Ok So I Put In a 351W in my 86 F150 4x4 dose fine till I run her on the road I get her cruizeing in 3rd gear at about 35 or greater and the engine bucks or bogs like it has a miss in it when you mash the gas, goto a lower gear and she is fine, Also the rear 2 barrels dont appear to have any gas flowing out of them, good MPG I guess :-), but is this a problem? How to fix? Any Ideas?

Thanks
JT

 

Is it ok in the lower gears when you mash the gas? Could be a clogged fuel filter? Find out why your not getting gas through the whole carb and that will solve your problem.

-Jon

 

The fuel filter is brand new, I have no Idea if there should be fuel in the back 2 barrels, can anybody help?

 

If it is not the filter then I would guess that It is not getting enough fuel. I would tend to say it is definatley fuel related if it runs fine on half throttle. I would check the fuel pressure and then go from there!!

 

Hmmm fuel pressure? dose that imply that I have a fuel pump? I have looked and see none, the thing just sucks gas like a straw, no pump, that I know of, I know there should be one, but I have never had one, the one in the tank must be dead, should I have another?

 

Your not serious i hope.

-Jon

 

Could be the torque converter

OR

On my 93 5.8 it was crud on the INTAKE MANIFOLD side of the EGR valve
They cleaned it out and problem went away

 

Got a manual, so torque convertor is a wild shot and the fuel pressure, yep I am not kidding is that a little problem, I am getting really good MPG!

Where should the fuel pump be, in line or in the tank?

 

>Ok So I Put In a 351W in my 86 F150 4x4<

So, what did you have to begin with. If you don't have a fuel pump, it ain't gonna work unless you always go down hill. Did you have EFI? If so, you're pump is in the tank and your probably pumping at 45-50 psi and the carb only wants 4-7 psi...Your mechanical fuel pump should be on the driver's side of the engine sticking into the timing chain cover...

 

>>Ok So I Put In a 351W in my 86 F150 4x4<
>
>So, what did you have to begin with. If you don't have a
>fuel pump, it ain't gonna work unless you always go down
>hill. Did you have EFI? If so, you're pump is in the tank
>and your probably pumping at 45-50 psi and the carb only
>wants 4-7 psi...Your mechanical fuel pump should be on the
>driver's side of the engine sticking into the timing chain
>cover...

It had a 351W that the guy before had put in the vin says it should have a s6 not a v8 I have been working fine up/down hill for about 40 miles no EFI, just carbbed, I have been on a 45degree incline no prob let it sit there and fine, no gooseing the gas..... I just checked the engine, I am an idios there is a mechanical fuel pump, like you said right beside the timeing chain.

But dose this mean it is clogged or what?


Thanks To All!

 

[updated:LAST EDITED ON 02-Mar-02 AT 08:34&nbsp;PM (EST)]I believe there is a fuel filter in the frame rail under the cab and also another filter at the carb where the fuel enters...You still could have an intermittent problem with your mech fuel pump..or the carbon cannister is plugged not allowing enough gas to the carb...or you have garbage and/or water in the gas tank???

Oh, I don't think you will see fuel in the rear bbls until close to WOT.

 

DITTO!! Thro away the old pump and hose between frame and pump.
Your truck should have a #4180 holley carb w /vac secd's andoubt if you would ever see them come open while tuning. If shure their not working try a new secd diaphram For more secd tuning try a spring kit to vary time when it happens. I read where a lot of people like edelbroch but Ford has alway selected a HOLLEY. These thing can be modified to kno end. be aware that any chgs can make biiig changes in the way it runs.
caddy 53

 

Got some engine pics on my website, if you could check out, http://www.chspyder.com/exp/f150 I dont have any real things setup, carbon canister, missing, most all emmissions are gone, all I have is engine, some vacume lines, for brake booster, and spark advance (could this be on the incorrect vacume setting), and a carb, I dont, know if this one is a holly, it dosent have any of the traditional holly markings, I have another one i'll try today, also hope to check compression and the plugs/wires, fuel filters, and lines.


If anybody knows where I can get some GOOD diagrams for the engine wireing, or vacume please help! Haynes, Chiltons dont have enough stuff!


Thanks To ALL!!!