92 s10 blazer (W) Problems

For about two months my blazer was really hard to start and sometimes it would start right away even when cold but not a lot. About a week ago it start to stumble and what sounded like missing, a lot during acceleration so I quit driving it completely. Then I had to go stay with my girlfriend for a couple weeks so I decided to chance it and drive it over there so I could continue working on it. Got about 15 miles down the road and just died, and I have not been able to get it to start since. I was just pulling away from an intersection when it happened so was at a dead stop. Haven't seen any noticeable drop in fuel economy but it does seem like it was lacking a small amount of power during the time before it started stumbling. Haven't performed any tests yet but plan to do a fuel pressure test and possibly remove the upper plenum and check out the regulator and such.
I've replaced the sending unit and fuel pump, o2 sensor, fuel filter, cap and rotor and plugs.
Noticed the other day that the metal tips where the wire plugs into the spark plug is already rusty after only being on there for maybe 6 months and yes they are AC Delco.
Any ideas and let me know if you need further info.

If you squirt a shot of carb cleaner in the air intake will it start?

As for the rust.... when replacing plugs and/or plug wires, always put a dab of silicone dielectric grease in the plug boots, (both ends). It prevents rust by keeping moisture out, makes the boot easier to remove next time, and helps with the electrical connection. When replacing the distributor cap, put a dab on each terminal of the cap, inside and out.

Tried spraying starting fluid in the intake but no start at all.

Pull the coil wire out of the distributor cap, prop it up about a half inch from ground, (don't hold it) and crank the engine.... is there a good blue, not orange, spark?

I had this problem with a '93. Mine died when it was hot and basically would not start again. It turned out to be the Module in the Distributor. Before you pull everything apart, TEST. The Module can be bench checked at AutoZone.

Got a blue spark.

Ok, that's good! Plug the coil back in and check for good blue spark at each plug.

Forgot to add that I took off the distributor cap and there was build up on the inside part of the terminals as well as on the rotor tip. So I just picked up a new cap.

The "build up" is supposed to be there. When the cap and rotor are replaced, there should be a dab of silicone dielectric grease added to each terminal, inside and out, of the cap, (it helps conduct the current). When the engine is running, the current passing from the rotor to the cap causes the grease to crystalize.

Have you checked the fuel pressure yet? Can you hear the fuel pump 2 second prime cycle when you turn the key on? Stand by the gas cap door and have someone turn the key on and listen for it. When was the last time you changed your fuel filter?

Changed my fuel filter about 9 months ago. Checked fuel pressure and it was at 59psi. Since I've owned it it has always had a leak down problem which never seemed to prevent it from starting, unless it has become worse now but didn't look like it went down any faster and this last test I did. Checked everything underneath the plenum and it doesn't appear to be leaking in there. Yea I can hear the priming when the key is turned on.

Pressure is fine for 92 CMFI. Provided the pressure remains above 53psi for 5 minutes after the pump shuts off, it should be fine as well.

Forgot to mention that when I took off the upper plenum it was oil covered everywhere inside. And there was a 2 or 3 areas where it had a few drops of oil that had pooled. Could this have anything to do with my problem. Took some pictures when i removed the plenum.

i dunno for sure, but i'd say that's normal, especially for the age. i did the lower intake gasket on my '01 last year and the manifold/plenum were caked with carbon/oil buildup.

Normal, although there does appears to be slight "washing" near the fuel pressure regulator. A fuel pressure and leakdown test would tell for sure if it's leaking fuel.

I ran one when i first got the truck, and it had a pressure problem then I replaced it with a fuel pump a friend had on his blazer that was just sitting around cause he had a newer one and that seemed to fix the problem it was having at the time. Ran one after I put the pump in and noticed it was still not holding pressure longer then maybe a couple seconds. I checked all lines go to and from the engine and none were leaking. Or maybe the pump I put in was bad from the start from sitting for awhile or it was the regulator the whole time causing the leak. Can anything else cause there to be "washing" around the regulator besides a leak from it? When I had the plenum off I cycled the key on and off to see if there was a leak coming from anywhere and i didnt see any signs.

If there are no external leaks from the tank to the back of the plenum, and no visible leaks inside the plenum, there are only three things left: The check valve in the fuel pump, the flex line from the pump to the module, (gotta remove the tank if either one leaks) and a leaking fuel injector. The only way to determine if it's in the tank or in the plenum, is to install a shut off valve, either temporary or permanant, in the fuel pressure line near the fuel filter. Then allow the pump to pressurize the system and immediately shut the valve off. If pressure drops, the leak is in the plenum. If it holds, the leak is in the fuel tank. It is possible for the fuel pressure regulator to leak internally past the valve and seat.

when i had leakdown(the nut kit) the excess gas would drain thru a little hole in the plenum, and eventually my oil started to smell like gas.

also, was there any codes thrown?

No codes are pretty sure the check engine light works, it turns on for a few seconds after starting.

If there are no external leaks from the tank to the back of the plenum, and no visible leaks inside the plenum, there are only three things left: The check valve in the fuel pump, the flex line from the pump to the module, (gotta remove the tank if either one leaks) and a leaking fuel injector. The only way to determine if it's in the tank or in the plenum, is to install a shut off valve, either temporary or permanant, in the fuel pressure line near the fuel filter. Then allow the pump to pressurize the system and immediately shut the valve off. If pressure drops, the leak is in the plenum. If it holds, the leak is in the fuel tank. It is possible for the fuel pressure regulator to leak internally past the valve and seat.

Sounds like I will need to put a shut off valve in. Is the check valve something I can replace or do I need a new pump.

The check valve is part of the fuel pump and is serviced only by replacing the fuel pump. The pump is rather expensive, so make sure that's the problem before replacing it.