Normal?

Hi,

'88 XJ Reman 4.0L & AW4 Tranny (less than 5k on them, odo says 135k).


Whenever I start the engine it revs around 2k rpm and after about 3-5 secs drops down to around 800 rpm.

***Is this normal?

I also recall seeing a post that said placing a drop of oil on the IAC Spindle helps?

***Is this Spindle found inside the Throttle Body and how to lube it exactly?

Thx.

I dont know about Jeeps, but most older chevy Pickups do this, maybe not 2k though. They do have a high idle that can be kicked down reving the engine once. This is all part of the choke. Again I dont know if Jeeps have this and if it is carb'd or FI might make a difference as well.

No this is not normal. I saw a video of a renix jeep cold starting, and his revved up to 1400 and INSTANTLY dropped to idle.

Mine does the same thing you are doing, hot or cold. I believe it's either

A) dirty throttle body (that you would have to pull out to cean)
B) a vacuum leak (most likely)
or
C) faulty IAC


Try removing vacuum lines and plugging them and see if it helps. If it is a vacuum leak, it is most likely your intake manifold though. Try tightening the bolts. If all else fails, you can get a new gasket for it.. Although it's a royal pain in the arsehole to replace.

Also you can check the latch relay. If it is failing to delay the power down it will still be letting the ECU think the engine is hot or warm. That relay is one of the ones located on the passenger front wheelwell under the hood. I think they are all the same relay so you can shuffle them around to see if it makes a difference. Be careful as one is your fuel pump relay and it needs to be a good one or you will incur a no start situation.