Engine/Transmission (1994 - 1998) Changed fuel filter...no start

[KnightR]

Although I have a 98 it has a 96 engine thus a spin on fuel filter. Did not put fuel in new filter, but primed about 100 time and fuel comning out of bottom . Suspect air in lines now. How do I bleed air out or any suggestions.

 

[EKlem]

If you have access to an air compressor, the easiest way to do it is to lightly pressurize the tank with your bleeder screw cracked. You can wrap the air hose in a towel and stick it into the tank. If you have any form of an air leak in your fuel system, it is really hard to get it to prime.

 

[Woodenhead]

Although I have a 98 it has a 96 engine thus a spin on fuel filter. Did not put fuel in new filter, but primed about 100 time and fuel comning out of bottom . Suspect air in lines now. How do I bleed air out or any suggestions.

Fuel coming out of bottom? You're not using the water drain in the bottom of the filter to bleed the air are you? If so then you won't be getting the air out of the filter. I usually just crack the filter loose, use a broom handle to pump the primer then crank it till it starts.



Even after doing return lines, injection lines, remote filter installation etc. (lotsa air in the system) this still worked for me.



Mike

 

[KnightR]

Thanks for the quick response guys but I guess the name of the games is prime prime again. I certainly will use the examples put forth for the next encounter. Again a sincere thanks.

 

[MMcCallie]

Just to clarify, the spin on fuel filter has a water separator at the bottom of it that you had to reinstall from your old filter. Should be black, hard plastic i think. It has a collar on the bottom that will slide up and down and fuel/water will drain out of it. That's not what you should be trying.

The lift pump is engine driven, mounted directly to the block, below the filter, beside the fuel pre filter/heater. It should have a black rubber boot on it that points toward the driver's side frame and fender. It will likely be very stiff to push. Can often take a couple dozen pumps to prime an empty filter.

As mentioned by EKlem, you can loosen the screw on top of the filter assembly to aid in priming the system by letting air escape past the filter so it will fill more easily. If the priming is working, you should be able to hear a very faint high pitched whistle from the top front of the fuel pump each time you depress the lift pump to let you know when fuel has gotten as far as it should. It shouldn't whine until it is primmed.

I once spent over 40 minutes priming and cranking trying to start my truck. Ran the batteries dead cranking, had to jump it just to keep cranking. Even ether wouldn't get it running. Also tried using an air compressor to pressurize the tank and fuel lines. Was thinking it wasn't going to start but it finally did.

Eventually, my truck didn't start at all after several hard starts just a couple months later. Replaced the lift pump and overflow valve and haven't had those starting problems anymore. After you've tried everything, including making sure the tank has fuel, you may want to start by replacing those two parts.

Many say these mechanical lift pumps are indestructible but i know from experience that they sometimes need to be replaced. You could also try running a fuel line directly into a can of diesel with a cheap electric fuel pump. Likely won't put out nearly as much fuel as it should but it might give you hint as to whether or not parts are failing you. You could also try filling the filter and see if that helps it start.

 

[Joe G.]

A couple of years ago I had the same problem. After a lot of struggle, I found that the fuel heater had burned up. It worked before I changed the fuel filter, but not after. It was a big puzzle until I found that it was a fuel heater problem. Just in case that is what has happened to yours, remove the fuel heater and throw it away. It's worthless anyway.

 

[wcjp]

Don't forget to crack one or two injector lines to help bleed air. After replacing the Orings in my 96' lift pump I had to use low pressure air at the gas tank with rags to help seal. I used 15psi. Another time the fuel preheater assembly was loose and the internal gasket was shot. Also, had a severely dryrot fuel preheater to lift pump soft line.