Problems with my '78 Ford F-150

Discussion in 'Shop Talk' started by tbishop, Dec 30, 2004.

  1. tbishop

    tbishop Well-Known Member

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    I bought a f-150 with 77,000 actual miles on it. The body looks like most in Minnesota. It had a 302 in it.

    When I drive it, it seems to run fine for about 8 miles or 10 minutes. Then it starts losing power and mis-firing. It keeps getting worse the longer I drive it. Eventually it continues to stall.

    There are two possibilities to the problem from what I can see. First- the guy who had it before me had someone that worked on the distributor. I wonder if he put it in wrong. When I tried to time it, I put it to 8 degrees before tdc. It ran worse.

    The other thing I've found wrong with it is that the water pump is leaking. only when it warms up, but it does leak. I wonder if when it starts to leak it could affect something.

    Anyway, if anyone has any ideas, I'd appreciate it.Thanks!!

    Tim
     
  2. LisaT

    LisaT Well-Known Member

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    I may be way off here but, would be worth checking the catalytic converter. Friend had a 78 LTD that would run about 10 min then miss and stall. Would have to sit about 45 minutes or so then could start it up and go again. Happened to accidentaly looked under the car and saw the cat glowing. Pulled the cat off and all was well. Like I said I may be way off here, but would not rule it out.

    Theront
     

  3. tbishop

    tbishop Well-Known Member

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    Now see- I was thinking about the exhaust because it seemed to happen more after it got hot. Like something was being restricted. 78 was the first year they put them on there if I remember correctly.

    Tim
     
  4. DrippingSprings

    DrippingSprings In Remembrance

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    Also Fords are notorious for the ignition coil to ground from one wire to the other or from wire to the sides fo the coil or anything metal. It will then get hot and then it will quit til the coil cools sufficiently then it will crank right up again and repeat all over again. Where the two small wires and the main wire going to the distrib connect cover with good electrical tape and see if it helps. If so go down and buy the plastic cover for the wires that prevent just such grounding.
     
  5. DrippingSprings

    DrippingSprings In Remembrance

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    as soon as it stops running feel the sides of the coil if it seems overly hot there is your prob
     
  6. fordy

    fordy Well-Known Member

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    .............The water pump has a Weep hole on the botton side of the housing directly under the impeller shaft . When the seal wears out coolant will start leaking out of this hole and you know it's time for a new pump . You will have to remove the fan assembly which is bolted to the fan pulley with those 4 bolts . Once the fan is out of the way you may beable to remove the water pump housing without removing the Radiator . Regardless , you'll still have to Drain the radiator to change the pump and you might as well replace the Thermostat while you have everything apart . One other thought .....Since you're going to go to all this trouble , you would be very Smart ....to take the old radiator...OUT...and take it to a radiator shop , and have Them , ROD it out . They will physically push a small metal rod thru each of those vertical cooling vanes and force any accumulated blockage out of the vanes . Sometimes they cannot be unclogged and must be pinched off and soldered Shut so they won't leak . The last time I had this done it was about 65 bucks or so . fordy.. :)
     
  7. agmantoo

    agmantoo agmantoo Supporter

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    Replace the water pump and install a new coil :) Drive it a 100,000 more and then change the timing gear and chain.
     
  8. Keri

    Keri Well-Known Member

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    Hi tbishop, been a member here for along time but never posted.(love this board) Just stumbled across your post. My husband had the same problem your having on his old ford pick up. ('78 f250 4x4) Turned out to be the shear <sp> pin at the bottom of the distributor that holds the drive gear on the distributor. Pull the distributor out & see if thats what happened to your truck. Your timing will keep changing too. Cost under $1.00 to fix. Hope this helps. :)
     
  9. agmantoo

    agmantoo agmantoo Supporter

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    Keri, once the pin shears the vehicle will not run ok until it is replaced. The original post stated it runs fine for a few minutes then the problem arises. :)
     
  10. Keri

    Keri Well-Known Member

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    Yup,..thats because the gear is slipping on the shaft. Thats exactly what was happening to our truck. Ours sheared right off yet it looked like it was still in there. The truck would run for a little bit then sputter & mis fire, then die. Our pin was in two pieces & looked like it was still in the shaft yet we were still able to run for a few miles before it acted up. Plus the timing kept changing. Just trying to give him another option. (easy to check too) :)
     
  11. paden

    paden Well-Known Member

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    If you stop driving and let it idle after the hiccups, does it seem to idle fine? Inadequate fuel flow will usually idle fine and drive down the road fine for a few minutes till the bowl is empty, then chug, cough and sputter.

    If it is truly a miss I would check electrical...plugs, wires, coil etc. as mentioned.

    If it isn't a miss but is running out of gas in the bowl, replace fuel filters, it may be that the carburetor is unable to keep up with the demand for fuel. If the outer carb filter is plugged, there is a screen under the float needle seat that may be plugged and the bowl may be full of gook. If this is the case make sure to put a good inline filter before the filter at the carb. The filter at the carb is not a positive filter, if it plugs up the fuel will bypass it and clog the screen inside. If your tank is dirty you will be removing the carb top weekly to clean the float screen without a good aftermarket filter. Easier to replace an inline filter periodically than clean the carb.
     
  12. insanity

    insanity Well-Known Member

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    That would also be my guess! A plugged vent on the gas top might do it to.
    As for checking for a seared pin on the distributor just pull the cap and try turning the rotary button by hand if the pin is sheared you can turn it.(no need to lift the hole thing out).If you do pull the distributor make sure you do it on level ground.Other wise lining up the oil pump shaft can be real fun.Made that mistake once,it will send you in to several cursing fits guaranteed. :D
    I also seem to remember hearing of a coil acting just like that.
     
  13. tbishop

    tbishop Well-Known Member

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    This is all great stuff!! I have changed the fuel filter. It ran better than originally. But still had the longterm problem. When it started "chugging' (sorry I don't know how else to describe it), I would put it in nuetral and then it'd let me hit the pedal without stalling. I will get my father-in-law to look at it with me.
    I need to change out that water pump. I like the idea of getting the radiator worked on at the same time.
    I really appreciate all the advice. I should have asked on here months ago. It's a good old truck. I think the fact that it sat for four years makes me think the filters are plugged. Anyway, thanks for all the advice.

    Tim
     
  14. paden

    paden Well-Known Member

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    It sure sounds like the float needle screen may be plugged. It is a fairly simple operation to remove the carb top, remove the float and unscrew the float needle seat to find the screen.
     
  15. qwerty

    qwerty Well-Known Member

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    i have done mechanics for 16 years and sounds like part of it is timing chain/i also owned the same year for with a similar problem that after 2 weeks of goin through everything ended up being rust in the fuel tank
     
  16. herefordman

    herefordman Well-Known Member

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    If it sat for four years you can guarantee the gas turned to mush, your probably going to have to clean out the whole fuel system and replace fuel filters several times before it goes away for good.
     
  17. raymilosh

    raymilosh Well-Known Member

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    one way i use to determine if it is a problem with the sparking system or not is to hook up a timing light to the coil wire and fish the wires to the timing light inside the cab of the truck through the window then go for a drive. When the truck starts misfiring, fire the timing light at the dashboard and see if the flickering light falters along with the truck. If so, then the problem is in the ignition system....i'd suspect an overheated coil as the other folks have mentioned. if not, i'd suspect that the engine is "running out of gas" due to restricted flow somewhere, low fuel pressure or "vapor-lock."
     
  18. unioncreek

    unioncreek Well-Known Member Supporter

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    I'd say that it is fuel related, probably a plugged inlet in the tank. The F150's didn't have a catalytic converter in 77, so they probably didn't in 78.

    Bob