Hey guys! It's been awhile anyways, I came into town back to where my 79
F-150 was from Sacramento now I'm heading to Washington from Central Oregon and I have to work out some kinks the truck has accumulated over the past 6 months. Strange how things get worse even if they the truck just sits there isn't it? Anyhow, I've been trying to figure out these problems the past couple days and i'm convinced that i need help. So, the main to problems are fuel and trans shifting. Both worked flawlessly before i parked the truck.

With the fuel, i have a Holley electric fuel pump by the fuel tank which goes to a Holley fuel pressure regulator which then pumps into a Edelbrock 1406 carb. When cruising, it runs great. But when in park or at idle, when you snap the throttle, it bogs down before it starts to rev up. I looked inside the carb and it looks like its not spraying enough fuel. Also when you're driving and you step on it, it'll rpm up bet once it reaches about 3,000 rpm, it gets choppy. Rpm's go from 3,000 to 2,600 back to 3,000 constantly until you let off the throttle. There aren't any kinks in the fuel line, no matter what i adjust the pressure regulator to, it doesn't change, same with the carb adjustment screws and the timing. I don't know if i'm missing something. Any ideas?

Now the tranny is giving me problems too. It's a c-6 behind a 400 and it was rebuilt a few years ago and has been going strong ever since. It acts like the kick down is set to full throttle all the time. It wont shift until like 3,400 rpm and will downshift if i shift it from 2 to Drive even if im driving at 1,800 rpm. I've tried adjusting the kick down but it doesn't do anything. I haven't checked the fluid levels but would that be a problem?

Any input helps! I'm trying to make a 5 hour drive on Friday and i get the feeling that i should really make sure these problems are solved so i'm not stranded half way between.

Thanks guys. You ROCK!!

 

Sounds like you have some trash/debris in the carb and the accelerator pump is probably bad as well. It could be fuel pressure as well. Fluid levels in your transmission would certain cause issues if it is low. Also check the vacuum lines on the vacuum modulator. Vacuum leaks will cause issues with both the engine and transmission.

 

This sounds like the problem my fleet truck had and it ended up being plugged exhaust. Vacuum was compromised by excessive backpressure bothered both fuel and trans shift. NOt sure what you have for exhaust but if not free flowing it maybe plugged.

 

X2 on what he said.

Did you park it real full of fuel or real low on fuel? If it was low fill, it up with gas and add a can of Sea Foam, change the fuel filter, and the accelerator pump on the carb.

Trans Ck the fluid, and any thing that might of been moused on while you were gone like vacume lines...

 

Check the vacuum modulator and the vacuum line that runs to it.
Pull the vacuum line off the modulator, see if trans fluid runs out of the modulator. If it does, the modulator is bad. If it doesn't, it still could be bad.
Check the vacuum line, see if it's disconnected or bad.

 

Awesome, thanks you guys! I'll look into it and tell you all how it goes!

 

So i did a little digging and the fuel problem ended up being a kinked fuel hose that i missed. Has great throttle response and no bogging down.

The trans on the other hand is another story. Fluid levels were solid, no noticeable open vacuum lines other than the one that comes up being the carb. Hose was cracked. I replaced that but didn't seem to be the problem. I tried re positioning the kick down but it ended up causing the throttle to stick open. It's pretty freaky when it catches you off guard going through a neighborhood. Could there be an issue with the kick down? I haven't looked into it that much. Could it move freely up top but be stuck down below? I'm just pretty lost on the thing...

 

Also could it be old dirty fluid? I just realized that I've had this trans rebuilt about 2 years ago and haven't changed the fluid once. I feel stupid thinking back on that.. If so, how would you properly do it? I heard there is a special procedure to do it since you wont get all the fluid out just by draining it?

 

Clogged filter? Drop the pan (tilt it to prevent a big mess) then change filter and put in new fluid.

Or...take it to a place that can connect to radiator/trans lines and with it running pump the old fluid out and new in, is the way to completely flush the trans and the converter.

They say you can DIY, but you better be careful to not run the new trans fluid bucket empty during the process.

Trans issue. https://www.ford-trucks.com/forums/1...l#post14696866

 

Thanks guys! You rock.