Warm the engine, shut it down, disconnect the idle stabilizer valve,
start the engine, check the rpm. If it is steady, you have a stabilizer
valve problem most likely, though it could be the stabilizer control.

On a cold start the ECU, causes the stabilizer valve to regulate the
fuel injection so the engine won't die. Once warmed up, the ECU cuts the
stabilizer from the circuit, more or less. It doesn't operate once the
engine is warm. In a sense it's abit like a choke on carbureted engines,
which adds more fuel to keep the engine running when cold. Except that
it doesn't work exactly like that. But basically the result is the same.
The engine will idle when cold.

John Rodgers
88 GL Driver

MtnGal wrote:
>
> Haunting/Hunting idle
>
> It's driving my crazy!!  Can anybody tell me what causes this?
>
> The van drives great on incline and no jerking
>
> New O2.
> New temp2 (Last season)
> BUT, runs xxrich (10 mpg!!!!)
> I have never replaced the cat or muffler which both look in need of TLC
>
> Any advice?