Ok, I have spent hours researching this problem before posting, but I just can't find exactly what I am experiencing. My 1996 4.3 liter 4x4 has 182,000 miles on it, and has been well cared for the year and a half we have owned it.

Yesterday we were driving around for about two hours and made a stop to pick up some items before heading home. When we tried to crank it to go home it did nothing...no click, engine did not turn over. All interior lights, radio, windows work. Battery is new. We got a ride home, and my husband and father in law went back to look at car and it cranked up without a problem. We drove it later that night to a friend's house, the store, and home with no issue. Today we used it to haul feed up to the barn thru the mud (it has been raining all week), had to use the 4 wheel drive and it worked fine. We turned it off and got ready to go to town and it did the same thing?! About two hours later I was walking the dog and reached in and cranked it first try!

Here are a few things that have been recently replaced - battery, serpentine belt, shocks, fuel pump, fuel filter, alternator, distributor cap, and rotor button. It has been tuned up and the EGR, MAF, etc were disassembled and cleaned shortly after buying it. We just had the transmission rebuilt last month after the sun shell gear fractured.

We took off the ignition control module today, and had it tested four times and it passed. The only other problem this car has is that when you put it in gear the rpms stumble badly but it recovers. It has started to idle a little rough at lights, but not terribly. We found a plugged vacuum line and fixed that tonight, but the rpms still drop when put into gear.

So, where do we start? This is my (the wife's car) and I always have our two young children with me...I am worried about getting stranded in it. We also just put almost $1000 into the transmission so we want to keep driving it! Some of our friends think it is the linkage, but we inspected that, maybe the safety neutral switch was damaged... but would that be an intermittent problem? How about the camshaft position sensor? Thanks for any help!

 

Have you read https://blazerforum.com/forum/engine...not-run-45944/ ?

It may not be exactly what you're looking for or needing specifically but it will probably help figuring it out.