i just bought a 85 ford f150, 4.9 carb engine 4 speed tranny, 89,000 miles on the truck ... when i first got it, it was not running, alot of wires had been messed with so i had to wire a push button ignition, after that i drove it, and it felt like it had no power and it would stall out on hills so i adjusted the distributor and got power then replaced the fuel pump and it ran great for 10 mins then the clutch blew... so i changed the clutch and ran perfect for a week... changed the oil drove it around than all of the sudden it stalled it will idle but when i try to go in first gear it feels like its about to die and after about 3 trys trying to catch it in first the 4th time it caught it had no power at and moved like a snail ... so i parked the car where i broke down and the next day came to get it and i fired it up and bearly made it up the hill before it stalled again,the next day i fired it up and it ran perfect again no stalling ton of power so idk... could it be somthing with the timing or do you guys think somthing else is wrong i mean it shifts beautifully and the engine purrs so i dont thinks its the tranny or engine but idk ... maybe new plugs and wires and distriubutor ... any help is appreciated
I believe that your truck originally came with the infamous feedback carburetor. It is somewhat hard to follow from your description but it appears as if the feedback system has been "tampered" with. The best course to take is to search the forum using the keyword "feedback carburetor" or similar and read all you can so you can better diagnose the issue (or issues). Perhaps you could post some underhood shots and likely one of the experience guys/gals will chime in. You may be dealing with a combination of issues (not uncommon with a 25 Y.O. vehicle with an unknown history).
Just remember; the search function is your best friend on the site.
at this point, your best bet is to swap out all the feedback mess for a traditional carb, unless you absolutely need to be stock for an emissions inspection. this has been written up many times, so i won't waste our time giving the basics again, unless you need help with something