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Mark, ASE Certified Technician
Category: Chevy
Satisfied Customers: 847
Experience:  34+ yrs Dealership Exp. - Fully State & ASE Certified - GM Master & GM World Class Tech
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1995 Chevy Blazer: LT..4.3L..a day or more,then it wont start..agian

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I have a 1995 Chevy Blazer LT w/4.3L Vortec engine.Sometimes it will start for a day or more,then it won't start for a day and a half or more,then it will start agian for a day or more and so-on.Sometimes it will start and run for a few seconds and die.I've changed the cap & rotor,fuel filter,fuel pump relay and fuses(none were blown).I'm at a loss as to what could be wrong with it.Can you give me some suggestions or solutions.

Greetings, my name is Mark.

Could be a couple things going on here. Need just a little info.

Have you ever been driving the vehicle, and when you come up to an intersection it will stall? You start it back up and you maybe have to keep your foot in the gas to keep it going.

Does it run rough sometimes?
Customer: replied 7 years ago.

Hi Mark nice to meet you,

No,I haven't had any of those problems(yet)and when it runs it runs smooth.

........and hello back to you.

I was thinking possibly you might have a stuck EGR valve. These things were known to get carbon up in the valve and hold it partially open. The vehicle would run rough and sometimes stall.

I wish we had a scanner to hook up and see what the block learn integrator was doing. You have a "spider" fuel injector set-up underneath that fancy intake manifold. These are notorious to leak and the engine will run extremely rich. In most cases, your oil will become diluted.

From what you are telling me, even though you changed the fuel pump relay, I am thinking the fuel pump itself is failing. Don't see too many fuel pumps that fail once they start the vehicle. It is usually only after a sit. Most likely there's a dead spot in the armature of the motor.

One way we confirm it at the shop is to get the vehicle to act up. Crank the engine and verify the "no-start". Then take a rubber mallet hammer and beat on the bottom of the fuel tank. Then try and start the vehicle. By tapping on the fuel tank, you're jiggling the pump a little bit and moving the armature.

That is what I think is happening when you have your "no-start" and then "start". Opening and closing the doors. Getting in and out of the truck. etc.....

You can put a fuel pressure gauge on the vehicle and you should have at least 55 psi. Then, leaving the gauge on, turning the key off, the gauge shouldn't drop.

Hope this helps shed a little light on your issue......

Mark and 10 other Chevy Specialists are ready to help you
Customer: replied 7 years ago.
There aren't any other relays or something of the sort that could be doing this?
Customer: replied 7 years ago.
I was just wondering if there could be another relay or switch that could be causing the problem?Not that I wasn't already thinking of the fuel pump.
Not really.

The only other thing that is related to the fuel system is the oil pressure switch. If the PCM (computer) doesn't see oil pressure, it won't turn on the fuel pump.

I don't know if your vehicle has an oil pressure gauge or not. When cranking, see if the oil pressure is coming up. The switch is down underneath the distributor cap.

You might want to look see down there and see if it's leaking. AND, if you do go there, be very careful when replacing. It is screwed into a 90 degree brass adapter. They are very easy to break.. Use care IF you're thinking about replacing.