idle bounce only after throttle or grnd/ten jump
 

Looks like i got a problem with my '90...

Last week i went to start it, and it barely stumbled to life. I assumed it was a problem with the injectors since i never had them cleaned after i got them, so i sent them out. They came back and were fine.

Now after installing them, the car starts, and idles fine, until i give it gas. After letting off, the rev's drop to ~150-200rpms as it almost stalls, then rise back up to ~900-1000rpm, then drop to 500, and finally settle at 900.

The dashpot isnt the problem, and when grnd+ten are jumped, revs constantly go from 200 to 800 to 200 and so on until it's removed.

Any ideas?

To me it sounds like the idle air control valve. I had the same problem on mine and that's what it was for me. The GRD TEN thing seems weird to me, but i never did that when i had the problem. It is either that or a vacuum leak somewhere.

tested vac and it's around 19-20lb when the idle is steady so i dont think there's a leak

Looks like i'll have to try and clean that idle valve. damn.

can't a weak alternator do this sometimes?

Actually that would make sense for the almost dying part after giving it gas, but what about the GRD TEN part? What exactly does that jumper do? I know what function it serves to do it, but what changes when you do that? That would be where i would start. Find out what making that jumper does in the first place.