2G Replaced throttle body idle problems?

[BeagleTalon]

Hello all, I'm new to the forums as of today. No worries, I have been trying to find the problem on here for a few hours now and have read through a lot of posts but nothing I can find is related fully. ANYWAYS, I have a boost leak and I've been trying to track it down. I've just cut and replaced my TB gaskets. Now when I start it Roma surge from 1500 down to like 800 then back up to 1200 down to 400 and so on and dies. (Numbers are approximate)

 

[spyderdrifter]

You could have bad throttle body shaft seals. There are write-ups on here explaining the procedure if that is your problem. I've done it once myself and it's not too difficult. I would also test your Idle Air Control motor. Perform a leak down test too. If it leaks, fix the leak, then do the test again to see if you have more leaks. Good luck.

 

[ceedawg]

You could have bad throttle body shaft seals. There are write-ups on here explaining the procedure if that is your problem. I've done it once myself and it's not too difficult. I would also test your Idle Air Control motor. Perform a leak down test too. If it leaks, fix the leak, then do the test again to see if you have more leaks. Good luck.

You mean a boost leak test,a leak down test he does nor need to do because that is when ypu are checking the mechanical condition of the motor(rings,valves,HG). Thought I would throw that in there. Lol

 

[spyderdrifter]

Why wouldn't a leak down test work? A stuck valve would leak air, and since the OP has a non-turbo model, there's not much to look for an air leak before the throttle body. I know a boost leak test can be done on more than a "boosted" engine, but there's not much there before the throttle body that would leak on the OP's car.

 

[ceedawg]

Why wouldn't a leak down test work? A stuck valve would leak air, and since the OP has a non-turbo model, there's not much to look for an air leak before the throttle body.

Read it again the op says he has a boost leak! So the car is turbocharged not NA. And yes I agree it can be a ISC issue or leaking seal at the throttle body as well. So boost leak test is a must.

 

[spyderdrifter]

Well ,I guess you're right, he did say boost leak. I must have mixed this up with another post I was ready earlier. In that case, a boost leak test would be relevant. Guess this it what happens after working all night.

Just looked through my recent posts, I did mix this one with another that the original poster specified Eclipse GS.

 

[DogWhistle]

Did the car idle well on the old throttle body? Why did you think you needed to replace the throttle body? Did you use the Idle Air Control Valve that came with the newer throttle body without testing it first?

The Idle Air Control Valve is a small electric motor on the bottom of the throttle body. It's job is to maintain the correct air/fuel ratio at idle.

There are two possibilities that could cause your condition: 1) a bad IACV, or 2) an over-busy IACV because of a vacuum leak, possibly between the intake manifold and head, or cracked vacuum lines.