Engine miss My 86 ford truck with a 460, manual trans, 4bbl loses power at a specific rpm. Idles fine, runs good at lower rpm, but when you try to accelerate, it will rev to a certain rpm then begins to miss, sputter and backfire. This problem surfaced all of a sudden. I have tuned it up, changed all filters, but can't shake the problem. Any ideas?

Use code reader to check fault codes

Get a manual for a 86 ford econoline from an auto parts store.

Replace the catalytic converter, it is clogging up. You can just remove it, but I didn't tell you that. it's an 89.

It sounds like you might have a clogged catalatic converter on the exhaust system.

you should use the sending unit that is for the VEHICLE and the tach hooks to the negative side of the coil.
hope this helps

try replacing the throttle position sensor

Hello. katienjoe. the fuel line from the filter to the fuel rail has a restrictor in the line its at the fitting at the rail. the opening messures 3/16 of a inch. so loaded it doesn't pull above 50 mph. you can change the line I did on mine the hot rod shops can supply what you need.

either fuel filter or fuel pump...replace filter since its cheaper. 6-12 dollars at autozone

Try rebuilding your Carburator ,sounds to me your uncle is right the diaphram under the carburator,known as the power valve will cause your engine to lack power and surge as though it's looking for a idling point,and it will cause flooding, Cheaper to buy a complete rebuilders kit from an auto parts store than it is to buy knew one ! or even have it done. last time I rebuilt my ford carb I paid about $18.00 dollars for the Master rebuilder kit ! also you will need a tach and dwell meter to adjust the carb.Good Luck.

Do you have a Vac leak? easy way to find is to let run and open hood.. buy a can of starting fluid.. sprey around the Vac hoses and when the engine RPM picks up you have found your Vac leak.. hope it helps