94 S-10 Blazer 4.3 W

[Golfofun]

Runs fine in neutral but put it in drive, go half mile and cuts out. Won't restart immediately but after five or ten minutes it starts up, maybe runs, maybe dies quickly. Help!! Tuned it up,wires,plugs,filter (gas and air),pcv,dist cap,rotor,ignition control module.

[BlazerBoyLT98]

Catalytic converter maybe???

[riptide44]

so you replaced the ignition module on the distributor right ? and it still does it ? did you you use a new part or used ? still could have got a bad new one . there is also a pickup coil inside the dist. requires pulling the dizzy and basically a rebuild - the part is only 10 bucks - also the while the dist. is out check and see if the magnet is still welded to the distributor shaft or does it spin around with a little force ( happens on a few of these ) at this point you can also see if it is still magnetized - by turing the shaft and letting it go and see if it stops in each firing position.

[Silverdragon12384]

I have a 94 S15 Jimmy with the Famous 4.3 W and i was having problems driving it down that rough with full tank or not it would want to stumble around and jerk and basically acting like it was running out of gas. I had that sending unit replace with new and the starter is new, as well as the dist.Cap and rotor. This engine has carbed up on me alot so i took the EGR valve off and cleaned it. The truck started after i did all of that but did not run right. My Problem now is I changed that oil and was looking to see if maybe I had a cracked head on it but that oil was fine. I did drain all that oil and was messing around it later in that day and forgot about that oil and for a second tryed to start it could that of cracked that head on it. I Tryed to start it and then it clunked around and then i let go of that key, but is never started. I put new oil in Cleaned up that dis. cap put everything back together AND now it will not start at all. What could be that problem????

[riptide44]

silverdragon..... it could be that the oil pressure switch sensed no oil and did its job of shutting down the fuel pump to prevent siezing the motor -- give it a few tries and if it wont start disconnect the battery for 10 minutes then reconnect and try again --- however is the oil pressure switch still working ? does the guage register when you crank ? then again you could be a victim of circumstance and the cpi unit is shot ( very common ) but you need to check that with a fuel presure guage . key on engine off should be around 60psi if it hits zero real quick - theres a leak in the system -- let me know what you find pressure wise and post back . by the way it might take a bit of cranking over to get the pump to run - oil switch needs to see 4 psi before the pump will run again .

another item, would be the ignition module on the dist.

i realise im throwing out a bunch of things but they are the most common .

[Master.ASE]

check fuel pressure, then oil pressure while cranking. recheck cap. they are tricky on a blazer w engine. you didnt crack a head. these motors are like tanks and go over 300,000 all day long without any internall work. what was your clunk and why did you tune it up, any systems befor tune up