in the morning when i start my car cold it will start and go up to 1500 RPM which is common so i just tap the gas and it goes down to a rock steady 750 RPM but on my drive to work as the car warms up the idle will slowly rise every time i come to a light till eventually my idle is at 1500 RPM and wont go down.

now if i shut off the car and let it sit for 10-15 min and the start it back up it will idle at about 500 RPM and be bouncing around trying to keep running and as i drive again it will go up but this time up to a rock steady 600 RPM

now again if i let it sit for about an hr to 2 hrs and start it it wont idle at all ill have to keep my foot on the gas pedal every time i come to a stop and again after driving it will eventually come up to about a 500 RPM idle but will still dive and catch itself just as its about to stall.

back ground...
running premix
no cats
no ACV
no bac
no air pump
no A/C
no power stearing
5 speed
no vac leakes ive checked about 10 times and did find 1 about 2 months ago and it didnt seem to chnage nething
the thermo was IS STILL intact could this be causing my problems some how?

thanks in advance
pinfield

 

you have no BAC, so anything that can prevent the throttle blades to come back to the same position could be the culprit:

- thermo valve cam
- throttle cable
- deceleration dashpot
- more along those lines I can't think of.

TPS could also be a factor but not sure if no BAC.

assuming the base idle speed is set high enough (does not go down too much when elec loads are applied) and no vacuum leaks.

Hugues -

 

No water going thru the thermowax or a dirty thermowax device i.e. corrosion in the water passages. That would explain the *never the same* idle. Clean and repair same.

 

is there a way to just disable the thermowax with out removing it or taking off the TB? so that i can see if that really is the culprit? i had suspected it was that for awhile but didnt know of a way to disable it without taking out the TB which i really dont want to do any time soon but will if i have to

also the TPS was bought new and set perfectly

 

on the turbos you can get to it.

i have some stuff removed and can get to it while running to check if it's the cam. I can lift up on it to make sure it's out. If the idle changes i know it's not warm enough.

i guess u could watch your tps and when u lift the cam if the resistnace changes u know it's not out all the way. This would be a bit safer way if you not comfortable with your car running