i got my car back from the mech. and he said everything is fine.....except......when it's cold it idles rough so it needs an MPS...is this right? it's a 2L 1973 about 90K miles on it.

First check for vacuum leaks.

It could also be the AAR (Auxiliary Air Regulator) is stuck shut.
With the engine running and cold, pull the vacuum line off the air cleaner assembly coming from the AAR. Put your thumb over the end of the hose and you should feel it sucking air. If you don't then your AAR is not working properly.

It could also be related to your head temperature sensor.

a CHT is cheap--i would start there.

also I would check the AAR as well.

for me personally, I couldnt ever get my AAR to un-freeze, so i bumped the idle speed a little bit....

ran around 1100rpm hot....

I find it unlikely that the MPS would have anything to do with crappy cold running. If the MPS was bad, the car would run bad all the time. I'll agree with everyone else and bet on either the Cylinder Head Temp sensor or the AAR. MPSs are damn expensive too, so not something you want to randomly change.

When the car is hot, it runs fine?

QUOTE (mike_the_man @ Aug 12 2005, 06:45 PM)

I find it unlikely that the MPS would have anything to do with crappy cold running. If the MPS was bad, the car would run bad all the time. I'll agree with everyone else and bet on either the Cylinder Head Temp sensor or the AAR. MPSs are damn expensive too, so not something you want to randomly change. When the car is hot, it runs fine?

I cry severe

Check the CHT or the AAR first... that is if it is running well hot.