I have a 1992 S-10 Blazer with the 4.3 liter TBI. About a week ago I noticed that the my Blazer had the tiniest miss while I was sitting at a stop light. I thought nothing of it and went on with my day. Well, over the next few days under a load (while going up hill or accelerating) the engine would practically die...but for just a second. It would lurch forward then pick up where it left off. I thought that I may have a bad plug or plug wires and decided to put it off until this weekend to replace them. Well today I was on my way home and the truck started stuttering badly like multiple cylinders weren't firing, it then began to miss almost like it was running out of gas (I had half a tank so it I knew it wasn't), then it dies. I drift onto the shoulder and try and try to start it but it will NOT fire. I'll crank no problem, it just won't turn over. I assume at this point that I have a bad fuel pump, clogged filter, or bad injectors (although I checked them a few nights ago and they were both spraying). I guess it could be the distibutor or ignition coil too, but I have a feeling from the way it drove that it's fuel system related. Any suggestions? Anything I've missed?

 

I would start your troubleshooting from the beginning again. Check for fuel delivery again. If you got gas then check for spark. Pull out a spark plug from the engine, put it back in the plug wire, ground the plug to something metal on the engine (away from the cylinder where you pulled the plug from) and try starting the motor to see if your plug sparks. If you have fuel and spark, I would go back to the fuel system and test the fuel pressure (10-13 psi) to eliminate the fuel pump. well that's my 2 cents as to what I would do to start off with.

 

I would start looking at the fuel system. If it was an ignition fault it probably would have set ab OBD1 code for you. There is no way to set codes in the fuel system other than emissions stuff.

 

if it is not fuel, use a vacuum gauge to see if there is a smooth even pulse at the needle from 0 to 1 in Hg. if the needle is acting uneven then i would suspect it is something with the camshaft, possibly the timing chain. to confirm that i would do a compression test. all the pressure readings should be the same give or take a few pounds. if not the timing chain could be broken forcing the camshaft to be stuck in one position. these tools are fairly cheap to rent at autozone.

 

So I tried to start it with starter fluid and still couldn't get it to start so I checked and wasn't getting any spark. I replaced the rotor button and the ignition control module and it started right up no problem, but it's still missing at idle and when cruising at highway speeds (It doesn't do it so much as I'm accelerating). I was thinking at this point it's probably plugs and wires but thought I'd ask for a second opinion.

 

So move back toward the coil. The coil wire could have spark jumping from it, or a shoddy connection to power. I dont reccomend grabbing on it, but wait till dark, or get a friends help to hold it while you crank When spark is jumping out of the wires you can see it in the dark, and hear it snapping too. You should have gotten a new dist cap too, it could be cracked and expand in the heat so the rotor button missed the terminals sometimes when it spins.