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Junk Computer?? 97 f250 help!!!

Discussion in 'Ford Trucks' started by MustangFox302HO, Feb 27, 2008.

  1. MustangFox302HO

    MustangFox302HO Junior Member
    from Mass
    Messages: 26

    i have done the cap, rotor, plugs, wires, pick-up coil , coil, ignition mod. The truck acts likes its skipping, losing power on the high way back roads and even at idle. after running the diagnostic the code tells me the only thing left to replace is the computer, but my mechanic says he has never seen one go b4. other possibilities are the throttle position senor but the idle isn't bad enough or acting like its bad. the o2 senor is another possibility but i have been told the o2 on this year doesn't do enough when its working right to make bad changes in lean and richness to cause a problem like richening the motor to the point where it would cause the truck to loss power. the truck is a 97 f 250 old body style with a 5.8 gas. truck has 32,000 miles yes 32,000.
     
  2. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    I would say the throttle position sensor needs replaced. But before that, I would check all your connections vacuum and electrical. Some years the vacuum reservoir fails, It's on the right fender, a 4 inch diameter can. It is a reservoir for vacuum to run the systems. If it's rusted out let me know. I can tell you how to repair it /replace it. For way less then the $35 Ford cost.
    What does the truck do?
    Runs rough, not idle well? Stall without warning? Stall when turning? Low power when working as a plow truck?
     
    Last edited: Feb 28, 2008
  3. snowcan

    snowcan Member
    Messages: 52

    The scanner should tell you if the TPS and O2 sensors are within their respective parameters, if they are then there is no reason to replace them. You need to do a further diagnostic before you guess at replacing the computer. What codes are being launched?
     
  4. tim096

    tim096 Senior Member
    from wny
    Messages: 100

    what codes do you have? did you check the fuel filter? what is the fuel psi? did you ck the egr valve ? did you ck the cat. conv.? I to doubt its the pcm.
     
  5. Spitz

    Spitz Senior Member
    Messages: 192

    I would check the eec(electronic engine control) power relay, it should be mounted on the driver side fender under the hood. When we have strange problems we usually look at this component really closely as sometimes simply touching it will stall the truck.. I'd at least grab it, move it around and tap it against the fender to see if anythin acts up.. When we replace these we replaced the harness end and the relay which you can get at any part stores. What usually happens is the terminals get corroded (they are not sealed) and can cause problems.. This controls power to the computer and can have very odd effects on it.. I believe there is two relays right next to each other in the area im talking about, one is the eec power relay and im thinking the other is just the fuel pump relay.