G35X stalls when starting a warm engine

[mrfixit555]

I have a 2004 G35x. When I start a cold engine, it starts with no problem. If the engine is warm, it will stall if I try to restart after stopping somewhere. Giving it some gas when starting takes care of things, but something is clearly wrong. It looks like it is trying to idle at lower RPM with a warm engine vs. a cold engine. Any suggestions on a fix?

[joe603]

Odd...how many miles? any engine mods?

Try resetting the ECM (look at the G-series FAQ, link in my sig for the procedure).

[mrfixit555]

~150k. No engines modifications.

[mrfixit555]

I assume you mean the ECU reset procedure?

[johnparkyourcar]

Sounds like a vacuum leak. Try listening under the hood to find a hissing sound while the car is running. Could be a cracked hose or something. It's happened to me before.

[jho75]

I have a similar problem with my '04 G35X. The difference being that cold starts affect mine. It turns over and fires without any trouble, but idles rough enough that it stalls. The remote start tries three times but is unsuccessful. If I am in the car and give it a little gas while starting it sputters a bit but then runs fine after. When the engine is warm it isn't a problem. I quizzed a mechanic at work and he thought it might be the "idle sensor." I have noticed that the exhaust smells "rich" after these starts.

Thanks for any suggestions

[Dwass143]

did anyone actually get a fix for this issue.
I have a 2003 g35 coupe and it just started the same issue. it starts fine while cold but when warmed up after a restart the idle sometime drops so low the car dies, sometimes is corrects itself and doesn't die but the idle is still lower then I remember.
Thanks

[tollboothwilley]

get some CRC MAF cleaner. Clean off that 150K mile dirty MAF.

If that doesn't solve it cleaning the throttle body is the next possible culprit.. Be careful when cleaning as some people have had issues with ruining their throttle body.

that should take care of it.
If not:
Vacuum leak OR Cam Phase sensor could be going bad.

[miataeric]

My fiancee just told me this morning that she's having this sort of issue sometimes with her (our) 04 sedan. Unfortunately, we live 800 miles apart, so it's a little hard for me to look at. She said it will start fine cold, but if the engine is warm, won't start. And it's only happening some of the time. No idle issues, so probably not a vacuum leak. She's got a pretty good head around cars, but this one is the most modern (electronics and computers) that either of us has had. I had an issue like this several years ago with an old Audi that turned out to be one of the cam sensors or something like that, just remember I had to change a sensor on the side of the block (German crap)....
Anywho, I'm not sure what benefit resetting the ECU presents. Could someone please enlighten me what this would accomplish.
She says she's gonna take it someplace to get it looked at tomorrow, but her "local" dealership (2 hrs away) told her when she called that they think it's because I put RP oil in it =)).......Idiots! BTW the car only has about 70k on the clock.