Problem at Start-up

[floydr007]

Hey everyone, its been getting pretty cold here recently, and my 99' SOHC sport has been having an issue at start up. I'll start the car, and itll start just fine. The idle rises to about 1800, but then drops down to about 1000 and it starts running REALLY rough. Like so rough the car noticibly shakes. It sounds and feels almost like a Vtwin motorcycle lobing at idle. It will stall sometimes when this happens. This occurs only when it is cold out, and the car has been sitting. Once I put it into drive, the problem totally goes away, whether the engine has been running for 2 seconds or for minutes in park.. Once the engine has warmed up, the car will idle fine in park or neutral. I recently received the Bank 1&2 lean codes. I took it to a shop, they cleaned my mass airflow sensor and they searched for vacuum leaks using ether. They couldnt find anything and the problem seemed solved for a few weeks. I still have no codes. I got a new IAC last winter. I just cleaned it 2 days ago, and it hasnt had any impact. Have any of you had this problem? Do you think my IAC is going again? Any other opinions? Thanks a ton.

Also, I dont know if this is relevant to the problem, but when I'm driving under somewhat heavy throttle in top gear (5R55) i get a loud 'air pumping' noise from under the cabin. It sounds like just a ton of air whooshing through the exhaust pipe, maybe a leak or something? I dont hear it when the tranny kicks down, but that may be because the intake growls more then.

Once again, thanks for your help.

 

[gensic11]

Search for the 00m12 recall. It is covered under warranty up to 72,000 miles I believe and it replaces the O-Rings in the intake manifold gaskets. The 00m12 kit also comes with a new cam chain tensioner which may or may not even be an issue but if you have the stealership install the parts package you might as well have them install it if it hasn't been previously replaced.

There have been other threads about the 00m12 recall and also a write-up on how to do it yourself. Mikeh did an excellent write-up with step by step instructions. I wouldn't recommend doing it yourself, though, unless you knew what you were dealing with.