Ford Truck Enthusiasts,

Two weeks ago my son drove my 74' F-100 360 v8 about thirty miles away. While driving he had a lot of issues when driving in city traffic no acceleration, loss of power... chuging and jerking... rough idling. Now this seems to be happening all the time when driving locally. If I get the truck onto highway it seems to drive ok but local streets it run terrible.

Some mentioned that is was possibly an issue with a vapor lock.. Does anyone have any insight?


craigibc

 

Assuming you've checked the fuel pump for leakage at the weep hole, I'd spend the 20 minutes to pull the fuel pump off of the engine and check the INSIDE of the fuel pump for a leak.

If you find one, CHANGE YOUR OIL and buy yourself a fuel pump. Mine had a similiar issue until the day it just died. As it was leaking fuel internally instead of externally, I couldn't find the problem until the pump just quit.

Good luck!

 

I don't think its vaporlock. I've always understood that vaporlock makes it die. The hot gas turns to a vapor in the line and plugs the fuel line until it cools. So the engine doesn't run for quite some time.

Might want to look over the rubber fuel lines for cracks. Should be one at engine, one along frame near front of bed and one at tank. If hoses have cracks, the pump will suck air and you won't get enough fuel.

Also check the accelerator pump spray. With engine off, look down carb and move throttle. You should see two streams of fuel spraying into carb as throttle is moved. If the streams are not steady with throttle movement, the carb needs work.

Marty

 

Or check the gas cap & see if the vent is working properly

Are your fuel filters clean ?

Possibly there is a hole in the fuel tank pick up tube inside the tank


Just a few idea's ...

 

Check for a blown power valve and bad ignition.

 

Check the Lottery Numbers


Welcome to the site

IMO, you have a few delivery problem and it may run deep.

The guys have already covered the basics.

I can only add:

How old is the fuel ?

Do you buy your fuel from a BUSY gas bar to make sure you get fresh gasoline ?

Has the fuel filter been changed ?

Have the carb mixture screws been adjusted to spec ?

Has the carb acclerator rod been properly indexed ?

Has the truck been sitting for a long while before being used ?

 

You guys have given a lot of great suggestions which I will take one at a time and work through. Once I do I will post the results and get additional feedback.

I was considering buying a new Edelbrock or Holley carb but I wanted to make sure that was the main issue.

Thanks,

Craigibc