I am having problems with my 93 s10 blazer full size. I had the fuel pump replaced by a mechanic along with the fuel filter, dist. cap and rotor. the next day it started stalling out agian so i replaced the coil pack, pick up module along with new plugs and wires. My dist. cap is off my one the mechanic said he fixed that and it ran perfect for from thursday until this after noon. i am stuck i dont know what it can be it starts right up and runs for about 5 mins and then starts to struggle then dies. it will start back up but then go right out again. once and a while it will start up and run for about 30 to 40 mins then go out. PLEASE HELP could it be the egr valve or a o2 sensor. the mechanic says he cant find anything wrong the fuel pressure is he said is at 60psi last time i had it in the shop. i cant keep affording to pay him to look at it everytime and he not give me a answer on what the problem is. i know how to do the work myself. he puts it on the computer and he says everything checks out fine not error codes and i cant seem to get my hands on a obd tester for my truck autzone, o'reillys, and advance auto cant do a test on anything older then a 96' so again please help i am lost without a cause

 

There is a paper clip method to check the OBD1 check engine lights, thats if the truck is throwing codes. check link and read every thing at the top and then check what engine you have, most likely 4.3L Vin "W" but check the vin # on the dash to see if there is a W or Z. Then check the code and then we can see from there. Oh and a small strand of speaker wire i think works the best but a paper clip will work most of the time.

http://www.troublecodes.net/GM/

 

i will try that tonight and see. it is a 4.3 cpi vin#w. the service engine light came on once a few weeks back but never came on again. the mechanic says its not. i am going to check that out tonight when i kid goes to bed and see if its throughing codes

 

make sure your alt is working
wounds crazy but i had the same problems with my 94 tbi i have in my toyota.
changed the alt and it fixed everything

 

yeah my alt is putting out the correct voltage and holding the the charge ..

 

you can scan it yourself if your check engine light is on. which it prolly is

OBD1 Codes "How to pull with code list" - Truck Forums

 

I had the same trouble with my 93 4.3 w and it was the wire connector from the injector(spider) not making good connection.