I have a 1995 Chevy Blazer 4x4 with the 4.3l vortec engine. I replaced the starter on it last fall as it was spinning and would take several tries to actually start. After replacing the starter, the truck ran fine for one day but then would not start the next day. It would crank but not turn over. After that I replaced several parts:

-Fuel pump
-Fuel filter
-ICM
-Ignition coil
-Distributor cap and rotor
-Cam sensor
-Spark plugs

It is getting fuel and spark so I am not sure what the problem could be. It will just crank but not turn over, it wont sputter or anything like that. My next idea is replacing the fuel pressure regulator but I am not sure. Any help would be appreciated. Thank you in advance

 

First step is fuel pressure leak down testing as in the sticky. You must maintain >55 psi at ten min.

Check for spark on a couple of plug wires, both banks. Is the spark strong (1" gap) and regular?

If both of those things are good then you need to test for fuel injector pulses with a noid light.

Are you sure that your gas is clean and fresh?

George

 

I tested the fuel pressure. It goes up to about 50psi when i turn the key but then drops right away to about 15psi

 

Next step is to determine fuel tank or intake.

George

 

So do I need to hook the fuel pressure gauge up to the filter to see if it is the pump that is bad? Thanks for your help george I appreciate it.

Also forgot to mention that the fuel pressure regulator was replaced 2 weeks ago, so hopefully that is not the problem.

 

Yes, test initial pressure and leak down at the filter. That regulator is not a verified repair yet so it’s still a suspect.


George

 

I replaced the whole fuel pump housing and it is now getting enough fuel pressure.
But now when I try to turn the key, the truck loses all power. The lights dim and the battery gauge goes down to 0. I still can hear the fuel pump running and the other electronics work. I charged the battery and cleaned the terminals and ground but still have the same problem. I tried to start it with my booster pack as well but no luck.
I'm wondering where I should go next. Should I try to test my starter with a voltmeter? Or is it possible that the new fuel pump is drawing too much power?

 

1. What is the battery resting voltage (at the terminals) with everything off?
2. Same question at key on
3. Same question in the start position

George

 

Hi George, I just tested it and got these numbers:

Resting: 12.5
Key on: 12.26
Cranking: 6.18

 

How old is that battery? Assuming that the connections are clean and tight at the battery terminals it’s acting like it’s failing. If it’s more than 3 years old you should consider replacing it. If you would rather be sure you can have it load tested first. There is an outside chance that the starter is bad but load testing the battery would confirm which it is.

George