Ok so my 87 SC has been having some trouble running. The dude who i bought it from replaced the distributor and carb, but said he thought the timing chain might be slipping. I was skeptical but went ahead and replaced it.

Now the engine runs after setting the timing, but the idle is really weird. it seems to idle good, and then down low, then good, then back down low again. This doesnt really happen when it's driving., only when the motor is at idle. Sometimes it will die just sitting there. A little gas every 20 or so seconds seems to even out the idle though. I have no idea what this could be?!

Only one other problem I have, I'm not sure if its related. When shes cruising in 2nd or 3rd, and you hit it, she doesnt downshift just keeps going in the current gear. I'm thinking that might just be a vaccuum line and I'm looking into a shift kit and moser rear/gears so i'll be pulling that apart anyway.
Any ideas/wisdom? Thanks 3rdgen!

 

Anybody? buuump.

 

Acouple of suggestions Vacuum leak some where get acouple cans of brake cleaner spray the vacuum lines around intake and everywhere else if idle changes thats your leak 2. Bad sensor tpi iac if they are used 3. Bad rings losing compression do a compression check 4. Idle/air ratio off Start with the easiest and work up to the rings any codes

 

egr valve or selanoid screw up idle