1995 Blazer Problems

I have another problem with my 95 Blazer. It would sputter hard, I would shut it off, start it back up and it would run fine for a while. The more that it cooled down the longer it would run. I have gone through and replaced the Distributor Cap, Rotor, Spark Plugs, Wires, Fuel Filter and have just replaced the Fuel Pump.

With just replacing the Fuel Pump, the truck ran rough in idle but when taking it down the road it would seem to run fine. I took it around the block, parked it and checked the EGR Valve and the Clean Screen, clean a little coal from the screen and the EGR was not stuck at all. I put the EGR Valve back in and it would not start. Any chance it could be the Timing Chain???

While it was running after the fuel pump was installed: The Service Engine Soon Light was blinking for a while before it stayed on.

You've been into several things...we need to diagnose it rather than throw parts at it.
How many miles on the engine?
What brand and part number of parts have you installed?
What DTC's (diagnostic trouble codes) were retrieved?
SES light blinking usually indicates a misfire.
(these engines are fussy when it comes to ignition parts)
Did you check fuel pressure and leakdown?
Easy enough to check timing chain but need to know what system you have.
(late 95 some were equipped with CSFI) Do the fuel lines go vertically into the top of the plenum, or do they enter in the rear of the intake manifold?

Spark Plugs - AC Delco, Wires - Bosch, Fuel Pump - Bosch, Fuel Filter, Distributor Cap and Rotor were purchased and installed by a shop. The engine has about 160,000 miles. Before installing the fuel pump the fuel would jump down to about 26lbs. after driving for a little while. You can smell the gas in the engine a lot now when tring to fire it up. Not sure about the CSFI? There are 3 lines that go to the tank and then run the drivers side up to the engine. The SES light hasn't come on the whole time we have worked on it until we replace the fuel pump.

Most likely a CMFI system... Check fuel pressure and leakdown: Key on, engine off, fuel pump running: Pressure must be 58psi to 64psi and must remain above 53psi for 3 to 5 minutes after the fuel pump shuts off. There are several things inside the plenum that can leak fuel...when there's a leak, the excess fuel goes straight to the oil pan through drain holes in the intake manifold. It will dilute the oil and greatly reduce its lubricating abilities. As a result it will destroy main bearings, rod bearings, camshaft bearings etc etc. Check it out and post back your readings.

Thank you for the help old_master. It may take a while to do a fuel pressure test, with it not running I am unable to get it to a shop and I don't have a gauge. I am trying to fully understand, does "plenum" mean the intake manifold? Do you have any idea what might have to be changed so I can start looking for parts?

The plenum is the upper intake manifold, it must be removed to access the injector, fuel pressure regulator, nut kit, (fuel pressure line to the injector and return line from the pressure regulator) and the lines & poppets to the intake ports. If you remove the plenum and turn the key to the RUN position, don't start the engine, you'll probably see what's leaking. Normally it's covered with black carbon deposits from the EGR valve doing its job. If something is leaking fuel in the plenum, it will be "washed" clean. In this picture the regulator has been leaking, and possibly the "nut kit" as well.

http://i561.photobucket.com/albums/ss58/cwhook/LowerIntakeManifold.jpg