924Board.org

[Greenie]

Sorry for a re-post, I think I originally posted int the wrong forum.....

Have a very nice 87 924S that I took over from a relative. Has a true 35,000 miles. Went ahead and did whole front engine job even though it seemed o.k. Also did complete "tune-up" with plugs, rotor, cap etc...

My only issue is a rough idle. Here's the rundown.

Idles rough (lopes), but above 1200-1400 rpm it purrs very nicely.

At idle, if you pull plug wires, it gets worse by pulling #2, #3, #4. But, if you pull #1 at idle, nothing changes, still the rough lope, but not any worse (telling me #1 isn't firing at idle)

If I give it a little throttle to up the idle above normal (2000-2500 rpm) and repeat the above procedure of pulling plug wires, it has a noticeable effect with all #1, #2, #3, #4. So, this tells me that above idle, #1 is firing and contributing???

The car is nice and smooth running on the road, it's just that idle that's giving me trouble.

I had the injectors cleaned and verified by an Injector Doctor. I'm at a loss and would appreciate any insight.

Could the injector just not be working at low pressure??
Is it as simple as changing the Idle Speed Regulator??
Fuel Pressure Regulator or Damper??


Thank you very much for any feedback.......

[gohim]

Have you tried swapping the sparkplug wires between two cylinders?

Have you tried swapping injectors between the one that appears to be working, and the one that is not firing properly?

This might give you a better idea of what is not working without spending any money.