Fuel delivery woes

[taijiguy]

Specs: 99 LE 4x4 4Door, 3.4, loaded.

Drove the thing to work yesterday, truck drove fine. Parked it, came back out about 3 and turned the key, it wouldn't fire. Turns over great, but won't run. Gave it a blast of starter fluid, it fired but of course immediately stalled. Other symptoms:

All dash lights appear to be working, looks like power distribution is OK. When I turn the key "on", I don't hear the fuel pump priming. If I take the key to run, then back to on, the fuel pump runs for a couple of seconds, and shuts off. I checked for fuel at the Schrader valve, and had some pressure, but I don't have a guage, so I can't say how much, doesn't look like *alot* though.

Any help is greatly appreciated.

~Taiji

[modification_inc]

When The Fuel Pump Dosnt Turn On Can You Hear Any Clicks From Relays ?

[taijiguy]

Originally Posted by modification_inc

When The Fuel Pump Dosnt Turn On Can You Hear Any Clicks From Relays ?

Well, I hear a couple of relays, but I'm not certain which are actually the pump relays. So I can't say for certain if it's the *right* relays that are kicking in.

[RABarrett]

Something to remember here gentlemen is that if the relay does not power the fuel pump, the oil pressure should. If, after oil pressure develops, there is still no fuel pressure, voltage, ground, and pump issues are likely. Ray

[taijiguy]

Originally Posted by RABarrett

Something to remember here gentlemen is that if the relay does not power the fuel pump, the oil pressure should. If, after oil pressure develops, there is still no fuel pressure, voltage, ground, and pump issues are likely. Ray

It won't start, so oil pressure never comes up. I've shot starter fluid in there, but it only runs a second. I can't say if the pump runs during that short time or not. I'm leaning towards the pump as the problem. But I'm not happy about it...at 300 buh for the pump.

[blazer01]

I had a similar problem with my 01 blazer. it would run fine and then after sitting for a few hours after being driven for an hour or so wouldn't start. it had power like you said but it just wouldn't start. but then the next day it would start right up. It turned out to be the fuel pump. sounds similar so I would definately check the fuel pump. I had posted a link on there asking for help about a month ago so you can check it out and see how simiar it is. it is under blazer01 and trouble starting I believe.

[supervious]

I have a 01 blazer, 4.3 (not a Vortec) checked relays,and grounds. Inspected fuel pump and replaced fuel pump It worked but had a tore screen. The only way it will run is if I put 12v to the test wire on the firewall. I just put a full tune-up on it about three days before. I drove to the store, came out and it wouldn't start.

[supervious]

Fuel problems....I have 12v at only one of the relays when the key is on, but pump or relay make no sounds.

[RABarrett]

Again, oil pressure is sufficient to operate the pump at cranking. If the engine does not operate the pump, even with extended cranking, the pump or voltage or ground is likely the issue. Ray

[RABarrett]

P.S. If applying voltage to the test terminal makes the engine run, the issue is likely a relay or control issue. Cranking oil pressure will also apply battery voltage to this circuit. It is possible for the switch powering the pump is damaged, causing parallel issues. Ray

[supervious]

When you say control issue, what are you reffering to? I borrowed relays from a functioning blazer same year, and it made no difference. Is there a way to jump out the oil pressure switch, or a spec on the readings I should have for testing.