To anyone to can help. I have a 2000 chevy Blazer 4x4 that all broke down on a highway it was sputering then stopped. The engine cranks but will not turn over. I check and made sure I am getting spark on my plugs, but it seems I am not getting any fuel pressure. I tested the voltage at the fuel pump relay and I am not getting the 2 second 12 volt prime I need for the pump. I took out the fuel pump relay and I am not seeing any votage coming from the PCM at all, on any of the wires. Is there anything that could be bad that will cause the PCM to stop giving power. I am thinking the PCM is bad but hopeing its something else as this PCM need to be calibrated by a dealer and I really don't want to spend the money on this if I don't have to.
Its a CMF injector engine.
The PCM fuses are good, I also replaced the fuel pressure regulator.
The engine does crank so could the issue be the ignition switch if so how do I test it?

Any help will be great


Thanks,

JC

 

In the underhood fuse panel, if you apply battery voltage to the pump prime terminal, does the fuel pump activate?

 

Ran a line from the battery right to pump pro
E connector. Pump still not turning on.

 

Sorry my spell check can spell

I ran a line from the battery right to the pump prime connector and pump did not come on.

 

Just to make sure you will need a volt meter at the pump. With someone turning the key to the on position make sure you have 12v for about two seconds to a good ground, this is from your trucks wiring. Then switch the meter to ohms and put the lead on the trucks ground wire at the pump and to a good ground. It should read 5 ohms or less.
If yes to both questions you have a bad pump.

 

I'm not seeing the 12V for 2 seconds at the pumps connectors. I don't see the 12v even at the fuse panel when turning the key to the on position. I would think its the PCM but I can't get the pump to turn on even when I jump the 12v in the relay right to the fuel prime connector. I think the pump is shot, but why am I not getting the 12v prime volts from the PCM.?

Thanks for the help.

 

In the underhood fuse panel, the ECM B fuse must have battery voltage on both terminals of the fuse at all times, (do not remove the fuse, check voltage on both terminals on the top of the fuse). Post your results.

 

I check ed teh fuse and it was getting power so I decided to replace teh fule pump anyway since the direct 12 volts would not let it kick on. after replacing the fule pump I tried to start the engine. It cranked for a few seconds stopped, now I can't get it to even turn over. It seems like the starter it not working. is there a way to test my starter after I try to get is out before sinking more money into the repair of this? Also, could it be my flywheel that is seized to turning? when I turn the key the panle lights all start to drain down. I hooked up jumper cables to another car and let it charge the battary for a bit and still the same results the belt or fan don't turn. after I replaced the fuel pump I did hear a loud clank then trying to turn it over.

Thanks for all the help Captin Hook.

 

You jumped to conclussions before the diagnosis was complete, and it cost you some bucks

With this new information about the starter, we need to change direction and diagnose that issue first. BEFORE you pull the starter:
Check voltage at the battery terminals.
Check voltage at the purple wire on the starter solenoid while attempting to start the engine.

Post the results of both tests.

 

Had the change the fuel pump, after changing it out i can now hear the pump turn on when i turn ignition on.

I have 12.5 volts at my battary terminal. I cant get to the starters purple cable unless i take out the starter. When i crank the engine i can hear the relay clicking when i remove the relay and put a jumper from the 12v i get on the top right connector(30) to the bottom left connector the starter just hummes and it looks like its trying to turn over but cant like it jammed or not getting the amps? If i unmount the starter it spins, not sure if i checking it right but when disconnected from the flywheel i connect my pos+ line on the volt meter to the purple cable and the Neg- to a good ground i only see .2 volts. Should i test it with the starter completely removed? Not sure but in my research i found it could be the iginition switch or nutrel safety switch, any thoughts?

Thanks
JC