Need help with idle/stalling

[Dale]

Its been atleast 4 years since I have tried tuning my car, or even messed with my efi live, so I've likely forgotten more then I learned from the beginning.... which was not much. More like enough to cause problems.

I have a TPI engine, running the ls1b pcm, os 12212156 (basically an L31 far as programing is concerned)

Since I have installed this I have always had idle issues. I've just lived with it for the past few years. Ive decided to try and fix it this year. Well, its gotten worse.

The original issue has been that whatever idle it is when it warms up from cold, becomes something completely different when its a restart warm and makes the engine basically stuck at fast idle. I think I may have gotten that issue fixed buy setting my b4307 in the middle at my warm engine temp range.

But now, when I gas the engine and let off, instant stall, no matter the engine temp. I have only changed B4307, raised b4522, raised b4521. Since the tune that I have had in it for all these years.

What would have changed that, as it never did it before.

[joecar]

Hi Dale,

Is your FPR manifold-referenced... If so, is the FPR ok (remove the reference hose and check for presence of gasoline which is not ok).

Post tune file and log files.

So is this engine the TPI 350 or TPI 305 ...? From which year...?

[Dale]

fuel pressure regulator. It does have a vac line going to it. It has worked fine for past 4 years, so I feel it is good but will check it tonight.

350 TPI. Its actually a crate motor with LT1 cam, 113 alumn vette heads, large runners. A hodge podge of mixed year parts. It has no cold start injector, no maf sensor. So wired up wise, about like a 91/92.

I can post tune n log files tonight as they are on a different computer.

[Dale]

0001 tune is the one I had in it for years.
0005 tune is current one in it that it stalls on
log 0009 is one testing tune 5. Sadly I don't show rpms on it, so its hard to know when it stalls out.

[Dale]

I think I just figured this out. The IAC was wide open, and a data log kept asking for tons more air. I looked at my throttle body and the set screw for the throttle stopper was about to fall out. Kept screwing it back in tell I could get It to idle. Guess it had come loose over all the years and the long term learn had slowly corrected for it.

[joecar]

OK, good to know, thanks for posting back.