I have a truck with an auxillary fuel tank and Fass pump and the stock tank and a recently added Air dog pump, but the problem existed before I added the pump...I have a fuel pressure gauge installed so I know that I am getting fuel ~16 psi...at all times, but if I clutch and brake the engine hard it dies and I loose power steering until I turn it over and it fires right back up? Any suggestions? it works the same on either tank/pump so I do not think it is the pump. It also occasionally dies after clutching it after having it revved up/load on the engine, but mostly just after a hard braking? Ideas?

 

Sounds like a problem with where the fuel pickup is located.

 

Yah, how much fuel in the tank when it stalls?

 

I don't think its an issue inside the tank because I put a new fuel pump including a 1/2" pickup line in the tank and filled the tank half full. I put on an airdog pump which is supposed to remove the air, but the problem is the same as before the pump was installed. It seems like the truck has good power, but every time you step on it, it hestates just enough to make the truck lurch forward as it takes off again, and then it also stalls when I break hard. I was thinking this might be an injector issue but the truck fires right off, sounds normal and no smoke. It does seem like there is an issue with it getting fuel. Thanks for the input guys...I'm really not thinking its the intake as I have installed a new one, but i will try to check the flow...just because there is pressure doesn't mean there is enough flow....

 

An AirDog (or Fass) can remove a certain percentage of air, but neither can create fuel when none exists. Perhaps you're putting too much emphasis on the "removing air" claim.

Just a thought.
garrett

 

Are there any other factors common to it dying?

Is tank full, empty?
Hot, cold?
etc. . . .

 

Is truck automatic or stick shift? If stick do you step on clutch? If auto is it staying in lockup? try putting in neutral and stepping on brake.

 

The truck is manual and the problem has gotten gradually worse over the past couple weeks. At first it was only dying when I clutched it at higher speeds and braked it hard. Now every time I start it after letting it sit for just a couple mins, it starts right up just fine and then dies after like 2-3 secs. If I rev it a bit it stays running then after it has been running for like 20 to 30 sec it idles fine.

Stepping on the brake while in neutral does nothing...or at low speeds...only when braking from high speeds or sometimes just clutching it at high speeds. And as far as the pump goes...you are right there shouldn't be that much air to remove. I will recheck the connections.

Any discontinuous fuel flow seems to stall it. An even footfeet keeps it running, stomping on it or reving it clutching it and braking it kills it. If I don't clutch it, but just brake it hard...it doesn't die, but as soon as I clutch it, it dies. Does anyone have ideas on where i would look for a blockage in the fuel line? Or do you think air is getting in somewhere?

 

Hate to even suggest it...but you might check the volume of return fuel coming off your injectors....if a return check vavle in the injector sticks, it will dump fuel back to the tank too fast and cause the truck to die, or have hard starts. Just a though.

ALSO...what is your fuel pressure doing when all this happens?