Essential info: 87 Turbo II motor, and ECU in an 88 Vert body.

So I got my swapped vert running today after it sitting next to my dads shop for a while. I got it cranked finally (it has been flooding for a long while, recently rebuilt) and the car idled, albeit a little rough. I need to do a few adjustments to it, needless to say.

Anyway, I got in the car to give it a little rev and the idle shot up to 3,000 rpm and I kinda freaked out. I checked the throttle cable to see if it got stuck, but no dice. It stayed at 3,000 for a bit, then came back down to 2,500. I shut it off after a while, but of course it has a crazy hot start issue being an S4, so it wouldn't start up again.

My question is what caused the idle to jump up to 3k? What would be the culprit, so I can check it out?

 

high idle is commonly a vacuum leak or improperly routed vacuum line, thats where I would start off at least.

 

Thermowax.

 

Forgot about the thermowax, if you still have an unmodified throttle body, and emissions, thats normal. If it doesn't properly idle after it is fully warmed up though its a problem. Could be a improperly router vacuum line to the thermal wax too.

 

Yeah you probably just reset the thermowax to cold start procedure. This is normal and will idle at about 2500rpm or so maybe dropping another 1000 rpm till it is warm, and then should come down to like 1500rpm or 1000rpm until you tap gas pedal again and then it should go to normal idle. Well that's how it works on mine, yours might do something a little different. Is the hot start due to flooding issues?