Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

Fuel Pump Problems

 
  #1  
Old 11-23-2009, 03:02 PM
Hendrixx's Avatar
Hendrixx
Hendrixx is offline
Freshman User
Thread Starter
Join Date: Sep 2009
Location: Barrie Ontario
Posts: 43
Hendrixx is starting off with a positive reputation.
Fuel Pump Problems

my 86 f150 with a 90 5.0 motor in it will not run. i did a swap and changed the 86 harness onto the 90 motor. the wire for power to the fuel pump was cut, so when i put it back together, the pump pumps, and i can seperate the wires, get in the truck, and itll start and run till the gas is gone, but when i hold the wires together the pump does not shut off when it builds pressure like it should. what could be the problem? i also dont have a belt on the front of the truck yet, still finishing her.. but it runs, but it only runs if the fuel pump is constantly running. PLEASE HELP!
 
  #2  
Old 11-23-2009, 03:39 PM
subford's Avatar
subford
subford is offline
Post Fiend
Join Date: Aug 2005
Location: Easton,Ks
Posts: 21,969
subford has much to be proud ofsubford has much to be proud ofsubford has much to be proud ofsubford has much to be proud ofsubford has much to be proud ofsubford has much to be proud ofsubford has much to be proud ofsubford has much to be proud ofsubford has much to be proud ofsubford has much to be proud of
The pumps do not shut off with the engine cranking or running.
The fuel pressure has nothing to do with the pumps running or not running.
 
  #3  
Old 11-24-2009, 09:12 AM
Hendrixx's Avatar
Hendrixx
Hendrixx is offline
Freshman User
Thread Starter
Join Date: Sep 2009
Location: Barrie Ontario
Posts: 43
Hendrixx is starting off with a positive reputation.
i thought that when you turn the key on you hear the pump pumping fuel, then itll stop, then you start the truck and it pumps again or runs off some gravity feed **** or something. So is it okay if i just connected those wires? it would mean that the pump always pumps when the key is on and running too..
 
  #4  
Old 11-24-2009, 11:59 AM
fishforlife2007's Avatar
fishforlife2007
fishforlife2007 is offline
Elder User
Join Date: Feb 2009
Location: louisville, ky
Posts: 704
fishforlife2007 is starting off with a positive reputation.
Originally Posted by Hendrixx View Post
i thought that when you turn the key on you hear the pump pumping fuel, then itll stop, then you start the truck and it pumps again or runs off some gravity feed **** or something. So is it okay if i just connected those wires? it would mean that the pump always pumps when the key is on and running too..
without the pump doing what it is supposed to do (pump), then how do you expect the truck to run? that initial noise you hear is the pump coming on and ensuring that there is fuel pressure, and it continues to run after that. if you dont beleive me when its running disconnect the fuel pump harness and see how long it runs. not too long....
 
  #5  
Old 11-24-2009, 12:06 PM
Blue Rebel's Avatar
Blue Rebel
Blue Rebel is offline
Posting Guru
Join Date: Jul 2004
Location: Cottage Grove, WI
Posts: 2,242
Blue Rebel has a good reputation on FTE.Blue Rebel has a good reputation on FTE.
that initial noise you hear is the pump coming on and ensuring that there is fuel pressure, and it continues to run after that.
No... it does not. The pump primes for 2-3 seconds when the key is turned to "Run", but then shuts off until after the key is turned back to "run" from the "start" position. If the engine fires up, the pump will then continue to run, but if it does not, you will hear another prime, and it will again shut off.

As far as your problem, sounds like something in the prime circuit isnt hooked up proplerly. Ford changed alot when they went to the 87-91 body styles when it comes to wiring, your gonna need to get the correct schematics and trace some things out.
 
  #6  
Old 11-24-2009, 02:11 PM
Hendrixx's Avatar
Hendrixx
Hendrixx is offline
Freshman User
Thread Starter
Join Date: Sep 2009
Location: Barrie Ontario
Posts: 43
Hendrixx is starting off with a positive reputation.
alright thanks man, you were more help than the two guys sounding like smartasses. i know the pump has to pump, but it DOES shut off when it builds pressure, and i know it runs after the truck starts... but as i was saying if i put power to the pump it doesnt shut off after a few seconds like it should.
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Meanmike86
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
2
05-10-2013 09:24 AM
deltajuke
1987 - 1996 F150 & Larger F-Series Trucks
6
02-20-2013 08:57 AM
Broncboy86
1966 - 1977 Early Broncos
5
01-15-2008 01:14 PM
MikeFlorida
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
7
02-21-2007 09:27 AM
EvilAerostar
Aerostar
9
11-28-2001 02:44 AM


Thread Tools
Search this Thread
Quick Reply: Fuel Pump Problems


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.