Lately my '83 944 has been having idle issues. It will drive just fine and doesnt stumble or anything, but every other time I release the gas pedal and let it go to idle it will go down to about 600 rpm's and then slowly come back up.

I'ts not the shudder issue because im running the FRWilks chip with shudder fix.
Any idea's what the problem could be?

I think my DME is crapping out on me. Maybe the wilks chip has something wrong with it?
Ive been noticing people putting late DME's and AFM's in theyre early cars.
Can I do this to my '83?
Do I just have to swap the AFM and DME? Or is there more to it?

 

Under the intake manifold is an auxiliary air valve that functions as an idle stabilizer valve. Yours may be clogged. You can take the hose off and spray some carb cleaner (with a cold engine) to clean it. Removal requires taking the intake manifold off. If you do take the intake off that would be great time to replace all of the vacuum lines.

 

I thought it could have been that, but it just seems electrical to me. I cleaned that out about a month ago.
The car idle's and bogs like the iginition is screwed up. I checked the plugs and they seem to be clean and normal. It only does it when trying to idle, if I hold the gas it'll rev just fine 2k rpms and above.
Im going to see if I can get a early DME for cheap or if someone has one that I can borrow.

 

Have you tried retracking the AFM wiper arm yet? The 83 I had had all sorts of issues with idle and dead spots until I did this. I have a MS Word file with pics I can send since the link has moved a few times.

 

I retracked the wiper arm according to clarks garage a while back.
It has no deadspots other than 1-2k rpms being really rough. It only does this when it feels like it. Im going to rewire the AFM wires and see if it fixes it.

 

Well, my dad found out that if you hold the AFM wire just right it'll run perfectly fine, so I ziptied it to the air hose next to the airbox and so far its running great.
Both cold and warm idle are back to normal.
Im still going to rewire that section of the harness but at least it runs, for now.
Stupid old brittle wiring!!!