Weird idle problem

[Rob]

I'm having a strange idle problem that I can't seem to figure out. Cold or hot start, it idles exactly where its supposed to. Coming to a stop or pushing the clutch in is fine also. What I'm having a problem with is driving the car and stop for gas, shut off the car. Fill up and restart the car, idles perfect. But the problem is moving away from the pump. As soon as I stop to pull out, it'll idle at 300-500rpm and slowly come back to where its supposed to be. I can do this same thing over and over and it'll do the same thing. After I drive, it'll idle perfectly again.

Why and what is causing this? Only after a drive and shut down/restart does it do this. It was doing this at the track also, especially after doing a burnout.

Any help would be greatly appreciated. I can post the hpt file if needed, on my laptop and not on this computer.

[Rob]

Here's the latest tune. Right now I have the idle spark the same as the main tables but I have done values of 28, 32, 36 and the same thing will happen.

[Russ K]

Scan the car using this idle config file. Do a cold start scan in neutral till operating temp, just let the car idle without touching the gas pedal or moving the car. Then copy the desired airflow histogram and paste it to the RAF table in the editor. List your mods as well.

Russ Kemp

[Rob]

I did that a long time ago but I'll do it again. I did modify my air intake setup recently but it was doing it with the old one also.

Mods:
GMPP LS6 heads, 228/232 cam, SLP Pulley, Dynatech LT's with cats, Yella Terra 1.7 rockers, Hybrid LPE/Speed Inc CAI, Bo White Ported TB, LS7 clutch, Corsa Touring Catback

[WS6FirebirdTA00]

if you can make it happen, it would make a lot more sense if you posted up a scan of it so we can have something to look at so we arent making blind guesses.

[Rob]

I did the idle config and changed the RAF. It's actually lower than stock. I put that in and did the two quick logs with it doing the low rpm swing. I then changed it back to stock RAF for the back half of the table and dropped the timing for surging. Mine seems to like less timing for the surging. I logged it on the way home and it did the dip when I first started and was fine when I got home 20 minutes later.

[Rob]

Still having this problem. Can't believe nobody has experienced this before. Hoping someone has the answer.

[WS6FirebirdTA00]

you need to tell us which log has what in it. The first one shows you have WAY too much idle airflow.

[WS6FirebirdTA00]

also, logging idle PIDs will help when you have idle issues. Log the throttle follower and cracker airflows.

[Russ K]

Still having this problem. Can't believe nobody has experienced this before. Hoping someone has the answer.

Try this tune, looks like you have the TB drilled as the RAF table is stock above 68*F, yet the LTIT & STIT are negative. Plug the hole & drill back to stock size. Why is your IFR table lower than stock? I also raised your idle speed & enabled closed loop at idle. I have a 229/242/.630 camshaft, and my car runs best in CL.

Scan your car with this Maf tune config file, just insert your wideband in place of my FJO in the table display.

Russ kemp

[Rob]

Thanks, I'll try that. The TB does have a hole drilled but from what I remember, so did the stock one. Its been awhile though so I may be mistaken. Couldn't tell you about the IFR. I don't remember changing it but it could have been done by the tuner before I started doing my own. Seems to not be a problem as LTFT are -2-+2 or so.

Don't have a wideband...yet

[Rob]

So far the car seems to be doing well with your tune. Haven't had a lot of time with it yet but the initial drive felt better. Hopefully I'll be able to get more seat time in it on the weekend to really see.

Russ, thanks again for the help.