Ok, the truck in my signature. Ive had the losing prime problem since i bought the truck. It was bone stock when i bought it. It has the problem where if the nose is parked uphill, or on level ground, it loses prime and cranks for about 8-10 seconds before starting. I usually just bump the key and let the airdog run for a few seconds before i crank. The problem doesnt exist if the nose is pointed downhill. I know it's a common problem, and that there has to be an air leak in the system. Good fuel pressure, no noted fuel leaks. Since i noticed the problem i have done replaced/installed the following things fuel system related.

-Airdog lp
-injection pump including new banjo bolt
-injectors, new copper o rings
-banjo bolt on back of the head
-checked the high pressure fuel lines for leaks
-checked the connecting tubes for leaks/damage

After doing all this i figured i would have come across the problem... But it STILL does it. What else is there to check???

 

Have you checked for issues with the fuel module in the fuel tank?

Sent from my Droid2 @ 1.4ghz

 

yes the fuel module is a good place to check. we have alot of trouble with this.

 

did you replace the o-rings on the connector tubes when you had them out?

 

Didnt replace the o rings on the connector tubes but all looked ok when i had em out. What happens with the fuel module to make it leak? I guess just buying a whole new unit would be a start to check that... While im in there i could do a draw tube for the airdog 100... thats an idea... The tank may be coming out this week i guess

 

if you do a draw straw...just make sure you get that thing as close as possible to the bottom of the tank. if not you will def have the 1/4 tank issue. and may still have it after putting one in. orrrrrr you could look into putting in a sump in the bottom of your tank. hellman make a nice billet sump for that application. then you wouldnt have any issues at all getting fuel outta the tank

 

Yeah. It just confuses me why running the ad100 out of the stock draw is giving me the 1/4 tank prob... Doesn't make much sense

 

Do the Vulcan Draw Straw and you don't have to worry about 1/4 tanks issues.

Sent from my Droid2 @ 1.4ghz

 

We have had the hard start/lose prime deal happen, we started leaving our fuel caps loose so we dont pull a vacuum in the fuel tank.

I dont know if the cap or the tank itself is suppost to be vented or not but if we leave ours tight and drive aways then take the cap loose it sucks a bunch of air.

Simple solution, leave the cap loose dont pull a vacuum on the system, it never looses prime anymore and its better on the lift pump.

 

Interesting. I'll try it. If it works maybe I'll just drill a hole through the cap. Anyone else's input on ^^^ that one