94 blazer no start!!!!!!!

help!! i have a 94 blazer, 4.3 "w" engine. about 6 months ago the blazer would shut off when sitting at alight or in traffic. happens with the a/c on and off. the engine shows no hint of stalling, stumbling or hesitation. shuts off like i turned the key off. and this happens after about an hour or more of driving. more or less the engine is fully warm. wait for a half hour to an hour and its starts with no problems. there are no engine codes. now i can't get to start at all. i checked all sensors, replaced everything in the distributor, injector was replaced a year ago, fuel pump and sender alitlle less then year. is there something i missed.

sometimes when i try to start it i use a timing gun to see if at least i am getting a spark, and i get nothing

i am unsure what a 1994 blazer has for ignition system so shower me with info. is it a vortex motor? you stated you replaced the spider injector assembly, is that true? if you give it a little throttle will it start? does it crank but not start at all? do you hear the fuel pump running in the tank? do u see the check engine light on in the cluster when the key is in on and the engine off? did you check your ignition module? what did you replaced in the distributor? what injector did you replace? what else did you replace?

its is a vortec. 4.3 c.p.i. the fuel pump and sender was replaced about a year ago. the spider injector was replaced 2 yrs. ago along with the egr. i replaced the module and pickup coil in the distributor. the problem i am having is that when it runs it shuts off when the vehicle is in a stand, waiting for a light or traffic., when the motor is fully warmed up. wait about a half hour and the vehicle starts again. i have no trouble codes but the check engine light does work. at the moment i can't get it started. i am not getting any spark.
i do have fuel pressure.

I have a similar problem in my 92 bravada. I also have fuel pressure but it will not spark. Let me know if you figure out what is wrong. I think mine might be the ign coil or module( both are sensitive to heat). Mine has what I would consider to be a weak intermittant spark. I bought mine from an impound yard so I don't know the history. Also, did you get a good coat of dielectric grease on the module when it was replaced? With out it, it could send one to its grave very fast.

i have seen many ignition modules and fuel injectors fail when they heat up only. the ignition module might be shutting down when the temp gets to high. msclcrmn is right make sure you have the dielectric grease on the ignition module as that might be your overheating problem.

See my reply on code 42 ESC, never know?

Also, this is the tell tale sign of a overheating coil going kaput.

Replace the coil.