After replacing the LIM gasket on my 3rd gen, the hunting idle has disappeared.

It has been replaced by an idle that is way too fast.

When the coolant temp hits about 185 degrees, the idle jumps immediately to 4000 RPM. The idle speed prior to that is about 1700.

The TPS voltages as read on the PowerFC commander are just slightly out of spec, about 0.06 volt.

I will adjust them within spec, but need to know what else I should look for.

What part of the idle system would cause the idle to jump to 4k and stay there when the car gets up to temp?

This is a single turbo car, stock motor, with Power FC.

FWIW, I didn't do the single turbo conversion, so I'm not sure what all changes were made to go single turbo.

 

It is obious that you either have a large air leak, your throttle is sticking open, or something with the throttle body if FUBAR.

Start being a mechanic, or take it back to the people who did the conversion.

 

I had the same problem before and it turns out to be either the brake boost hose or the oil neck hose.

 

i know if you did the throttle body coolant deletion mod can casue a high idle if you dont wire the open...i could be wrong though... just a thought, someone add.

 

Well, it might be obvious if you know what to look for.

The throttle is not sticking open.

Large air leak? Maybe, but not too likely at this moment, as the gaskets have all just been replaced. The large air leak was causing the hunting idle, which is now gone.
(1500-3500k)

Take it back to the guy that did the conversion? Not an option, out of business.

Become a mechanic: that's what I'm doing, and why I'm asking for help.

Any more helpful suggestions?

 

Thanks, I will check those.

 

Thanks, but the throttle body coolant lines are still there.

 

It's got to be somewhere after the TB and before the LIM.

 

DAPDAS^2

 

The problem turned out to be 90% TPS adjustment, 10% Fast Idle Adjustment.

Obviously not an air leak.

 

I think you have your percentages reversed. OK tell us what you really did.