740GL symptoms: Rough Idle & Stall while cold

You had it right the first time - classic for throttle body glop, including the lack of problem when warm... I don't know why. Especially clean the passage at the bottom that goes from each side of the throttle butterfly to the knurled idle adjustment screw. I count the turns as I screw the idle adjuster in, then remove the screw for cleaning and reinstall it and set it the same number of turns from closed.

The Idle Air Control valve under the throttle body also needs cleaning at the same time. Expect to use half a can or more carb cleaner for the pair of them, and you should be good for a couple of years.

Old plugs, bad wires, restricted injectors, vacuum leak, what have you checked? What codes sre present that aren't triggering the light?

Bob

Sorry, posted before checking. I haven't had a free weekend in a while to even pop the hood, so the car keeps getting gradually worse. I wanted to get a list of all the possible things it could be based on the symptoms, gather the parts this week, and then tackle repairs in order of likelihood this weekend.

Hopefully it'll be the throttle bodies like Michael Pardee suspects -- but I appreciate your other suggestion and will check into those areas, too.

Michael,

Thanks for these tips. I cleaned the TB today and it fixed my idle problem. I was amazed at how stubborn a lot of those deposits were. Took several applications of cleaner and lots of scrubbing with the toothbrush to get them off. This was the first time I'd ever cleaned the TB, and I've owned the car from 60K to 180K. I think it's a good bet it's the first time it's ever been done.

Also replaced the crank position sensor while I had the hood up. Hopefully this will cure my hot-start problem.