Ford F-150

Tiny
TGF150
  • MEMBER
  • 1985 FORD F-150
  • 6 CYL
  • 2WD
  • MANUAL
  • 130,000 MILES
I have a 85 f-150 with 4.9 inline six. My problem is it has no power and acts like it's running out of fuel. I have replaced everything I can think of. Fuel pump, rebuilt carb, complete ign. Sytem, complete charging system. Also replace cat and had exhaust checked. Replaced all vac lines. Also replace map sensor, temp sensor, and throtle posistion senors. I am still have the same problem. The c02 sensor and the egr have been replaced also. Need someone who know 80's fords to give me new ideas.
Friday, February 25th, 2011 AT 9:21 PM

7 Replies

Tiny
CARADIODOC
  • MECHANIC
  • 34,358 POSTS
Collapsing pickup screen inside the fuel tank.
Was this
answer
helpful?
Yes
No
-1
Saturday, February 26th, 2011 AT 2:53 AM
Tiny
TGF150
  • MEMBER
  • 4 POSTS
Thanks for the tip. That was something I was think about to check next but forgot about. I will check the screen. Ran into that problem on another car long time back, thanks.
Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 8:17 AM
Tiny
TGF150
  • MEMBER
  • 4 POSTS
Just a quick thought, I was thinking it may be the computer gone bad. I have been told in the past that they can go into a run mode. Where it will run, but with no advance in timing. It does not have vaccume advance, it is done by the computer. Not sure how to test.
Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 8:34 AM
Tiny
CARADIODOC
  • MECHANIC
  • 34,358 POSTS
If you mean "base timing" mode that lets you set the distributor before the computer takes over, I can only share what Chrysler did around the same time. Unplugging the two-wire coolant temperature sensor would kill all timing advance from the computer.
Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 9:57 AM
Tiny
TGF150
  • MEMBER
  • 4 POSTS
There is a procedure to check base timing. I have done that when I replace the complete ignition system. Timing is on, my question is, I was told long time back the the car in the 80's era had a fail safe mode. If the computer went bad, it would lock itself in a run mode, no advance, no retard. As I understand it, it was to get you home or to the dealer. If this is true, how do you check the computer to see if it is working properly. It does control timing, fuel mixer, and vaccume related sensors. Don't want to buy a new one to find out that's not problem. I still need to check fuel tank as you suggested. Thanks again.
Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 6:34 PM
Tiny
CARADIODOC
  • MECHANIC
  • 34,358 POSTS
If you check with a timing light, you should see it advance when you increase engine speed.
Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 6:54 PM
Tiny
CARADIODOC
  • MECHANIC
  • 34,358 POSTS
Forgot to mention, if you remove the inlet tube from the fuel pump you can give it a shot from a compressed air nozzle to possibly blow the pickup screen off. (Loosen the fuel cap). If you have a sintered metal type of fuel filter that screws into the carburetor, add an older Chrysler filter inline to catch the debris the in-tank screen is supposed to catch. That filter will last the life of the vehicle.
Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 7:00 PM

Please login or register to post a reply.

Related Catalytic Converter Replace/Remove Content

Catalytic Converter Replacement
GUIDE
Catalytic Converter Replacement
The catalytic converter is a critical component of your vehicle's exhaust system, responsible for reducing harmful emissions by converting toxic gases into less harmful...
VIEW MORE