I have a '92 s10 Blazer with a 4.3 'W' vin code, (MPI). Its been a really great ride except when things decide to break down.
Current symptoms are, NO FUEL PRESSURE when testing on the fuel rail behind the intake manifold.
The original symptoms were skipping, backfiring, no power.
Parts replaced are:
Distributer assembly (Cap, rotor button, ICM, distributer)
Spark Plug Wires
Spark Plugs
IAC Valve
AC Delco Fuel pump
Fuel Filter
Spider Injector Assembly
Fuel lines (Connecting to the spider assy)

Am getting aggravated with backyard techs recommending their solutions, and all Im doing is spending more money in this dang 4.3 Vortec

PLEASE HELP!!!

 

Update. Never trust rented equipment from AutoZone, O'Reillys, or Advance Auto Parts. I rented a fuel pressure diagnostic kit from each....EACH ONE turned out to be defected. Renters of these...beware!
Upon further investigation, and verifying pressure at the fuel filter, I cleaned out the lines from the intake-to-the-filter with my air compressor, reconnected and still had the same problem of hesitation while accelerating. Time to check the electrical connections...again. Double-checking the replaced distributer assy.
Took the ICM down to AutoZone to test. It FAILED all 7 tests and was defective. Turns out when I bought the distributor from Cardone, the 'new' Ignition Control Module was bad. Replaced with a new one -remember the dielectric grease- and the problem was gone.
Total problem tied into a defective ICM.

 

Issue has come back! arrrghhh. Engine still sounds like its misfiring BAD and bogs down horribly when you accelerate. The darn thing will sit there and idle in Park or N, but will start hesitating and backfiring through intake when you start to accelerate.
Have replaced the Throttle Position Sensor, and MAP sensor too now. Have gotten a positive reading off a fuel pressure gauge. Getting 55 psi at idle, and 55-60 at higher rpms, even while its backfiring, and bucking.
Heard somewhere there might be a wire grounding out. I have already checked the harness, and it all appears fine!
Any suggestions what the issue might be???? SES light isn't on, so no codes