MISS/ROUGH IDLE???

[93f250idi]

Went out today an drove the truck around got home went out about 2 hours later drove it to my neighbors as soon as i stopped at his house it started missing / rough idle so i let it run for a second an it cleared up. shut it off talked a few got back in started it up an it died as soon as it started. cranked on it a second got it started drove back home done the smae thing when i put it in nuetral. has a brand new fuel filter an no water is coming out of the seperator when i open it? it will do it everytime i drive for a second then let it idle. any ideas what it could be??? thanks!!!!! sorry i dont have a video camera to show exactly what it does

 

[suv7734]

How much fuel is in the tank?

 

[smolkin]

How much fuel is in the tank?

This. It sounds like it's sucking air from somewhere. Have you checked the schrader valve at the filter head for air?

 

[93f250idi]

How much fuel is in the tank?

right in between 1/4 an 1/2 tank but ive ran it way below a 1/4?? an whats a schrader valve?

 

[smolkin]

right in between 1/4 an 1/2 tank but ive ran it way below a 1/4?? an whats a schrader valve?

A common problem with these trucks is the bottom part of the fuel pickup in the tanks breaking off. This usually causes them to suck air at 1/4 or below. The schrader is the tire-stem-valve-looking thing on the side of the fuel filter head.To see if you're sucking air, get a small PLASTIC (metal might accidently hit the alternator pos+ wire) basin and crank up the engine. Place the basin under the schrader and push in the pin in the middle with a small screwdriver or something. If you're getting air in the fuel, it will hiss and sputter out a fuel/air mix. If you get a good steady strong stream of just fuel, it may be something else that's causing your issues. Chances are it's air from what you described.

If it is, now the fun part! Fill up your tanks, and if it still runs rough even after evacuating the air from the schrader (always do that WITH the engine running or it will draw air IN) you have a leak somewhere else, and you get to hunt it down! Some people replace the return line from injector-->filter head with a clear hose to help...that way you can see bubbles easier. There are common problem spots that leak often, like at the tank selector valve, or at the "olive" fittings on the injectors and pump. It has taken me months to find some of the leaks I've had.

 

[93f250idi]

A common problem with these trucks is the bottom part of the fuel pickup in the tanks breaking off. This usually causes them to suck air at 1/4 or below. The schrader is the tire-stem-valve-looking thing on the side of the fuel filter head.To see if you're sucking air, get a small PLASTIC (metal might accidently hit the alternator pos+ wire) basin and crank up the engine. Place the basin under the schrader and push in the pin in the middle with a small screwdriver or something. If you're getting air in the fuel, it will hiss and sputter out a fuel/air mix. If you get a good steady strong stream of just fuel, it may be something else that's causing your issues. Chances are it's air from what you described.

If it is, now the fun part! Fill up your tanks, and if it still runs rough even after evacuating the air from the schrader (always do that WITH the engine running or it will draw air IN) you have a leak somewhere else, and you get to hunt it down! Some people replace the return line from injector-->filter head with a clear hose to help...that way you can see bubbles easier. There are common problem spots that leak often, like at the tank selector valve, or at the "olive" fittings on the injectors and pump. It has taken me months to find some of the leaks I've had.

thanks ill check all that out tommarow! ive been looking at all the injector return lines to make sure no leaks there and so far none but i will check again