1990 Ford F-150 Fuel pumps run continously

Tiny
BANDIT40
  • MEMBER
  • 1990 FORD F-150
  • V8
  • 2WD
  • AUTOMATIC
  • 317,500 MILES
I am stumped! When I turn the ign. on the fuel pump will continiously run. It should run for about 2 seconds which it does when the light resets. It does'nt matter which tank. I have a CK Eng light on and will not let me read codes until the fuel pressures up which is intermittently at best. The fuel pressure is 40 and the fuel filter is clean. I did get to get codes at a couple of times which were 85 EONR (c) and 65 EOR. These are flash codes as I don't have a code reader.The fuel is running so rich you can almost see the gas guage go down. I replaced the FP relay and the FP regulator. I also have OD not working and feels like I'm pulling a mountain when taking off. I have the EO4D.
At times when the CK ENJ. lite goes off, everything goes back to normal except for burning very rich.
The inerta switch is good.
In order for it to start quickly, I have primed the throttle body and it starts right off.
When the accellerator is depressed, It will backfire and miss, pop and sputter!! I have added a 52cm Throttle body just after pic.
Any help will be GREATLY APPRECIATED!!!!!!!!


http://www.2carpros.com/forum/automotive_pictures/178223_MVC886F_2.jpg

Do you
have the same problem?
Yes
No
Sunday, April 13th, 2008 AT 1:11 PM

4 Replies

Tiny
JACK42
  • MEMBER
You need to get a scan tool on it to pull the codes, the light could be the trans problem that you describe as well as the rich mixture. Migh tbe th eMAP sensor thinking th etruck is being accelerated so it is running the engine rich
Was this
answer
helpful?
Yes
No
Monday, April 14th, 2008 AT 10:15 AM
Tiny
BANDIT40
  • MEMBER
Your reply didn't even address the main issue!
MAP is good.
I tried using a scanner.
I can't run codes with pumps running continouisly.
Pleaes re-read the whole problem and evaluate. THANKS, Jim
Was this
answer
helpful?
Yes
No
Monday, April 14th, 2008 AT 11:12 PM
Tiny
JACK42
  • MEMBER
This could very well be an ECM problem. It controls the fuel pump via the ignition switch. Have you tried a noid light on the suspect cylinders to see what they are doing? The fuel pump relay has a power that is tied into the same power feed as the injectors. There is a tan/lt green wire at the test connector, use a test light to see what it is doing, that is the trigger for the fuel pump from the ECM
Was this
answer
helpful?
Yes
No
Wednesday, April 16th, 2008 AT 9:03 AM
Tiny
WILL12463
  • MEMBER
Very old posting but a problem that has an unusual solution given all the funky duel tank, pressure regulator, fuel pump issues.

First thing, the pumps run when they are not suppose to. That is a control issue, pumps are controled by the PCU. Change the PCU.
Was this
answer
helpful?
Yes
No
Sunday, September 19th, 2010 AT 12:07 AM

Please login or register to post a reply.

Sponsored links