# In need of some Idle/Throttle trouble-shooting - 200 10V QT



## Dubrunner (Nov 8, 2000)

1990 5spd 200 10V QT -
Started up this morning and had a very "patterned" and erratic idea. 1K - 2k and back down. If you rev the engine, it will stay at about 3K RPM for what seems like an eternity. When driving, it seems fine, but coming to a stop, push the clutch in and - the idle will stay at 3K or more and you kind of have to "kick" it do come down - but then it does the up/down up/down pattern. I replaced the TPS with the updated version about 50K miles ago - so I was pretty sure that wasn't it, but, maybe its bad again (but for $65 to figure that out, I don't have a lot of money to throw at her) ?
*I've checked/cleaned:*
ISV/hoses
T-body/boots
Vacuum lines
Grounds
Checked ECU for water (bone dry)
After all of these, still the same thing. I checked the coolant plug that goes to the cluster (with the four wires) - connection is good, but gauge has never worked.
Any ideas. I'm about to put it up for sale as I've had the car for four years and its starting to look like it'll be a good parts car for someone. HELP!
Thanks All!


----------



## spasticone (May 31, 2004)

*Re: In need of some Idle/Throttle trouble-shooting - 200 10V QT (Dubrunner)*

Did you figure anything out on this?


----------



## spasticone (May 31, 2004)

you can test the throttle switch. it's pretty easy. It can be taken apart and cleaned also.


----------



## dopefishlives (Nov 2, 2005)

Your issues sound very typical of a vacuum leak. Are you absolutely certain that there are no leaks anywhere? Try taking starter fluid/carb cleaner and spraying around the intake tract and various vacuum connections. If at some point your idle changes from the spray, you may have found your leak(s). Another test is using a smoke generator to pump a non-running engine, it should find a way out via any possible leaks, if they exist. Again, another option is to run the smoke machine using the 'wand' around the running engine and see if it is pulling the smoke/air in from any areas that are not intended. 

Good luck with the search, I have a bit of a surging idle when cold, but I think it is related to my ISV, I just haven't had a chance to look at it yet.


----------

