I have a problem recently where on warm/ hot restarts, the car will hunt for its idle.

Climbs to 1800-2000, fuel cuts, drops down to 600ish, (?) Closed loop idle catches it and revs back up. When it drops down, "cranking" illuminates green even though its not. Starting the car from cold, it runs perfectly.

Attached is my tune and two logs, one shortly after starting and relatively cold. and fully warmed up after driving home.

Thanks for the help!

 

Turbo 1991 1.6. Flow force 640cc injectors.stock fuel pump. Forgot that stuff. But you'd see that in the tune.

 

Several long threads about this topic. Search both sections for hot start and MAT correction.

 

Figured it out. Though not through any threads on the forum, Over run fuel cut was cutting in because the temp was set so low. Raised the temp threshold to 160*. All is well now.

 

One thing i have found, is that your cranking RPM is set to 900!

 

Yeah, that seems super high to me too, but anything less than about 800 and I get starter kickback.

 

This can't be right, there must be something wrong with your cranking settings. Try using 0° cranking advance. Is your timing spot on?

If you set your cranking rpm that high and try to idle at say 850, your engine will always jump between cranking/running settings and this is why it's hunting and you see it in your logs.

When you are cold starting, warmup enrichment and your CL idle targets prevent this from happening, but the solution can't be to idle permanently above 1000rpm or so

 

I'll do that and report back.