Hi all. OK my idle is rock solid, no pulsing;however, it will sit at about 1300 for about 10-20 secs, then drop down to 900. TPS is A-OK. Very very very little popping or anything, but I have straight thru exchast so a little popping is expected. It just bugs me it doesnt drop right down to 900. I've fiddled and fiddled and out of ideas. Motor has about 6k on a rebuild, mostly stock save a slight street port. Also, it's a 91NA.

Ideas?

 

Do you have stock emissions and warm up stuff?

I know there is a start up assist that is supposed to rev the engine to 3k, and then let it drop to 1.5k and then it will slowly go from there down to normal operating RPM.

Check all that stuff thermowax and stuff like that.

 

cold start, warm the car up to normal op. temp then adjust the idle accordingly..then it should work fine..

:AA:

 

Yeah I've tried all that. I have stock exhaust minus emissions crap. My cold start works fine.

Yesterday, I took it out on a little jaunt on the freeway and took city roads back home. Being in Phx that warms it up pretty well. After idle dropped down to lowest point I adjusted to 900 then back out for some city driveing. Same thing...come to a light or stop sign, push in clutch, and I would say 8/10 times drops to 1300 or so for about 30 secs then drops to 900. This doesnt happen when I have AC on though which is odd to me. With AC it drops right down to 900.

Any other ideas? I can live with it, but it seems to me something is off...

 

Dashpot. If you didn't remove it as "emissions stuff"
It's a little spring loaded thingy that keeps the throttle plates from snapping shut abruptly. You can adjust it or remove it but you'll get more popping if you do.

 

hmm didnt think of that I'll give it a try