92 s10 blazer (W) Problems

[117mph1999]

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.

[old_master]

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.

[exalteduser]

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?

[117mph1999]

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

[117mph1999]

Originally Posted by old_master

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.

[old_master]

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.