has no cel lights while driving (only in on position) also has a constant pop only at idle but In drive it drove pretty well, I didn’t go wot as you’ll see in the logs to be safe rather than sorry although it kinda felt the car wasn’t as responsive (needs tune) I attached the log below. So for some details of the car: 94 TA, A4, longtubes, ypipe, egr/air delete, 255 racetronix pump, fuel pressure jumps to 45 and stays at about 43-44, new plugs and wires quadruple checked, and it’s stock for now other than that. I’ll take any info I can get as I can’t read logs other than basics and slowly learning about working on my own car. Here’s the logs from 94/95 scan, I can also email them thanks.
please let me know if this post should be moved elsewhere thanks.

 

That would be me. I'll take a look at the log. Sometimes a problem is obvious, sometimes it take time to find, and sometimes I can't find anything.


A quick look shows that it is going into closed loop exactly when it is supposed to - 206-second time from start, both O2's ready, minimum coolant temp met - in this case 129*F, a bit low). And it stays in closed loop for the rest of the log. And it correctly disables "learning" when you get aggressive on the throttle and put it into "power enrichment" mode.

Most likely looking at the long term and short term fuel trims. The thing that stands out at a quick glance is that when you go heavy enough on the throttle to put it into "power enrichment mode", the O2 sensor on the left side goes unbelievably lean, the right side not quite so lean, and the PCM is raising the short term fuel trims to prevent it from leaning out, and it's not helping. Looks like it's running out of fuel. Amazing that there is no knock retard.

Data log shows no codes.

Running lean would definitely cause the "car wasn't responsive" feel.


Under what conditions did you get those fuel pressure numbers? At idle? With or without the FPR vacuum compensation connected? Did you check the fuel pressure out on the road, under max load - WOT (or close to it) and at high RPM? What brand fuel pressure regulator, if not stock?

Who tuned it? Stock injectors? You may have deleted EGR, but the PCM is still trying to use it, so it hasn't been programmed out. What temp t'stat? Seems not to get very hot - after 6 minutes of operation, including driving under moderate load, coolant is still in the 170's.

I'll take more time to look at it, after you respond to the questions.

 

You’re the man thanks. Hopefully I replied correctly ha.

 

I just realized I have 5 different people I'm simultaneously trying to help (4 here, 1 on another LT1 site) with data logs at the same time. I'm going to move this to "LT1 Based Engine Tech", so all the data log requests on this site are in the same forum. Please be patient if I don't get back to you right away. These can be very time consuming.