Hey folks,
I'm writing from Switzerland, sorry if you have trouble following this, but my first language is some sort of farmer Swiss-german slang.
I bought a 1996, 6 cylinder blazer with a 4.2 litre engine in february this year.
I bought it from a old man. When I got it it had only 115 000 km, automatic transmission rebuilt, brand new tires, oilchange, the whole 4x4 transmission rebuilt, new brakes front and rear, it's black and bold and beautiful. It has been running like a Swiss watch (apparently stands for great reliable swiss-craftmanship!?)
On this day 3 weeks ago when I was rolling towards an intersection, the engine shut off and hasn't been running since.
It took about 4 workdays (sorry to destroy a myth right now: o.k. guys - swiss people are "definitly not" reliable or productive at all!!!) to get it to my friend's garage. He is a 26 years old Turkish guy that used to work with vw und audi and has now his own garage. He is the coolest person ever: doesn't screw people over with unneccesery repair work or extra labor hours and always gives us awesome deals.
I like supporting honest people (sadly in today's day its hard to find this "breed") and don't care if it takes a bit longer than with official dealers.
Anyhow, enough rambling! The problem is that we have no idea what is wrong with it. We are trying to get some information on where the fuelpump relay is located. Don't have and can't get any books over here and the official chevrolet dealers don't give a flying monkey about me, or if you think ever of moving here, for any of you guys either.
We think it could be the fuelpump as well.
Have any of you guys had a break down like that? What could it be?
I am thankfull for any information because I don't want to have to spend 350 us dollars for a car diagnostic at a official dealer!
Thanx so much, Thomas

 

Hey Tom- Yeah I faced similar situation with my 95 Blazer 4.3L V-6 which is probably the same as what you have there. After alot of figuring I decided the fuel pump itself was bad. The fuel pump relay should be on the firewall behind the engine on passenger's side. (unless your car has the steering wheel on the right side of car which is backwards from us) But if you can turn the key on and hear a "whining" sound from under the car then the relay isn't the problem. If you don't hear anything it still could be the pump but the relay is a cheap first guess.
On my ride I could hear the whining sound but wasn't getting "enough" pressure out of the pump. The Vortec engine requires about 53 p.s.i. of fuel pressure to run correctly. If you look at the back side of the intake manifold right close to the firewall you should find a fuel pressure port (it looks like a threaded nipple with a tire valve in the center of it) You can screw a fuel pressure gauge on there to see if you have fuel pressure and how much. Of course you can also just turn key on for about 10 seconds then get out and press that center valve button and fuel should spray out rather quickly, so don't hold it down for long. That would tell you if the pump works at all but won't tell you if there is enough pressure without a gauge.
Well, that's at least a starting point. Good luck. Let me know how it works out.

 

Howdy,
I would like to add to what was posted above.
The relay moves around on the trucks, and really depends on year as to its location. The typical three locations that I know of are, 1) on the drivers front fender, 2) on the firewall (like mentioned above), 3) behind the glove box (look for an access panel inside the glove box).

There is also a hot wire that runs directly to the fuel pump and bypasses the realy. This can be found in the wiring bundle (look inside the wire loom, black thing full of wires) over the brake booster. The wire is red in color and doesn't connect to anything, at least that you can see. Run a wire from that to the battery, if the fuel pump works, replace the relay and or fuel pump fuse.

The fuel pump should push 58-60psi to start the truck, once running it should drop about 8-10psi. Use a fuel pressure gauge and test it like posted above.

There are a host of other posibilities, however since you asked about the fuel pump, that's what I replied to.

Post up what you find out. Plus post up other usefull information.
Does the engine crank over?
Are you getting spark?
Do you have lights on the dash?
Has your fuel gauge been acting up, does it work?
Did the engine miss, knock, rough idle, or any other symptoms when it still ran?
When was the last time it had a tune-up?
When was the last time you changed the fuel filter?