Hello all:
When I come to a stop in my 1986 hardbody (2.4L TBI), the idle speed drops to less than 500 rpm, almost stalls, then eventually jumps back to 900 rpm or so. So far i've:
checked the computer for fault codes (none); replaced air filter, plugs, wires, O2 sensor, exhaust manifold (had a crack), distributor cap, rotor; adjusted valves & timing to specs; adjusted idle mixture; searched diligently for cracked or disconnected vacuum hosing; checked the EGR valve to see if it was binding open by blocking it off from the intake manifold (not the problem); ran a bottle of concentrated fuel injector cleaner through the truck.
This is driving me crazy. The truck runs well otherwise, no change in fuel economy or power. This problem appeared gradually over the past year.
Any suggestions?
Thanks,