Madcap

Is it normal to have the idle jump to 1250 (sometimes even a tick higher) when you put the transmission in Park? More often than not, this happens to my '96.....even when at operating temp. I deliver mail and I'd say I have about a 70% chance this will happen to me, as opposed to the idle staying at 750 when I park. Sometimes I can get it to relax by revving the engine and then it settles at 750, but it's not the norm.

4.3L XJ

No, not normal. I would suggest you need to clean and possibly replace your idle air controller. Fairly simple job

Madcap

I'll take a look at the idle air controller, but it's new as of about 2200 miles ago. Is it true the "reset procedure" on those is to rev up to 2000rpms or so and kill it from there as opposed to an idle?

Also replaced these parts, FWIW:

Distributor Rotor
Ignition Starter Switch
Distributor Cap
Ignition Coil
Air Temp Sensor
Distributor Pickup Assembly
Crankshaft Position Sensor
Idle Air Control Valve
Throttle Position Sensor
Manifold Absolute Pressure Sensor
Throttle Body Mounting Gasket

4.3L XJ

But is the channel clean. If not it can stick

Madcap

Roger.....I'll take a look. I think I edited as you were typing.....did you see my added "reset procedure" question?

Thank you.

Spencer_P

Worth trying. Disconnect the battery for 30 minutes then follow this procedure.
Idle for 2 minutes in park with A/C off, 2 minutes in park with A/C on, 2 minutes in gear with A/C on, 2 minutes in gear with A/C off.

Madcap

My AC is non-existent.....but is it just about some electrical signal being sent, as opposed to actual AC flowing?

Spencer_P

I believe it so the compressor can put a load on the engine. I have heard of another relearn procedure or drive cycle but I'm unfamiliar with it. I would do the one I posted minus A/C then take it for a drive on the highway one way and through town on the way back. If someone can chime in with the proper drive cycle I'm sure it'd be better.

Madcap

Turns out my throttle body was filthy. Figured I'd say that in case someone else finds this. Thanks for responses everyone.