: Stalling when raining.

06-12-12, 12:26 PM
Just curious if anyone has any ideas. If it is raining out it will idle poorly after startup. Even if it was just driven and is at operating temp.

I did have the car tuned. Small cam, pacesetter lts, hf cats, ls7 clutch.

I have no codes and no issues normally. I have also reset computer and clean my MAF regularly due to minor paranoia that my K&N is causing the problem.

06-12-12, 05:08 PM
Could this be strictly a tuning issue?

06-13-12, 02:01 PM
I'd check all the connections and grounds under the hood. Lots of places that water could be penetrating and messing with sensor values.

I rinsed out my engine bay and had one of the plugs on the underhood fuse box fill up with water. Car threw a couple codes and went into limp mode until I found it and dried it out.

07-04-12, 09:16 PM
The issue has now turned to a hunting idle upon start up no matter what the weather conditions are. A soon as it starts it hours right to 800 rpm then drops to about 500 them comes back up to almost 1000 then usually settles back to 800. It does this when I am driving through a parking lot as well. If I take out up to 3k in first then push clutch in to brake out cost out starts hunting again. On occasion it does stall.

I have checked connections, tried different gas stations, Cleaned the maf and throttle body, etc. there are no codes at all.

Can you clean / replace the motor portion of the tb? Would a code show if the ' idle air control motor' portion of the tb was bad?

07-04-12, 09:24 PM
About the only thing that cause erradic running with no codes is the ignition and the tune. When it is an ignition problem it usually shows up at high rpm as opposed to during idle. So my guess is that it is tune-related.

A problem with the throttle position sensor or the related functions should throw a code.

Vaccuum leaks throw codes more often than not, but such leaks can cause an erratic idle.

07-04-12, 10:19 PM
I did notice that the small vacuum hose on drivers side of tb was not clicked on all the way mostly likely causing a leak. However since I reclicked the line its gotten worse. Should I disconnect the battery? Has it learned how to idle with this leak and now it needs to relearn?

Also the tune was done almost 10k miles and 6 months ago. Wouldn't this have been a problem since day one. How is it getting progressively worse if it is a tune issue?

07-04-12, 10:49 PM
A tune issue should be present from day one unless something changes (new injectors, different MAF, etc.)

I would try the relearn process. I would test the ignition wires with a multimeter - they should no more than 1,400 ohms of resistance. And I would test each of injectors with a multimeter - they should a resistance value of 11-14 ohms.

07-04-12, 10:52 PM
Thanks darkman. I can always count on your knowledge whether its my thread or not.:D