OK, first: I've scoured the threads and have found others with similar problems, some explained better than others, but none with my simple yet confounding symptoms.
I bought the Blazer new. Traded my 91 Cavalier which I bought new. Am en engineer and have never had my vehicles in the shop (except for warranty work) - I've done it all. I'm the poster boy for Blazer TSBs - suffered through nearly all of them. DexCool is evil.
OK, got sidetracked. I'm worried I'm going to have to have the Blazer towed to the dealer for repair. The thought is worse than emasculation...
So - DTC P0340 set twice. This has been a recent, intermittent issue. No other codes. Always after air period of driving at temperature. Tech would jump wildly, peg-out high, and after a brief period of rough, crappy performance would settle at 0rpm and driving would be normal but lacking power.
Replaced the cmp sensor. Truck wouldn't start - just cranked and would cough a couple times when the key was released to run.
Put the old sensor back in. Same thing.
Replaced the entire distributor, cap, and rotor. No start.
Tested the supply, ground, and signal at the cmp all is fine. Working out of the 3-volume service manual set for my truck.
I'm at a total loss. What should've been a quick sensor replacement is about to become 3-day ordeal. I've worked through the "cranks but won't start" section of the manual and that posted here- but to no avail.
It simply can't be so complicated...
Thanks for any thoughts!!