Blowing fuses and not running! - Chevrolet Forum - Chevy Enthusiasts Forums

Blowing fuses and not running!


  Reply  
  #1  
Old  June 5th, 2010, 5:12 PM
  • CF Beginner
    Join Date: Mar 2010
    Posts: 11
    Shreveport, LA
Blowing fuses and not running!

Hi Guys,

I have a ploblem with my 2002 Z71. It's got a 5.3 L engine and an extended cab. I was idling at a gas station and it died. It would turn over fine, but wouldn't start. I noticed that the gas gauge showed empty and I knew the tank was nearly full. I started checking fuses and found one blown in the fuse box under the hood. I replaced it and the gas gauge showed full again, but the truck still wouldn't start. After trying it a few times, the same fuse blew again and the gas gauge showed empty again. I'm pretty sure I have a short somewhere and I'll have to trace it down, but I'm hoping somebody here may have seen this happen before and can give me a place to start. Thanks for any help,

David

  #2  
Old  June 5th, 2010, 6:12 PM
  • Super Moderator
    Professional Mechanic
    Join Date: Nov 2008
    Posts: 2,955
    Bowie, MD
You need to see what you are lacking, fuel or spark then go from there. I would suspect fuel. What is the fuse labeled?

  #3  
Old  June 6th, 2010, 10:22 AM
  • CF Beginner
    Join Date: Mar 2010
    Posts: 11
    Shreveport, LA
Hi MDTAHOE,

Thanks for the reply. I put a fuel pressure gauge on the fuel rail and got no pressure at all while cranking the starter. I replaced the fuse and still got no pressure. The fuse that's blowing is labeled ECM B. Is it my fuel pump, or is it the computer?
Thanks for your help,
David

  #4  
Old  June 6th, 2010, 11:25 AM
  • CF Beginner
    Join Date: Mar 2010
    Posts: 11
    Shreveport, LA
update

I went and bought an Actron OBD II reader. With the blowing fuse replaced, it says 0 codes and with the fuse removed, it says NO LINK. I'm at a loss and feeling pretty frustrated.

David

  #5  
Old  June 6th, 2010, 12:32 PM
  • Super Moderator
    Professional Mechanic
    Join Date: Nov 2008
    Posts: 2,955
    Bowie, MD
Unplug the fuel pump connector and see if the fuse blows. I highly suspect a blow up pump.

  #6  
Old  June 6th, 2010, 1:13 PM
  • CF Beginner
    Join Date: Mar 2010
    Posts: 11
    Shreveport, LA
I'm not sure where to unplug the pump. Will I have to drop the fuel tank to get to the plug? The fuse doesn't blow now, so will unplugging it now tell me anything? I can't hear the fuel pump running when the key is turned on or during cranking. I even used a stethoscope and couldn't hear anything. I have a Haynes manual that shows how to remove the fuel tank. Once again, thanks for your help.
David

  #7  
Old  June 6th, 2010, 2:21 PM
  • Super Moderator
    Professional Mechanic
    Join Date: Nov 2008
    Posts: 2,955
    Bowie, MD
ECM B does have the fuel pump on it.

  #8  
Old  June 6th, 2010, 7:15 PM
  • CF Beginner
    Join Date: Mar 2010
    Posts: 11
    Shreveport, LA
Well, I syphoned out all the gas I could get out of it this afternoon and I guess I'll drag out the transmission jack and try to drop the fuel tank tomorrow afternoon. Maybe once I get the tank dropped, I'll find some short or broken wire I can fix and not have to buy a new fuel pump. Those things are expensive! I appreciate the help. Wish me luck.

  #9  
Old  June 7th, 2010, 5:25 PM
  • CF Beginner
    Join Date: Mar 2010
    Posts: 11
    Shreveport, LA
re-update

I dropped the tank and pulled the fuel pump. I couldn't find anything obviously wrong and I didn't know what the resistance should be on the pump motor leads. It read 0.7 ohms - not open windings and not a dead short, so it really didn't tell me anything. I decided to go ahead and buy a new fuel pump anyway and I'm glad I did. I put it in and remounted the tank, which was not as tough a job as I was afraid it was going to be. The truck is running great now. in fact it was idling a little rough before, so maybe the pump had been going out for a while. Thinking back, it did die at a red light about a month ago and wouldn't start for a minute or two. Do these fuel pumps quit intermitantly when they're on the way out? Thanks to MDTAHOE for the useful info,
David

  #10  
Old  June 7th, 2010, 5:44 PM
  • CF Active Member
    Join Date: Apr 2010
    Posts: 294
    Michigan
what was the millage on it when the pump went out?


  Reply
Tags
Search this Thread
Sponsors