what could this be?

Hi,
Have and '87 Blazer 350,tbi,AT,4wd that is giving me some off-idle missing and light-to-medium throttle engine missing-kinda like its 'chugging', like its about to die... Just noticed it the last coupla' weeks. I also notice that it occasionally will stall on me during light accel from a stop. Seems to idle ok, though i do hear it miss sometimes. And i do notice the exhaust seems much hotter than normal.

I have replaced the plugs, wires, cap/rotor, pcv, fuel filter, and had the timing checked.

Had a code 43 in November and changed the knock sensor then.

I know diagnosing these problems are a pain, and i dont expect a "silver bullet", but any help would be much appreciated.

Thank you,
James

Have you checked EGR valve? It could be sticking.. :banghead:

Have you checked EGR valve? It could be sticking.. :banghead:
you are essentially right - it was the egr valve. had a 'weak' spring. oh and a leaky intake manifold.