Starts and dies at cold start-up

[spacelucky17]

I've been fighting a several month long battle with this car and need some input. On cold start-ups it starts, runs for 5-10 seconds and dies. It takes several tries to get it to stay running, and when it does, the exhaust smells terrible. Codes read as MAF reading low- I have replaced it twice and even tried running with it unplugged, no difference. Then I replaced a vacuum line that was cracking, and cleaned the EGR valve, which helped for a month or so. Now that the outside temps took a dive, its back to the same issue, but when it sits in the hot sun all day it runs fine. And maybe the outside temp has nothing to do with it and its all in my head The next step seems to be replace the EGR valve, but I hate to spend a small fortune on a new one if that may not even be the cause, as I have thrown enough money in this pit. I've also read that the fuel pressure regulator can cause this issue. And taking it to another shop is definitely out of the question as they like to throw even more money in the pit, ("maybe we should try this" ummm no thanks). Thoughts? Suggestions? Any tips would be appreciated!

[soggytoast]

I'm in the same boat as you with a very similar problem. What I've been doing is tapping on the gas as soon as it catches, which brings the RPMs up high enough to get it to idle properly. Otherwise it just sputters out.

I have a post a couple of lines down. No idea what the cause is though.

[spacelucky17]

does yours first stutter when you step on the gas? Like there is a delay in it wanting to stay running?

[crash93ssei]

I would see if you can get it on a scanner and check what the intake air temp sensor is reading, also remove and clean the idle air control valve and it's passages as that can lead to poor idling especially when cold. Other then that double and triple check every inch of vacuum line for cracks or splits.

[soggytoast]

does yours first stutter when you step on the gas? Like there is a delay in it wanting to stay running?

Not when I step on it, but when I release it does. It will almost stall, then the RPMS shoot back up and then finally I get a steady idle.

[spacelucky17]

I cleaned the idle air control valve, lost the little ring thing off it though. Still running rough and trying to die at start-up, only now it idles erratically once it does decide to stay running. Guess I will replace the iac valve now! I've double and triple checked every apparent vacuum hose, are there some hidden in the front or back side that may not be so obvious that I'm missing? Thanks!

[crash93ssei]

There is a vacuum T fitting right under the supercharger snout that likes to crack, I fought hell with that one for a while on my SSEi, that would be worth looking at if you haven't found that one already.

As for the little ring thing around the IAC valve, that is just an O ring and could likely be the cause of the rough idle. Just go to the local parts store and find an O ring that fits it and still allows it to slide into the bore, much cheaper then replacing the IAC.

[spacelucky17]

I will look for that, And thanks for the tip I will look for the O-ring as well.

[spacelucky17]

Well I found the vacuum leak! Throttle body mounting gasket was the culprit. Everything cleaned up, gasket replaced, O-ring on the IAC valve replaced and.... it ran great for a few days. Now it wont hold a steady idle at all. In park in races between sputtering and dying to almost 2000 rpms. WTH?!