I have a 93 blazer with the "W" engine and it ran fine for the first 3500 miles after having a problem which somehow worked itself out. Anyways, It starts and runs fine when it is cold and then after about 15 miles or so it starts cutting out. So I drop it out of overdrive and keep the RPM's up it will run til I slow down then it will quit.

Then after about 10 minutes it will start and run for a little while and start missing and or running rough. Then it will quit again. I checked the Fuel pressure and that is between 55 and 60 psi.

I have replaced the pump and sending unit, fuel filter, and FPR. The plugs, wires, rotor and cap only have 3500 miles on them. I tried a different Ignition Control Module, and a coil. It still runs the same. I hate to throw parts at something and not get anywhere.

I was looking at different posts, but I can't find the same issue. It almost seems to be an electrical issue of some sort. I don't know if a knock sensor will kill the engine after a while or if it is another issue.

I had a code for the fuel pump relay so i replaced that, no change. Then i had that code 43 so i cleared it and it hasn't come back on yet. Where would the knock sensor be on there? I have read left side of the head, under the distributor, just not sure. I would appreiciate any direction on this.. Thanks for your time.

~Kenny

 

Try cleaning the EGR valve....they are notorious for clogging up. It is located under the throttle body where the air intake hooks up.