I've been through the search forum and found some useful info but could use some help with specifics please! Car is an '87 auto. difficult to start, low idle (around 2-300 rpms). It does not matter if the engine is cold or warm. she idles down immediately. I replaced a very clogged fuel filter last night. fuel pump check valve as well. Throttle response is much improved but the hard starting/low idle continue. Car idled at 500+ a week ago so this is a new development.
Looks like I need to disconnect the MAF and check idle this weekend to see if this is the culprit? what else should I check for? Thanks gang.

Ben

 

Idle stabilizer valve, may be stuck (gummed up). I believe there is a write up on using WD-40 to clean it out.

 

Another possibility is the throttle position switch. If it is not reading idle, it will exhibit these symptoms. Unfortunately there is no way to adjust it, and it's a real PITA to replace, but hopefully the connector is not hooked in.

 

I had an 86.5 that had the same symptoms and i was trying to fix it for a couple of months until one day i notice that the throttle switch connector was not all the way plugged in because it was deteriorating.As soon as i moved it closer to the engine engine connector the idle came back and it was as smooth as a sewing machine.So i orderd a new throttle switch from Dave and Jeannie and it was fixed for ever