DSMblue

I have been tracking an idle problem with my '87 NA. At first, I was experiencing a high idle condition (anywhere from 1200 - 2300rpm). After taking apart air intake system through the throttle body, cleaned TB, replaced j-boot, visually inspected vacuum hoses, buttoned system back up. After a day or so, idle then went to opposite end of spectrum (approx 100rpm, stalling repeatedly). I unplugged the TPS, and the situation seems to have improved (along with backing out the idle control screw a few turns). However, it still isn't at spec, and the questions I have are these:

1. Should I replace the TPS (again)?
2. Should I bite the bullet and replace all vacuum lines as a matter of course?
3. I haven't taken off the intake manifold (yet), but when I get some time, should I replace or just clean the IAC?

I know that once I get some combination of the above completed, I will need to reset the base idle according to the workshop manual procedure.

Thanks,
Jeff

F18Rep

My guess is your IAC is sticking. A simple (not thorough) test can be done with the intake in place using a 9v battery. You might also confirm that your block temp sensor is not dead. The TPS is pretty simple, easily checked with a meter. Just some thoughts...Bruce

DSMblue

That has kind of been my thought. I will (hopefully) get time this weekend to take off intake manifold to get at IAC and remove/clean it with carb cleaner, and also check all vacuum lines that aren't easily viewed with intake in place.