loss of power and hesitation when accelerating

[sandmanf250]

check for carbon tracking on the cap checkthat the wires are good and not cross firing and last check the firingorder

[QC]

The plate in the dist. that the points mount on wears out. It rotates on plastic bushings when the vacuum adv. pulls it to advance the timing. When it gets loose the vacuum advance pulls the points out of adjustment, causing the stumble.
Disconnect the vacuum advance, plug the hose and drive the truck. If its better the breaker plate is probably worn out. They are available for about $10. It was the first thing I replaced when I got my truck. I got one at NAPA

[coop]

The plate in the dist. that the points mount on wears out. It rotates on plastic bushings when the vacuum adv. pulls it to advance the timing. When it gets loose the vacuum advance pulls the points out of adjustment, causing the stumble.
Disconnect the vacuum advance, plug the hose and drive the truck. If its better the breaker plate is probably worn out. They are available for about $10. It was the first thing I replaced when I got my truck. I got one at NAPA

First off Happy New Year!

Well things are definatntly off to a good start. I just got my motor cycle running again after a year all it needed was fresh gas

Then I decided I must be on a roll so I revisited the truck. I disconnected the vac advance and took it out for a spin the truck didn't have the hesitation and it ran a little better. Just for the heck of it I tested the vac advance diaphragm and lo and behold the darn thing isn't holding a vacuum the diaphragm is ruptured. I would bet that, that is the problem I am also going to check the points plate while I am in there. Off to NAPA I will let you know how it turns out.

Thanks

[coop]

I replaced the vacuum diaphragm the points base plate was fine it has a bronze bushing in it. I went all the way into the distributor and checked the weights. What I found was one of the springs look like a stock one it is a rust color and looks ok the other spring looks newer it is silver looking and courser, beefier. The bigger spring was a little loose around the stud. Shouldn't the springs be the same?

Well I put the whole thing back together and fired it up the vacuum was low around 10 and the timing was around 0 I adjusted the timing to 10 BTDC and the engine sounds a lot better the vacuum bumped up to around 17. The vacuum wasn't steady it had a little vibration to it.

I took the truck out for a spin and it was night and day the hesitation was gone and it was more responsive. But the trans isn't shifting right when I got on it, it did the same thing again it wouldn't go faster than 40 if I got off it and back on it then it shifted.

I did a post on the drive train forum about the modulator valve possibly being bad and got some input from Dragon about how to check it and some suggestions.

I guess what concerns me is that I had to move the distributor to adjust the timing from the painted mark on the distributor the truck ran fine before on the mark could that be the springs?

And the trans isn't shifting right I plan on checking the modulator valve this week.

Any ideas?

[BobbyFord]

Make sure the vacuum line is hooked up both at the manifold and at the mod valve. Pull the line off of the vac mod and see if there is any trans fluid coming out of the modulator. Put a vacuum pump on the mod valve and see if it holds vacuum(or if you don't have one you can just use a clean piece of vac hose and suck on it). Timing chains wear, points wear, both can affect timing. The springs are not your problem.

[coop]

Make sure the vacuum line is hooked up both at the manifold and at the mod valve. Pull the line off of the vac mod and see if there is any trans fluid coming out of the modulator. Put a vacuum pump on the mod valve and see if it holds vacuum(or if you don't have one you can just use a clean piece of vac hose and suck on it). Timing chains wear, points wear, both can affect timing. The springs are not your problem.

Right on, thanks for your input hopefully I will get a chance this week to check the modulator, I will let you know what I find. Thanks again for the carb info I went ahead and took it apart to check it out, everything was clean I blew out the passages like you recommended.

[Helge71]

Just a thought, as i had the same shift behaviour on my 65 Pontiac after a carb change:

Is the transmission connected to the correct vacuum source? After my carb change i had to learn that the new carb had a ported vacuum connection where the old one had manifold vacuum. The transmission shifted very strangely, more or less like you described... After changing the trans. vacuum connection to a manifold vacuum source everything was fine again and shifting was as it has been before.

Helge

[qmcdugan]

Not sayin'that this is it, but worth a thought

http://www.fordification.com/forum/view ... =3&t=46466

Long story short, I replaced the fuel hose that ran between the tank line and the steel line to the fuel pump. She now runs great. Interior cracks in the hose permitted the fuel to soak into hose and cause swelling to the point of developing a serious restriction. Additionally I think some of the debris from the hose breaking down fowled up the pump as well. Replacing the pump helped a lot but didn't address the problem completely, that's when I decided to replacee the hose.

Good luck