302 problems/ bogging down

[Lane101]

I have a 78 ford f100 with a 302, i just replaced the carb, fuel pump, fuel filters, and cleaned the tank, But i still have a bogging down problem. It idles fine revs fine just runs amazing.. (in park) as soon as i put it in drive and take off it starts to bog around 10mph but if i patt through it for a sec it straightens out and runs fine. any suggestions or advice i could really use it. thanks

 

[Fellro]

Sounds like it could possibly be a stuck/nonfunctioning vacuum advance. Also need to be certain the accelerator pump is doing as it should.

 

[Lane101]

Thanks man i will look into that tomorrow, is there anyway to check and see if the vacuum advance is stuck or not working?

 

[LEB Ben]

In addition to what Roger said, I'd also take a look at the float levels.

 

[Mil1ion]

You can borrow a vacuum pump at autozone

If the vacuum advance lever doesn't actuate witrh that or doesn't hold vacuum then the Diahragm is either seized or torn.

 

[Fellro]

It seems to be an off idle issue, so not sure the floats are the issue, but it is possible. Thing to keep in mind is that the carb is not tuned to your motor, you still have to dial it in.

Oh the vac advance, it is a little harder on Fords when the linkage is not exposed, but a vacuum pump is one way, you draw a vacuum and see how the timing changes. Check to be sure you have vacuum applied to the distributor as well, just take the hose off and see if it has any when you rev it. You need to check the ignition timing with the hose off and plugged. You can check with a timing light to see if the advance is working by having it unhooked, note where the timing is, then hook up to a full time vacuum source or use a vacuum pump to watch the timing to see if it moves.

 

[5.0Flareside]

It seems to be an off idle issue, so not sure the floats are the issue, but it is possible. Thing to keep in mind is that the carb is not tuned to your motor, you still have to dial it in.

Oh the vac advance, it is a little harder on Fords when the linkage is not exposed, but a vacuum pump is one way, you draw a vacuum and see how the timing changes. Check to be sure you have vacuum applied to the distributor as well, just take the hose off and see if it has any when you rev it. You need to check the ignition timing with the hose off and plugged. You can check with a timing light to see if the advance is working by having it unhooked, note where the timing is, then hook up to a full time vacuum source or use a vacuum pump to watch the timing to see if it moves.

thats the way i've always seen it done to find out if the vacuum is right..

 

[Lane101]

thanks everbody for the advice im bout to leave now to start working on it. I will keep yall posted on the status of my truck.

 

[Lane101]

I figured it out, it was my vacuum advance, so i ordered a new one thanks for the help though