typical 86 issues
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typical 86 issues
I have a 86 FI with part throttle issues, it will miss and start bucking. This is what I have done: new TPS, MAP sensor, IAC valve and sensor, distrubutor, moudule, air temp sensor, knock sensor. Before changing the knock sensor I just unplug it, truck ran great just had to use 93 octane. That just lasted for a little while and it started it again put the new knock sensor in with no change. The truck idles fine sparkplug look good. What else could it be. thanks in advance
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Originally Posted by daboot
I have a 86 FI with part throttle issues, it will miss and start bucking. This is what I have done: new TPS, MAP sensor, IAC valve and sensor, distrubutor, moudule, air temp sensor, knock sensor. Before changing the knock sensor I just unplug it, truck ran great just had to use 93 octane. That just lasted for a little while and it started it again put the new knock sensor in with no change. The truck idles fine sparkplug look good. What else could it be. thanks in advance
Have you gotten the codes read? That will be alot better than throwing money at it. My freinds truck did that and his fix was new spark plug wires and fuel injector cleaner.
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You might want to check your wiring in the cab & engine bay, you might have a short. For all you know, you've got a few wires that are rubbed raw. I had that with a courier I had years ago. Took me forever to figure that out.
Edwin
Edwin
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Originally Posted by scottddove
this is a obvious thing but what about both of the fuel filters did you change them.
If was a wiring problem woundn't have issues at all rpm ranges, it idles fine and wide open it runs fine.
Last edited by daboot; Oct 6, 2007 at 12:47 AM.
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From: sunny fla sometimes windy
2 bottles of heet and 2 bottles of iso heet on whatever is in the tank 3/4, 1/2, 1/4 dump it in run it until almost empty, refill with fresh gas 87octane and 2 more bottles of iso heet. I bet the truck will free rev in neutral like an animal but run like crap with a load right? That is a symptom of water in the fuel, water has a high surface tension so it is partially blocking the small openings in the system it will let some fuel through but not enough for all conditions!! Also at night get a spray bottle and fill with water spray your plug wires from dist to plugs, start truck turn off all lights, look for sparks jumping between plug wires, to metal on the motor, and to low voltage wires If you see any you need to reroute the wires or cover them with split loom. You are losing
spark energy if you have alot of errant sparks.
spark energy if you have alot of errant sparks.
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i have the same problem on my 86 ford f150 and i have replaced everything on it that Daboot has replaced, except for the knock sensor. I have pulled the codes on it and it says during (koer) that their is a problem with the thermactor system- Code 44 and the knocksensor is not getting signal- Code 25 Where do i go from here?
thanks for any responses
thanks for any responses
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From: sunny fla sometimes windy
Put a multimeter set to milivolts on the knock sensor and tap next to it with a punch and a hammer it should generate a few volts with every tap. If not the wires are very tiny inside there and could be corroded or broke!! Check all the vac lines too
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Sorry for the delayed response. Dont know what I have done sense my last respone but the truck but it is running fine know. I drove it 100 miles with no hiccups. I dont think it was water in fuel I have the same problem since March. I will say I unplug the egr sensor the truck did bog. thanks for all the responses
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From: sunny fla sometimes windy
My friend chased a problem for months throwing sensors at it, checking wires, running fuel injector cleaner by the truck load. Finally he listened to me and did the gas line dryer it was like a new truck!! Water has high surface tension it can sit in small orfices
not letting fuel through or letting just a little bit through.
not letting fuel through or letting just a little bit through.