My 92 S10 Blazer 4.3 "W" engine has taken spells running very rough, cuts off, and will not idle. I can hold the engine at high revs and it will smooth out some. When it gets really bad the SES light will come on. I suspect the EGR is at fault. I jumped the A & B terminals on the diagnostic connector, but the SES light will not flash - not even the code 12. I turn the switch to on and the SES, check gages, and battery icon lights remain on and the SES will not flash. What could be causing this ? It has worked in the past.

 

Try taking your neg. battery cable off for a minute or 2 and see if that helps. Maybe the computer just needs reset of something.

 

No way, do not remove the battery cable or you will lose the error code it threw. Go to autozone and have them read the code for free. I read somewhere that the jumper cable way to read a code doesn't always work for some vehicles. Worked for me thought, 94 s10 blazer 4.3 W.

 

Thanks for the suggestions. This seems to be a problem no one has encountered. I've used this method a couple times in the past, ( probably the last time about 1 year ago ), and each time it worked just like it was supposed to - spit out the codes. I'm wondering if this has something to do with the truck running ragged. Anyway I'm going to take to AZ and see if they can pull a code with their scanner.