Hard to get my 79 f100 to take off.

[ARhodes1974]

I have a 79 f100 and its hard to get it to take off. I changed the fluid and strainer in it today. I have to rev the motor up high and it eases off slowly. Once it gets going it drives pretty good all the gears are changung out good and stuff.

[colnago]

Just a stab,but my 352 has very low vacuum. If it's cold out, it has real problems shifting. Do you have a vacuum gauge? If you don't, you should! Anyway, hook it up and see how much vacuum you're pulling.

Joseph

[ARhodes1974]

Thanks colnago i dont have one but im going to invest in one asap. Im thinking it might be the modulator but im definitely going to pursue getting a vacum gauge.

[jzjames]

Standard transmission?
Is the motor tuned up and running on all cylinders? Could it be your clutch?

[ARhodes1974]

It is an automatic and i just changed the plug wires distributor cap and rotor button on it the motor is running strong i was told it could be the stall in it. It has a small cam in it.

[ARhodes1974]

Thank you guys for all of your help it was the modulator valv . I replaced it and it drives like a champ now.

[Ranchero50]

makes sense.

Bump the timing to 15` initial ad it'll run better too. Stock is too retarded.