Starting problems - not fuel cutoff, not theft light
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Joined: Jan 2012
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Starting problems - not fuel cutoff, not theft light
I have a 2003 5.4L that I bought about 3 months ago. About a month ago, I couldn't get it to start. It cranks very strong and the engine turns over, but it just wont start. I have tried everything I could find on the forum - tried the fuel cutoff switch, but that didn't fix it. It's not throwing any codes. The theft light doesn't blink when I have the in the ignition. I've tried both of my keys.
The first time this happened, I kept trying different things, but nothing worked, until finally the battery died from trying to start it so many times. So I put a set of jumper cables on it, and it started right up and ran fine for about two weeks.
Two weeks ago, it happened again. I tried the fuel cutoff again - nothing. Then I put some jumper cables on it and it started right up and it has been working great until today. It just happened again today at lunch. So tonight when I was going to go home, I found someone to give me a jump. When I went back to the truck, it started right up, without the jump. I'm so confused now.
I'm pretty sure the battery is fine. It cranks really well and it will crank for several minutes before the battery dies.
I have no idea where to even start to fix this problem, and I'm getting a bit frustrated. Thanks for your help.
The first time this happened, I kept trying different things, but nothing worked, until finally the battery died from trying to start it so many times. So I put a set of jumper cables on it, and it started right up and ran fine for about two weeks.
Two weeks ago, it happened again. I tried the fuel cutoff again - nothing. Then I put some jumper cables on it and it started right up and it has been working great until today. It just happened again today at lunch. So tonight when I was going to go home, I found someone to give me a jump. When I went back to the truck, it started right up, without the jump. I'm so confused now.
I'm pretty sure the battery is fine. It cranks really well and it will crank for several minutes before the battery dies.
I have no idea where to even start to fix this problem, and I'm getting a bit frustrated. Thanks for your help.
Last edited by Guaps; Mar 8, 2012 at 07:13 PM.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
With all that your tried, the only possible clue is the PCM is not powering up through it's relay until you add jumper starting to the system.
Use your owner's manuel to located the PCM power relay and swap it with one of the others, as a start in tracking the cause by elimination.
After that is testing for fuel pressure and spark to get some sort of lead.
The crank sensor down behind the A/C compressor could be the source of a no start with a loose or corroded connector, so pull that off and reseat it.
If it fails there is nothing for the PCM to use as as the reference so nothing will work.
Good luck.
Use your owner's manuel to located the PCM power relay and swap it with one of the others, as a start in tracking the cause by elimination.
After that is testing for fuel pressure and spark to get some sort of lead.
The crank sensor down behind the A/C compressor could be the source of a no start with a loose or corroded connector, so pull that off and reseat it.
If it fails there is nothing for the PCM to use as as the reference so nothing will work.
Good luck.
Thread Starter
|
Member
Joined: Jan 2012
Posts: 31
Likes: 0
With all that your tried, the only possible clue is the PCM is not powering up through it's relay until you add jumper starting to the system.
Use your owner's manuel to located the PCM power relay and swap it with one of the others, as a start in tracking the cause by elimination.
After that is testing for fuel pressure and spark to get some sort of lead.
The crank sensor down behind the A/C compressor could be the source of a no start with a loose or corroded connector, so pull that off and reseat it.
If it fails there is nothing for the PCM to use as as the reference so nothing will work.
Good luck.
Use your owner's manuel to located the PCM power relay and swap it with one of the others, as a start in tracking the cause by elimination.
After that is testing for fuel pressure and spark to get some sort of lead.
The crank sensor down behind the A/C compressor could be the source of a no start with a loose or corroded connector, so pull that off and reseat it.
If it fails there is nothing for the PCM to use as as the reference so nothing will work.
Good luck.
Thread Starter
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Member
Joined: Jan 2012
Posts: 31
Likes: 0
I pulled the fuse box open to check out the relays. One relay is missing, and the one that handles the PCM is a different color than all the others (yellow and all the other relays are black). Is that the same for other people? I'm wondering if the previous owner replaced that relay with something incorrect...
