86 f-250


stegomon

15+ Year Member

V8 Engine Swap
Joined
Aug 9, 2007
Messages
2,197
Points
3,101
Age
41
City
auburn/minot maine
Vehicle Year
1987/1990
Transmission
Manual
got an 86 f-250 efi 302...no balls..no power..yada yada yada....know how to fix it.....swap in a 4bbl!!!!good bye efi...haha...any who...i dont know what the tranny is....i think it is the aod...if so....can i make that tranny work with a carb set up?
 
No balls because it needs a 460. It won't make more power by adding a 4bbl. Look down the throat of a 4bbl. You have 4 little 1" venturis in there, with booster venturis and other assorted junk in the way, then a 90* turn at the bottom and runners going everywhichway. So 4 1" venturi's is 506mm^2 and one 60mm TB is 2,800mm^2 in area. It would take a really big carb to flow with an EFI--and that large of a carb wouldn't have enough airspeed through the venturis to pull the fuel out of the bowls at low speeds. And the EFI has no 90* bend for the air to slam into. The carb needs disturbances (like venturis which choke the airflow to make the air speed up for the pressure drop to pull the fuel up through the jets) built into the system to keep the fuel particles from seperating out. The EFI flows more air, period. Why do you want to choke your engine? That's not very much engine for an F250. Like I said, the real answer is get a 460. Even a 5.8 is kind of weak in an F250.

And the computer is probably doing the 3-4 shift and the converter clutch lock-up.
 
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What kind of EFI is it? If it is throttlebody then there are probably better ways to get the fuel to the engine.

I doubt a 1986 has a computer controling much of the transmission.

Also remember that this thing is 22 years old, how good of shape is the engine in? A 3/4 ton is a lot of truck for a healthy 302 anyway...
 
An 86 would be multiport I believe. In any case, not TBI. Should look similar to this:
86 f-250


I'd second the 460. The 302 in my F150 feels like it has a ton of power, but no torque. Pulling trailers and stuff just kills it.
 

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