Still stumblin'

[RossGN]

Still stumblin' - FIXED!

Ok...this thing's getting on my nerves. Stock 86 GN. Spits and sputters below 2000 rpm...runs fine above that. Before my laptop crapped out, it was showing lean below 2000 rpm.

Checked for and repaired minor vacuum leaks.
TPS & IAC look good...reset per GNTTYPE instructions...no change.

New oxygen sensor...no change

fiddled with cam sensor...set it right at the voltage drop and tried setting it 1/8 turn counterclockwise after voltage drop...no change

Cannot find any vacuum leaks

New plugs and wires.

Plugged off EGR...no change

Tapped on MAF...no change

Tried rebuilt MAF ...no change

Cannot find any exhaust leaks


What should I check next?

 

[NJTurbo]

What is fuel pressure at idle?

 

[RossGN]

Fuel pressure is about 39psi at idle...43 psi line off

Also changed fuel filter

 

[NJTurbo]

It sounds like you covered alot, however take a can of carb cleaner and carefully spray around intake gasket see if rpm's change. It sounds like you may have a small vaccum leak. I would also pull out IAC and clean TBI unit and reset IAC and TPS. I have seen were TBI unit is dirty and Iac does not fuction properly and idle surges then stalls.

 

[RossGN]

Thanks for the reply

I sprayed starting fluid at all possible leakage areas (that's how a found and corrected the vacuum line leak )

I have cleaned throttle body and reset IAC per instructions at GNTTYPE.org

 

[RossGN]

Ordered a module today....we'll give that a try

 

[Dan Thompson]

There is a gasket under the IAC. I found mine was missing and was able to get one at the dealer, though it was a while back.

 

[RossGN]

Replaced the ignition module...no luck.

Went to the parts store and bought another can of ether to check for vacuum leaks. Don't know why I didn't catch it on my first round, but found the leak. There was only a partial gasket at the turbo inlet bell. Sealed that up and this thing idles and runs like a champ! Thanks for all the help guys.