Bad idle on start up

[99GS_Turbo]

So I have a 99 GST. When I start my car up in the morning, the idle will jump to about 3k until the car heats up and then it hovers around 600rpm. If I put the car in reverse it goes to around 200 and sometimes cuts off. It will also jump up and down throughout the day.

I took the car to Mitsubishi since there is one down the street and they said it was my Throttlebody so my question is can a bad TB cause this type of behavior?

I don't want to replace that if its not the issue.

Also they want 420 for an OEM TB. What would you suggest as a good upgrade from the OEM TB? If I have to replace it I might as well upgrade it now.

 

[phr0st]

There are literally 100's if not 1000's of threads on this already.

The short answer to your question is yes a throttle-body shaft seal or leaking gasket could cause this but there are a ton of other things that can as well.

Before throwing money into the car there are some tests to can do to eliminate certain causes. The link below has a lot of info related to your situation.

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[99GS_Turbo]

Thanks I was looking through other threads but with me always on the go, i had a hard time reading through them all...

 

[JMAR]

You could check your throttle linkage cable or try adjusting the screw on your throttle body... also just try cleaning too...

Sorry I don't have any better info

 

[92AWDHX40]

Start with one thing and go from there one step at a time.