VP or something else??

[JAG1]

What, you think he has a vacuum because of the fuel cap? If so, I dunno if that would really make a difference. My AD165 can suck the fuel tank in like its a paper bag!

i read about so many bad tank vent stories that I added my own reliable tank vent.

 

Hex, that's why you're an 'infidel' .... bad tank vent problems.......... spoken from a true truck psycologist.

Edited January 7, 2014 by JAG1

[mopartechnician]

I had a 01 last week that wouldnt vent left cap loose and never had a hard start. My 02 did the same exact thing

[mopartechnician]

Ok I was doing some thinking while on a road trip. The return system is free flowing, correct? There is nothing preventing fuel from going back into the tank like a check ball or anything. So how could a bad banjo gasket on the back of the head cause hard starts? Wouldnt the pressure side be bleeding back? I guess i would have to try it to see if my theory was right. Just trying to think out loud.

Edited January 7, 2014 by mopartechnician

[Ilikeoldfords]

Ok I was doing some thinking while on a road trip. The return system is free flowing, correct? There is nothing preventing fuel from going back into the tank like a check ball or anything. So how could a bad banjo gasket on the back of the head cause hard starts? Wouldnt the pressure side be bleeding back? I guess i would have to try it to see if my theory was right. Just trying to think out loud.

I have always wondered about this theory too. Why would a return line leaking have any effect on the pressure side of the fuel system? The only thing you would be out is the fuel lost in the leak but thats it. I dont buy it honestly.

[dripley]

The leak will allow air back into the system which will allow fuel to drain back thru the overflow of the VP. At least that is my understanding. Fixing the tee and the sealing washers in the tee stopped a hard start issue I had a while back. 

[TFaoro]

I just put a new locking cap on at Christmas, and I sucked on the end of it... It vents very well. I will start checking return lines to find where air is entering the system. After about 30min of sitting it starts hard. I have started it around 4-5 times today running errands and every one has been a hard start.

[Ilikeoldfords]

Well I learn something new everyday I suppose. Not quite sure I understand the concept but I am sure anything is possible.

[mopartechnician]

Your return stops at the injectors, correct? If it didn't, wouldn't it always bleed back everything to the tank?

 

TFaoro- try running without the cap, the cap actually isn't the vent, there is a vent ontop of the fuel module. It sounds stupid but I have seen it happen.

[TFaoro]

Your return stops at the injectors, correct? If it didn't, wouldn't it always bleed back everything to the tank?

 

TFaoro- try running without the cap, the cap actually isn't the vent, there is a vent ontop of the fuel module. It sounds stupid but I have seen it happen.

Just cracked the cap and started it... Fired right up with barely any cranking!   Now.. If the vent on the top of the tank is clogged, how do I clean it so that it will work properly? I don't want to run the truck without a cap because we have tons of dust during the summer and lots of snow during the winter. My new VP won't like dirt and water 

[mopartechnician]

Drop the tank, or I think some people have cut the small vent line next to the filler line and added a vent cap from a boat. Hopefully somebody will chime in.

[TFaoro]

I am a little confused though, because the new cap does allow air to enter.   I can suck on the end of it and air does flow. It acts like it has a one way "valve" in it though because I can't blow through it??

[JAG1]

 About my tank vent....... mine is mounted under fuel fill door to the front of the fuel cap. If you look inside you'll see the room there for a vent. Fuel door will help keep most dirt out.

 

When you do this there is a risk of fuel leaking in a roll over accident. That is why the factory fuel tank vent has what is called an 'anti rollover valve' with a check ball  or flapper. The problem is they stick shut sometimes. So you should install a diesel approved inline check ball going up to the new boat vent.

 

It is a lot easier to go get a vented cap. They have their own diaphram for anti -roll over. Make sure they allow enough air to flow thru.

Edited January 9, 2014 by JAG1

[TFaoro]

Well both Vulcan Performance and Diesel Auto Power sell pumps with NEW electronics for much less the Blue Chip.

That is a major reason I chose to go with the Industrial Injection pump. The guy I ordered it through told me that last year he sold 70 of those pumps and didn't have a single warranty claim!

[wldbil95]

I have the same starting issues. Seems to happen when truck sits for a day or two. Like it,s bleed off line pressure. someone was talking about a return line check valve ?

[dripley]

The fuel system does not hold any pressure. When you turn the engine off all pressure is lost. If you have an air leak somewhere it will allow the fuel to drain back to the tank. That is most likely your issue. If you can park the truck with the nose down and see if the problem persists. Also the next time you have the hard start, just let your fuel pump cycle instead of staying on the starter. Try that once or twice and see if it helps. Both are sure signs of air getting into the fuel system.

[TFaoro]

I have the same starting issues. Seems to happen when truck sits for a day or two. Like it,s bleed off line pressure. someone was talking about a return line check valve ?

Have you tried leaving the fuel tank cap loose to see if there is a vacuum inside the tank?