99 D with 318 and 160K miles will not ide fast enough to keep engine running without keeping your foot on the gas. This problem has been on-going for the better part of a year. Problem ocurred only sporadically on cold start-up at first but eventually got to the point where it was constant, at start-up and anytime it was idling. To date, I have replaced all the following component / parts;
Battery
Idle Air Control Valve
Throttle Position Sensor
Cleaned Throttle Body
Both O2 Sensors
PCV Valve
Plugs
Wires
Cap
Rotor
Coolant Sensor
Probably something else that I've forgotten by now. I resorted to drilling out the throttle plate stop screw and running it in enough to keep the throttle plate slightly open. Even then it has died a couple of times and since my 19 year old son is driving it now to college, I finally just pulled off the vacuum hose from the PCV valve. Idles way to high but at least it keeps running. I know that running it like this is gonna cause carbon / sludge problems long term but I'm flat outta ideas. Has never, ever thrown any codes. Dealer has no clue so that is not an option. My next move is to replace the PCM but I hate to part with that much jack just on a guess.
HELP!!!!!!!!!!!!!!!!!