Id start by diagnosing the fuel system.
96+ Fuel System Diagnosis - Blazer Forum - Chevy Blazer Forums

Do a leak down too. Have you changed your fuel filter? when did you do this?

 

Yes i have. Changed everything 5 days ago.

 

I had a similar sounding problem and it ended up being the pigtail that plugs into the spider injector through the plenum.

 

This also sounds like a problem I had in the past. Took me forever to find the problem. It ended up being a bad ground wire to the fuel pump. Replaced ground wire and no more problem. I think that was a 87 or 89 Blazer.

 

I am having a very similar issue with a 2000 blazer. thanks for the tips on what to change.

 

in my opion u have changed to much. u need to do the testing instead of threwing parts on it. u could be wasting money and time. search on here to help urself. did u use ac delco on ur parts? this trucks are very finicky.

 

My check engine light does not come on so no one will tell me what it really is. If i reset the computer by unhooking the positive from my battery and turning the key, hooking it back up, it starts no problem. It acted up last night, not after gas but almost seemed like the battery was dead. Had it tested this morning and it's fine.

 

These trucks have OBD 1 or 1.5 the check engine light typically only comes on for major failures usually in the sensor department. The fuel delivery system is completely unmonitored. I would recommend checking your grounds and connections. When I replaced my fuel pump and sender (for the second time in 3 months because I didn't use a AC Delco the first time) I ended up hard wiring the pump because the harness was giving me an intermittent connection so the pump would briefly shut off going over bumps and my fuel gauge wasn't working. Also the computer fires the spider injector by pulsing the ground connection, if the resistance in the connection is too high or nonexistent it won't work.

 

Ive had my blazer at a mechaic for the last week. He says the fuel lines are all messed up underneath the car meaning whoever had it before me hooked everything up wrong. Also says that theres supposed to be a charcoal canister, that has been bypassed. Any way i could find a correct diagram of the proper hook up?

 

Did you check ground wire to the fuel pump? The reason I ask is I had a Blazer once that had a bad ground wire. When I replaced it I quit checking, and no more problems after that.