'87 R10 suburban 350 V8 TBI stalls at lights - suggestions?

[skizzik]

Hello Chevy experts!

My 1987 R10 Suburban 350 V8 TBI (K family) stalls at lights but will recover if I shift it into neutral fast enough while I hear it about to die. It also commonly happens when I'm pulling into or out of a parking spot. (Does this mean the official symptom is 'stalls when RPMs drop too low?')

I'm not a car expert, so I've done some googling and here's what I've done so far and here's what I know:

- first I replaced the fuel filter and air filter
- then I cleaned out the throttle body and IAC sensor with throttle body cleaner. Neither one seemed very dirty
- while doing that I watched the injectors spray and they appeared to be atomizing the fuel properly
- checked for vacuum leaks by spraying throttle body fluid on my hoses and at the base of the throttle body and did not hear any hissing noises. The previous owner removed the charcoal evap canister so that hose has a bolt tightly screwed into the end of it. Sprayed that too and didn't hear any hissing.
- replaced my spark plugs
- cleaned out my PCV valve. It sounds like it rattles properly when I shake it.
- fuel pump completely died last week. I replaced it, hoping it would solve my stalling problem but it didn't.
- engine light is not on. Sometimes it comes on if the truck is about to die but always goes away after I restart the engine or if the engine recovers. I haven't checked for error codes because I haven't found anyone that has the older type code reader.
- idle is already pretty high. Mechanic told me he was afraid to turn it up any higher.

Anybody know what I should do next? What can I do myself and what do I need a mechanic to do? Besides this stalling problem, this truck still drives great.


Thanks,
Mike