84 2.8 rough idle and hesitation.

[Evilbronco]

So i pulled the truck out of storage. It was durasparked before the winter. Got a motorcraft 2150 installed and swapped in #43 jets. Plugged all vacuum lines including the one on the choke and the back of the spacer. Timing set 10 degrees bdc. Egr blocked. Still running a cat with glass pack. Replaced the fuel filter a few days ago. I put in a new coil from a 78 mustang to match the rest of the ignition but it ran better with the tfi coil so i switched it back.

Ok now the problem. It starts great and runs normal for a split second than idles rough. After it warms for a few there is extreme hesitation at about 1/4 throttle. It pretty much about dies then recovers. Once it gets going it seems to go away in the higher rpms. Mostly noticable between shifting and taking off. Ive checked all that i can think of. Havent done a compression test yet. Anyone have any insight?

 

[kimcrwbr1]

Try adjusting the idle air needles for the highest possible idle rpms?

 

[martin]

You say you plugged ALL vacuum hoses. You need vacuum to the choke pull off and also to the power valve.

 

[Evilbronco]

I have the needles about 1 3/4 turns out. Might have play with them more. Would that effect the hesitation?


The power valve doesnt have port on the 2150 like the 2150a does. I have the pull off connected. Everything else is plugged

 

[wildbill23c]

The initial adjustment for the mixture screws is 3-1/2 turns out, that could probably be your problem.

 

[Andy D]

I wouldn't do anything until I had run a fresh tank of gas through the carb. Also, how long did you run on the re-worked ignition? Long enough to work out any bugs? It took me a while, but after a few fiascoes, I learned to check where I last worked, before I start trying to fix what just broke

 

[Evilbronco]

Ok idle is fixed cause apparently im a knucklehead and i was thinking tighten the idle mixture to lean it out.

I messed with the arm on the power valve and got alittle less bucking and bogging. Ill do.some.more fiddling after work.

I have ran a couple tanjk of gas threw it since i put the carb on.. Before i changed jets it was getting wonderful 10 miles to the gallon. Just changing the jets before the bucking and hesitation started i git about 18 mpg. I didnt check the timing after i put the tfi coil back in so ill check that too.

Thanks all for the replies.

 

[Evilbronco]

Still hesitating when i first press the throttle.

So I checked timing and moved the power valve arm to the leanest and richest positions. Rotor and cap looked fine. Rechecked for vacuum leaks. Checked wiring.

Going to run a a compression test tomorrow.

Coil possibly? Running out of ideas. It will sometimes have nothing when the pedal pressed.