1986 F-150 driveability problem
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From: Pa
1986 F-150 driveability problem
Someone please help !!!!!
I have a '86 F-150 4X4 w/5.0 EFI, AOD, and I am baffled with this problem: while driving, it acts as if it either runs out of gas or even like the key just got turned off, then just as quik as it stopped...it starts to go again. But during the time when it (seems to) stall out, i can put it in neutral & it runs fine, but as soon as i put it back in gear & my foot on the gas, it starts all overagain. I have done a fuel press. check.......about 38 lbs. at idle, I've replaced plugs, wires, cap, rotor, module, pick-up in the dist. & even the coil as I had a problem with the green wire on the coil causing drivability problems a couple weeks ago. But now I'm not sure what to try next, any help would be greatly appreciated.
I have a '86 F-150 4X4 w/5.0 EFI, AOD, and I am baffled with this problem: while driving, it acts as if it either runs out of gas or even like the key just got turned off, then just as quik as it stopped...it starts to go again. But during the time when it (seems to) stall out, i can put it in neutral & it runs fine, but as soon as i put it back in gear & my foot on the gas, it starts all overagain. I have done a fuel press. check.......about 38 lbs. at idle, I've replaced plugs, wires, cap, rotor, module, pick-up in the dist. & even the coil as I had a problem with the green wire on the coil causing drivability problems a couple weeks ago. But now I'm not sure what to try next, any help would be greatly appreciated.
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From: Right Next to U
Does it do it while idleing?Let it idle for about 30 min to see what the engine does....sounds to me like it could be the fuel relay or the fuel regulaor...if its the fuel regular, check it by while the engine is running, disconnect the vaccum line thats on top of the fuel regulator to see if any fuel comes out, if it does...its bad, to check the fuel relay near the battery....inside the fender well, use a tester for checking the voltage, the haynes manual gives it, but I don't have it with me right now...its in the shop. but if you don't have one, I'll go an get it or someone here can let him know....
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From: ann arbor mi
i had this prob with my 460 a while back and ha to replace the igniton box on the lefthand side inner fender..... it would cut out after a while or even crazier would fire with the key just being in the run position.. not in start.. crazy.. there were many rpobs in this area...
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From: Pa
checked the regulator.....seems fine,,,,,the relay for some reson is on the firewall in the top left corner just under the hood hing, this also seems to be working. I checked the TPS according to the haynes manual......I think it's ok too. It will idle fine all day, it's only when I'm driving that it will cut out, as soon as it comes off idle while moving, but slip it into neutral & it will rev up or even stay at higher RPM's, but put it back into gear & it starts all over again. Just getting ready to put a match to it.
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From: Right Next to U
Have you check ALL the vaccum hoses? Inline fuel filter (Cost around $6.00)When it cuts out ...is it hard to restart?IHAd you checked the EGR? Is the Throttle body dirty? What condition (color) are the spark plugs? Have you pulled any codes?If so what were they?
Fleet Mechanic
Joined: Aug 2002
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From: Swansea SC
check the ignition module
It could be the igntion module shorting out and when cold again making contact .I had this happen on my 1985 4.9 -driving down the road shut off then few minuets start again 5 miles same over and over man did i replace a whole bunch of stuff GOOD luck TR PS (FORD HAD A RECALL ON THESE )
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From: Clinton
Please help
Black Ford XLT If you read the orig. post he said he replaced the module and the distributor internals as well as tuned up the truck
however you may have a point because on my 86 5.0 the ground to the module was intermittantly open causing symptoms similar to the ones descibed in the post..Might be worth while exploring
however you may have a point because on my 86 5.0 the ground to the module was intermittantly open causing symptoms similar to the ones descibed in the post..Might be worth while exploring
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From: Hallettsville, Texas
Could also be from a loose wire in one of your connectors going to your coil or distributor. Do you have a busted motor mount that could be causing the engine to torque up once it is under load possibly pulling on some of the wire connectors. Could also be a loose ground from your battery to your engine loosing contact when the engine torques up under load. Sounds electrical to me with a possibility of a busted motor mount. Good luck.
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From: Pa
GOOD NEWS.......Ithink. After checking out all replies, I put in a new throttle position sensor(even though according to the Haynes manual it tested fine), now it runs fine. Now another problem developed, it seems the torque-converter isn't lockin up. It goes into O.D. fine, but no lock-up, any ideas???
Many, many thanks !!!!!!!
Many, many thanks !!!!!!!
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