I am going nuts over this one. My 1995 4.3 V6 started and ran rough....stalled, then after several minutes cranking did start, idled OK, but as rpms increased towards 1800-2000 rpm ran quite rough. I could drive, but very rough getting moving, and when at highway speed ran better. I had it not start again and looked it over, pulled the wire from coil to distributor and reinserted it making sure it was tight. Success, it fired up and ran perfectly...the next day it ran perfectly then died on the side of the road where it sits. It turns over but will not start. Bad coil? I haven't been able to find anything in the forums that fits these symptoms. I had a shop replace the transmission prior to this, but can't see how that would affect ignition. Any ideas out there? It is my get around vehicle and after replacing the tranny am short on funds and can't afford replacing everything one bit at a time until it starts. I am going to get a buddy to bring his multimeter over and check the coil before anything else. I am open to suggestions as to what this might be.

 

Hmmm, interesting problem. Hard to say, but you could check to make sure the rotor is nice and tight inside the cap on the distributor. Mine came loose as I was driving down the highway (thanks to the shop that stripped out the threads) and left me stranded until I figured it out. I also know that if the Crankshaft Position Sensor goes haywire than you won't be going anywhere either. But I know you don't want to just throw parts at it until it starts running, so a multimeter is a good idea. Search the forum and you will find all the reading you are supposed to get.

 

Years back I had a similar issue on my 94. It was a sticking EGR valve. Ran great at hiway speeds but terrible at idle or around town. It's pretty easy to remove and clean. Good luck and let us know what you find out.

 

Thanks, but I found that it is a fuel problem. A squirt of starting fluid and it would fire right up then die. I replaced the fuel filter, the old one was plugged, and got it fired up and running. Drove it around a few blocks then back home, idling in the driveway it died again. So I am thinking fuel pump. I remember having a similar problem a few years back with an 89 Chev full sized 4X4 P/U and had to replace the fuel tank and pump due to rust. I am starting to think that this might be the problem.