ok, here's the low down.... 1996 S-10 chevy blazer, 4.3 V6 vortec, the other night I left my house, got maybe a 1/4 mile and the engine died. Tried to crank but will not start. Got it towed back to the house and checked spark, disconnected coil pack wire and get spark while trying to start, depressed fuel valve to the back right of engine and some fuel will come out. Fuel pump was replaced about a year ago. I removed the aire intake to expose the throttle body and while I try to crank I get what I am guessing is a back fire, sounds like a vacuum thing but I see a little bit of flame coming from the throttle body. Now I'm not a mechanic but I think it might have something to do with the spider or plenum (sp?). I have no clue why this darn thing won't start. Please help!

How many miles on this engine.It sounds like you might need to do a timing belt.

80k.....is there a timing belt on this year/model? or is it a timing chain? if its a chain, possible that it could have broke? or something else happened to it?

thanks

Im not sure if it's a chain or a belt on the 96 but chances are good that the truck either jumped timing or the belt or chain broke.It seems like you checked spark and fuel and that was good.A backfire usually means that there is a detonation of built up fuel.I would definately replace the timing chain or belt because you could possibly cause engine damage if you keep turning it over and the belt has skipped from being stretched or if it broke.At 80k miles you should be due for a belt change anyway.Just make sure you bring the #1 cylinder up to TDC manually and line up the timing marks when you insert the new gears.

when exactly is the timing chain supposed to be replaced?

Find a timing light and check timing while cranking the engine. Should be in the ballpark if the chain is ok. They usually last forever in the Blazers. Any chance of moisture in the dist. cap? Pull it off and check the inside for water, dirt, corrosion on the terminals. Take a close look at rotor button too. Clean everything up anyway and wipe coil off real well. These things throw very high voltage and will cross fire if not just right. With upper intake off you might turn on key and look for any fuel spraying from the internal fuel lines, real common on the Vortecs. Be a very,very fine mist. Could be time for a new CPI unit too, but they usually give warning before going bad. Good luck with this.

ok, here's the low down.... 1996 S-10 chevy blazer, 4.3 V6 vortec, the other night I left my house, got maybe a 1/4 mile and the engine died. Tried to crank but will not start. Got it towed back to the house and checked spark, disconnected coil pack wire and get spark while trying to start, depressed fuel valve to the back right of engine and some fuel will come out. Fuel pump was replaced about a year ago. I removed the aire intake to expose the throttle body and while I try to crank I get what I am guessing is a back fire, sounds like a vacuum thing but I see a little bit of flame coming from the throttle body. Now I'm not a mechanic but I think it might have something to do with the spider or plenum (sp?). I have no clue why this darn thing won't start. Please help!

Does the fuel pump turn on when the key is turned on?

How many miles on this engine.It sounds like you might need to do a timing belt.
:twak: