hey i have a bit of a problem. Just got a 93' blazer with the 4.3 in it about a month ago. been running fine since i got it...until now. Was coming home from work today and noticed about half way home on my 7 mile drive that whenever i let up on the gas if would nearly die and i'd loose power brakes (scary on windy mountain roads) Anywho got home and as i coasted into the driveway it died. Now it's really hard to start, barely idles, if not dies when my foots not on the gas, and smells like it's running really rich. It only wants to run on about half the cylinders when it (tries to) idle but once i get it past about 2k rpm it smooths out and seems to run fine. I was thinking it could be the fuel pressure regulator might be stuck open or something and allowing too much fuel while idling? idk, i'm no genius at this. any suggestions?

 

Do yourself a forum search on CPI INJECTOR and you will find a plethora of info for diagnosing and repairing the leak if you have one. You have the symptoms. Dont forget to get the injector harness for 8 bucks and solder than on while you are in there. Its something you can do at home with hand tools. These are just parts that dont last forever, and are probably the most common poor run faults I see around here.

 

actually on my way to work last night it seemed to have fixed itself. was coasting down the hills in neutral with my foot on the gas to keep it from dieing and after a while i noticed it wasn't trying to die anymore. sure enough i pulled over and it was idling just fine. Dunno if that would still be an injector problem (which btw the injectors were replaced 2 months ago) but if this new info makes you think otherwise i'd like to hear your new theories in case this happens again

 

If the Injector(s) were replaced, then you have a TBI engine, not a CPI... Thus making my information useless to your diagnosis. Either way, you want to check for engine codes, and fuel pressure and let us know.