thetremendousti

In my '81 ZX N/A whenever i cold start it, it maintains a rough idle until driven up and down the block a few times or on the freeway. Why is this, could this be timing? How do i check the timing, would it be easier to buy a "timing light" and a haynes or to just take it to "pierre'z" in hawthorne?

NismoPick

Classic cold start valve and/or air regulator problem. SEARCH for "cold start" and you will find your answer.

duowing

It could also be related to the Cylinder Head Temp Sensor. My car though would idle alright, it was just that it would pop, sputter, and just really be hard to drive when cold. Oh when it's cold and idling weird does it run fine otherwise?

thetremendousti

yeah it runs fine, it just coughs and sputters once or twice when you cold start it. otherwise as long as it's warm it's good to go.

duowing

My bet is on the air regulator.

thetremendousti

well today i cleaned out the AFM and everything in it was surprisingly very clean, and i adjusted the carbon contacts so they're "fresh" just a bunch of orange stuff in the box, looked like rust or soemthing....odd....but that's all that was in there, and the idle is still wierd, it is 500 when i start cold and warming up to about 800 so what's going on here?! Yes, i know i'm asking this in 2 different places but the other thread isn't coming up as recently posted....

NismoPick

Did you ever check the cold start and air regulator???

duckyz

Geez....let's start at the beginning.

What's your air filter look like?

Start at the easiest thing and go from there. My Z doesn't like the transition from summer to winter, but I have things pretty dialed in and all I usually need to do is adjust the idle screw.

thetremendousti

yeah filter's fine, but i REALLY don't know what to do about the idle! I REALLY had to crank it this morning to get it started and it died a few times, then sputtered, its getting worse sounds like. Cold start valve you think?

NismoPick

For the third time....