Hi guy's, i am having a bit of trouble with my 2001 blazer , it has the 4.3 vortec engine..... i'll start from the beginning i was on my way home the other day.. on the high way doing about 70mph . it just all of a sudden died i pulled it to the shoulder and tried to re-start it but all it would do is roll over but not fire..so i had it towed home . i know these thing's are famouse for fuel pump's going out so that was the first thing i checked.... turned key , i could hear it energize , but it still would just turn over and not start. so i tried putting a little gas down the throttle body, it still would just roll over and wouldn't even attempt to fire. so my next thought was spark...i took the coil wire off the distributor and hooked my 12V test light to it to see if it would flash when i cranked it over .i didn't get anything. so i replaced the ICM, that didn't help , replaced the coil...that didn't help either. the truck ran fine no problems at all no missing or popping. i did notice a slight surge or hesitation before it died , but it didn't reflect in the tachometer. so i am looking for any suggestions this is our only vehichle and need it to get to work ,HELP!!!! im pulling what hair i have left out!

 

You can't test your coil with a 12 volt test light. The best thing to do is check for spark at the plugs, that will let you know if the coil and the rest of the ignition is working. The way I like to do it is pull off one of the plug wires, stick the end of the wire on a spark plug, and lay the metal part of the plug on a metal part of the engine, make sure the metal is making good contact. Crank the engine and see if the plug fires. If it does you ignition system is probably working ok..I check the coil the same way. Don't hold the plug, or the wires.

If you have spark at the plugs come back and we'll go from there.

 

ok i tried checking for spark the way you said it rolled over about 6 time's before the battery died, but there was no spark ( battery to weak?)

 

Check your ECM....see it it will respond...hopefully it will give you some codes.....if nothing, then it probably died.

 

how do i check the ECM ?

 

1st thing to do is FULLY charge your battery. Next, check your fuel pressure, go buy a gauge for this if you don't have one, they're not expensive. If you have 60 psi or greater, then check your spark. After checking those things, come back and let us know what you found.

 

ok i'll try that , but i have the stopping at a friends to pick up the charger and she wont be home until 11:30 pm so if i don't get to it tonight i will on it first thing in the morning... does it have to be running to check the fuel pressure?

 

i have about 65 psi at the fuel rail . now i just have to wait for the charger so i can check the spark.

 

Symptoms of a Bad Crankshaft Position Sensor: Possible Causes & Fixes check into that poss being the problem...

 

up-date ...charged battery tried to start it, it would roll over but no spark...had battery charger hooked up when i tried to start it ...had setting on engine assist...i noticed it drew alot of amps and the battery dropped down to 25% ...could it be i need a new battery? would this create the no spark situation?