'00 Grand Am surging upon starting

[Pontiac2000]

What is causing my 2000 Pontiac Grand Am GT with a 3.4 to surge and then die when it is first started? If you keep your foot on the gas pedal it will continue to surge for 30 seconds or more before it smooths out. Anyone else ever encountered this? Any thoughts? Thanks for any help this has been going on for while.


Sorry for the DB post fellas, I posted it first in the General Section with my intro. My apologies...

 

[melsg5]

How long since you performed basic maintenance, fuel filter, air filter, etc.? Have you cleaned your throttle body? Do you have a check engine light?

 

[Pontiac2000]

Pontiac2000

How long since you performed basic maintenance, fuel filter, air filter, etc.? Have you cleaned your throttle body? Do you have a check engine light?

Been about a year on the fuel filter, but car runs fine under hard accelleration and out on the highway now. It used to surge when out on the road, but I installed brand new air filter and Mass Airflow Sensor, and I have cleaned the butterfly on the throttle body. New spark plugs, ignition coils, and plug wires. The check engine light came on 2 times, and then went out on its own. The code showed an Mass Airflow Sensor and an Exhaust Oxygen Sensor code both times. When I replaced the Mass Airflow Sensor, it ran great for 2 days with no problems. Now it no longer surges when just driving down the road. It only surges for approximately 30 seconds when it is first started. I have to keep my foot on the gas pedal as it is starting, and for approx 30 seconds after starting, or car will die on down side of surges.

 

[melsg5]

There a two components you could look at, the Idle Air Control and the Throttle Position Sensor. Here is a write up on the IAC
http://www.automotiveforums.com/vbulletin/showthread.php?t=663849

and here is a video on the TPS

http://www.youtube.com/watch?v=Lve3zFg6-jk

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[msmith1956]

Another thing you could check is the EGR valve. I've seen them get some carbon build up and not always close properly and cause the same issue.

 

[Nate154]

You ever find the culprit to this or does anyone know? I have the same exact car that surges only upon start.

 

[CatSkinner]

If you followed the same maintenance procedures outlined here and your problem still persists, check for vacuum leaks.