Fuel pump stops working

tdark

Hero Member
Joined
Nov 14, 2006
Messages
316
Likes
5
Points
18
#1
Make
Chevrolet
Model
K1500 4X4
Year
1999
Miles
158,000
Engine
5.7
Hope someone might add to this problem I am having with a friend of mines truck. He calls me last Sunday and said his truck would not start. He was 20 miles way back in the woods at his cabin. I went with him Monday to check the truck out.

The fuel pump would not run. He had installed a pump 18 months ago ( Delphi complete assembly )

I swapped the relay from AC and still not start.

I also had bumped the tank with a rubber mallet thinking I might make this pump start working but that trick did not work

I then got it pulled to my shop.

We removed the bed to get the pump easy. I had him try it with bed removed and still not fuel pump running.

I then removed the wire connection that powers the fuel pump and put it back on and low and behold it started fine.

I checked fuel pressure and it had 58 psi but decided to just have him get a new pump being it had a lifetime warranty on the one he installed 18 months ago. I was thinking maybe it was defective.

I got new pump installed but in the back of my mind I just knew it was probably not going to fix it and I was right.
last night he calls me and said it was a few miles from his house. He turned it off and all was good. Two hours later he tried to start it and nothing.

I went to where the truck was this AM . I removed the gas cap and had him try it. No fuel pump working. Again I swapped the relays knowing it was not going to do any good and still nothing.

He was calling a tow truck and I decided one more time to get it to start. I turned the key on and off several times and all of sudden it started. I have no clue if what I did made any difference but it is running again.

He drove it to the shop . I lifted the bed up enough to get the wire connector off. I discovered that he had spliced the fuel pump connection with butt connectors 18 months ago when he installed the pump.

I removed those and put the wiring harness that was supplied in the pump we put on Monday. I didn't even know one came with it as he did most of the work. He said he thought it was ok.

Now did those butt connectors get loose and cause this problem? I don't have a clue but now they are soldered with a new wiring connector on it.
I cannot believe that the new pump might be bad but I assume that is possible ?

I told him to just drive it and lets see what happens. I hate when these type problems come up. How can I make it stop now that it is running fine. I tried pulling on wires that runs in this circuit and it will not stop running. :( I will wait for the phone call :)

Anyone run into anything like this on this old chevy ?

I also checked real good on the place where pump relay goes in and all looks great. Relay fits nice and tight.

I wish it had not started this morning but it did . I saved him $100 for the tow fee anyway. Cannot fix something that is running now but like I mentioned it may be back. Sorry for the long post but wanted to explain what all I have done to try and get this thing going. Tom
 

jd

Hero Member
Joined
Jan 14, 2007
Messages
521
Likes
23
Points
18
#2
Butt connection to the electric steps on our RV failed after 15 years...
 

Boomer

Hero Member
Joined
Mar 14, 2007
Messages
278
Likes
0
Points
16
#3
If it's anything like my S10, there is a test terminal in the fuse box right next to the fuel pump relay. If you have it not running again, I'd put 12 V to that terminal while listening for the pump to run. If it runs, you know your wiring from their back and the pump itself are ok. If not, make sure you have a good ground.
 
Joined
Aug 28, 2007
Messages
4,698
Likes
18
Points
38
#4
Ha, ever since OBD I came out, started paying for Towing insurance, depends on over a million super little tiny transistors to fire an injector. But at least they used PROM's for code, was permanently burned into the chip, never had problems with these.

Even worse in 1996 with OBD II storing code in a super tiny transistor with an extremely tiny electrical charge that can leak off, lose just one bit of a byte, microcontroller sees that, does not recognize the code and will crash. Marketing pushed this, with the internet, cheaper to let a dealer reflash the memory or for even updating than mailing out a new PROM that never went bad in the first place.

Latest shock was installing the fuel pump in the tank, why? Can make it cheap and rather than depend on copper and steel for proper cooling, used the fuel instead, and external fuel pump would be far superior, and in the long run, far more inexpensive to replace since most of these require you to drop the tank first, now, dey all do dis.

Ha, use to be pretty good getting a stalled vehicle running on the road, but now dead meat.

Also was working with small aircraft, had preventative maintenance, after so many hours, had to replace the brushes in an alternator as only small requirement. Never heard about preventative maintenance in automotive, just drive them until you are stalled in some God forsaken place. Even had to walk several miles to learn if somebody had a land line, least we have cell phones now.

Ha, back then could push start any vehicle, even an AT when the pump was on the driveshaft. One tiny electrical resistance in your starter circuit, dead meat, even made worse with anti-thief that was far more effective the rightful owner starting his own vehicle.

Ha, over the years, sure invented a host of new problems that were never problems before., call this progress. Now I am asking, what happened to towing hooks? On this new stuff, can't even tie down a kayak, only cheap breakable plastic up front.
 

tdark

Hero Member
Joined
Nov 14, 2006
Messages
316
Likes
5
Points
18
#5
When the truck was not running yesterday I did jump the fuel relay terminal after I swapped the AC relay to fuel pump relay. I had a pressure gauge connected to test valve and still no pump running. Picture I attached shows where I put the jump wire.

I think that would tell me it was a wiring problem from the terminal back to pump. I had power on B1 before I used the jump wire.

Again I am not sure by me turning the ignition on and off would have made it start but it did and I was able to get it off the side of the road.

I will wait and see what happens. I am thinking that when I soldered the wires that were supplied with new pump and removing those butt connectors he had installed 18 months ago might have did the trick.
Updates later. Tom
 

Attachments

Joined
Mar 1, 2002
Messages
3,409
Likes
44
Points
48
Location
Kentucky
#6
Your solder repair probably fixed the problem. But if the problem re-occurs, you will wish you had also soldered on a red wire (to power circuit) and a black wire (for ground circuit), and ran those wires to an easy access point under the fender to test/power up the fuel pump without removing the bed again.
 

tdark

Hero Member
Joined
Nov 14, 2006
Messages
316
Likes
5
Points
18
#7
Thanks Mobile Dan, I actually suggested that to him but he didn't want to so we will see. There is really no other way to tell if by chance this truck does do this again .
I do feel the solder got it resolved. I will keep you updated . Hope I don't see it again. Tom