Hi all, I'm working to a friend’s 2000 Chevy Blazer 4 door and could use some help.
The car just died while driving down the road. Still cranks strong, but no start.
I figured fuel pump, So, I pulled the pump tested it (dead) and then replace it.
Buttoned everything up and went to start it, still a no go. I can hear the pump running,
I check at the fuel bleeder valve by the throttle body for pressure, their was
I then checked for spark at the coil, and their was a strong spark. Open the throttlebody blade and I can't smell a strong fuel smell even after cranking on it and trying to give it gas multiple times. So, I was figuring injectors or computer.
The engine light is not on so I have no codes off of.

Any help or tips on things to check or other common problems on Blazers that I can check, would make me grateful to say the least as she need her can running and I want to fix it .

Cheers, JR

 

did you actually put a fuel pressure gauge on it to see the exact psi as these vehicle are super finicky as to the fuel pressure they need to fire thru the injectors! jp ps if there is enough pressure-54-60 key on then mid 50's running. Shut off...does it hold? Let us know-we'll all do the best we can to help![>:]

 

I agree with Peru. Mine wouldn't start and it turned out to be the Fuel pressure Regulator. Good luck!

 

I will check what the fuel pressure is tomorrow but i do have one more question.
Is the fuel system in a open loop? you can hear the pump going and going when the key is just in the on position. I'm use to fuel pumps priming up to the right fuel pressure when the key is in the on position then stopping till they are needed. But this pump goes and goes and goes. I just ask because if they do shut off after they prime up then that probably means I got a line mixed up and its pumping itself right back in to the tank and the return line in going to the motor (pressure but not enough). Let me know what you think. I just find it funny that the fuel pump and fuel regulator would go out at the same time.

Please let me know and thanks, JR

 

The fuel pump should only run for a few seconds, then shut off.

The fuel system pressure is regulated by the fuel pressure regulator which bleeds pressure off to a return line that goes back to the tank.

When the key first goes to the ON position, the PCM commands the pump on for a few seconds, then shuts it off. You may have a faulty fuel pump relay.

 

It might be a faulty relay but that still doesn’t explain why the car won’t start. Even if the pump is running constantly that means it should have enough fuel pressure to start at lest. Is their only one fuel pump relay? I checked the one in the main fuse box under the hood. Is their another one the computer controls?

Thanks, JR

 

Did you actually check the pressure? If not, start there.

Will it start using starter fluid through the throttle body?

If you have the intake duct work off of the top of the throttle body, disconnect the MAF sensor electrical connection or else it will not run.

 

OK I'm still shooting in the dark here.
I got the fuel pump to cycle (a FEW times) when you move the key to "on" but, it's intermitant.
All I did today was walk up to the car put a new relay in and went to start it.
Put the key in the on position the fuel pump cycled for 3 sec or so, went to start it
still a no go and the pump dosen't sound like its running, When tring to start it.
the pump also cycles sometime went I turn the key off.
But most of the time the pump won't cycle at all.
I can jump the "relay points" with a wire and make the pump run just fine and conctent, so a broken wire dosn't seem likly.
I also checked, at the relay, the power for the pump and power for the relay when trying to start it, The power dosn't cut out on either of them at any time. ruling out the ignition switch.

I'm at my wits end here.
Any body have a clue?
The computer seems like it fits all the problems.

If someone can tell me if you move the key to "on" then "off" then back "on" dose the pump cycle everytime you do it?

And How the hell can I get into the damn fuse box, I was trying to open it up the look at the wires, but could get anywhere with it gently. lol

Thanks, JR

 

the pump will NOT cycle every time the truck is keyed on. It requires a 10 secondish period between keys on and off. JP by the way-what brand of pump did you buy?????