when i start the car on a cold morning (30 degrees) the idle jumps around a little from 1000 to1300 rpm for about 30 seconds then goes to the normal 750. i usually let it warm up for a few more minutes and start driving, when its fully warmed up it always idles at 1000 to 1200 sometimes even higher and the car is a stick and if i put it in nuetral and coast to a stop it usually stays at 1600 until i come to a complete stop, then it goes to 1000 or 1200 like usual
the car has a decent amount of mod;s with the stock chip...and maybe it isnt going into closed loop cus of the 160thermostat

world products sportsman2 iron heads2.02/160valves
slp roller cam 502/510 224/230 at .050 1.6 roller rockers
52mm t.b. slp runners
hooker shortys to a 3 inch catback
adjustable fuel pressure regulator set at 53psi
5speed

 

I am assuming the car is GTA that originally an automatic. I have an 88' IROC that has extemely similar symptoms, I think the problem is the swap to the manual tranny, I had the stock chip in my car with the automatic and all the engine mods and it was fine, when I put in the 6 speed it was acting like you described. The only thing I have been able to come up with is that a manual has a clutch anticipation switch which changes how the IAC works. I know the switch is on the peadal but how to hook it up to the ECM I dont know. I also assume you will need an manual tranny chip.

 

i never hooked the switch up either but im pretty sure theres a purple and yellow wire seperate from the rest of the harness underneath the dash right near the clutch pedal that has to get connected to the switch

there should be a something in the tech articles on the auto to manual swap link about it

 

You should have the 2 big wires hooked together on the plug that was on the old auto shifter. Either hooked together or wired to the clutch safety switch. Leave the orange and black wires disconnected. Part of the problem is the auto bin that your using. As far as the other things you've set your minimum air adjustment and all properly?

 

yeah i have the 2 big wires on the harness for the auto shifter hooked together...when i 1st converted it to stick the car wouldnt crank over unless they were connected

yeah i have the TPS and IAC set..ive gone over them a few times and ive also messed around with the idle screw on the throttlebody...but no matter how i set the tps iac or the idle screw
once i start driving afters its started and warmed up it always idles at 1000 when i completely stop....i can start the car and let it sit there for 20 minutes and it will idle at 750 but once i drive it goes to 1000
and like i said if i coast to a stop it stays at 1400-1600 until the speedo says 0mph

 

Put the stock 195 thermo back in and see if it will now idle correctly. Bet it does. After you try it and you want to go back to the 160 thermo get ready to do some PROM burning. And no it isn't a closed loop problem.

RBob.