86 300
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86 300
ok,on the back of the engine there seems to be electrical connections to a vacume system,the past owner unpluggeg these connections,the engine runs really rough till u speed it up ,i mean really rough,like the engine sways back and forth,wut are the connections and stuff for and wut could cause the rough idle,thx all
Tuned
Joined: Jan 2006
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I have a 1985 I6300 in a van. On the inside of the hood is a schematic of the vacuum system, fast idle & ISC (idle speed control). This system has sensors on temp, throttle opening and other items. I believe it sends this info back to the computer which changes timing amoung other things. There is also a feedback solenoid mounted on the carb. I believe this setup was Fords trainning guinne pig for their EFI system. When I bought my van the wires to this vacuum valve bank were covered with oil, which rotted the insulation on the wires. I had mutli exposed wires all jumbled together. I was lucky it did not cause a fire. Might be the same thing that happened to the PO of your truck.
Look for the schematic under the hood or ??? Good luck trying to get it back to stock. I would tell you where my wires/vacuum connected to but all the wires, computer, feedback carb are in a box wating for a slow death with .22 rounds.
Look for the schematic under the hood or ??? Good luck trying to get it back to stock. I would tell you where my wires/vacuum connected to but all the wires, computer, feedback carb are in a box wating for a slow death with .22 rounds.
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Joined: Mar 2006
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You are basicially screwed. The 86 300 is the worst setup ever made. It is a computer controlled carburetor AND ignition system. (computer controlled fuel injection = good, ordinary carb = good, computer controlled carb = bad ) It never worked right when new, good luck getting it to work when this old, and if the various hoses, etc are missing, forget about it. And a rebuilt carb is like $ 300!
I should know, I have one. (1986 F-250 with the 300) I recently bought a rebuilt carb, 1970 vintage, fully adjustable with manual choke. Plus I bought a Duraspark II distributor and module system for a 1980 vintage 300. I'll let you know how they work once I get them installed.
I should know, I have one. (1986 F-250 with the 300) I recently bought a rebuilt carb, 1970 vintage, fully adjustable with manual choke. Plus I bought a Duraspark II distributor and module system for a 1980 vintage 300. I'll let you know how they work once I get them installed.
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Joined: Jul 2004
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one of those solenoids goes to the EGR, the other two control the valves for the air pump and cat ... my truck doesnt have a cat or air pump, and i disconnected the EGR caus it didnt work right anyway, so i just unplugged the connections to the solenoids and removed them all ... i didnt like the feedback carb i had either, so i got an earlier non-feedback carter yf and put it on ... runs great ... next on my list is switching to duraspark II dist and ignition box ... this is on an 84 f150 with the 300 of course ... so id say you dont really need to worry about them unless you have to pass emmisions ... 300I6VAN85 is right about the schematic thing though, itll help if you need to hook them all back up, that and/or a manual ... just my 2 cents ...
Last edited by dvldrmmr; May 6, 2006 at 01:36 AM.
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1979, 300, 86, carburetor, computer, controlled, f150, feedback, ford, schematic, swb, troubleshooting, vacuum
