Ok, we took all the hoses, etc off of the 360 in my BIL's 71 f100 today, painted the engine and painted the bay. Hooked everything back up, and it fires, and runs, but misfires occassionally. (At least I assume it is, it's a slight popping coming from the exhaust intermittently. i checked everything, seems to be alright, and hooked up as it should, we didn't change anything, and suddenly it's misfiring.

We took it for a 2 minute drive, and it acted like it didn't want to shift to 2nd or 3rd, (in fact, I don't think it did at all)

What are you first recommendations I should check. What things are the most likely, in what order? Thanks, fellas.

 

A buddy of mine had the shifting problem when he painted his engine in his vette. It was some vacuum hose that came from the tranny into the carb. Any thing like that on the truck?

 

I think I know the exact sort of occasional miss you are talking about because my 289 in the Stang does the same thing.

I haven't worried about it because I hope to be building a new engine soon, but I did ask my engine guy about it just because I was curious more than anything else and he suggested it was probably the ignition coil. Haven't tested the theory myself because if I hope to build an engine soon I figured why spend the time / money on the one that I have.

Might try giving the motor a good tune up with new distributor cap, coil, wires, plugs, etc. if you haven't already done so.

 

302 of my friend has occasional popping as well that I can't get sorted.
It's on driver side bank only (he has no crossover, it's only in left exhhaust pipe)
i thought it's crossfiring between cylinders 7-8, but I seperated those two cables as far as I could. no joy
that shifting problem is probably a vacuum hose missing from manifold to the can on the gearbox (whatever it's called). if it's missing it would cause to have no kickdown anymore.

 

I'm seconding that. Gotta be a missing, disconnected, or broken vacuum hose for the transmission kickdown. If the tranny isn't being supplied with vacuum, it thinks you're at full throttle and won't want to upshift. Meanwhile, the vacuum leak is causing a lean misfire.

 

Thats what I suspected too. As soon as I get changed here, I'm going to go check everything. Thanks for the 2nd opinions guys. Just didn't wanna waste my time on things it might not be.

 

Two cracks in one of the vacuum hoses. Thanks for all the help, fellas.