95black2615

I don't see any visible fuel leaks. It started fine just after installing the new pumps. A day later and it cranks more to get it to run than it should. Truck is a 2000 five speed 2wd.

The only symptom I see is that when I bump the starter to try to get the lift pump to run It doesn't come on like it should for the 30 seconds.......Although it did when I first installed the VP44 and the fass and I was bleeding the system.

I checked fuel pressure. It is 20 at idle and reving it up it drops to 15. Is it supposed to keep pressure in the fuel line while shut off?

I got a rebuilt pump from sheid diesel. The truck had dead pedal, which is now fixed.

chainzaw

Try tightening down the injector lines at the head. You could be getting air in the lines.

rattlerbob5.9

High lift pump pressure at start up can cause hard start/long crank time issues.

Junk Man

Sequence on my 2000 is: Key to run - Airdog kicks to 15 then returns to 0.
Key to start - engine cranks & starts immediately. Fuel pressure solid at 15# idling. Drops to 13# under load.

I too just installed a VP & experienced longer crank. I think it was a leak somewhere in the lines and I went through all of the connections. The injector lines from VP to head are under pressure and they will be wet if they leak. Use carb cleaner or something on a hot engine to clean up after bleeding to get 1st start. Make sure injector 6 isn't leaking. Remove the stock lift pump & engine lifting bracket to get there. You don't need the stock pump with FASS or ADog anyway. Removing the stock LP caused a boost leak because the gasket on the manifold the LP is mounted on was old and brittle.

Now move to where fuel the line connects to the VP. It should be clean & tight. Again, clean with carb cleaner.

Check the return line that Ts at the back of the head.

Now, under truck, check fittings pump from tank and return lines. Finally, check the connection(s) at the tank. I think most problems will be caused by the supply line or the return line forward of the fuel pump.

Tazman

I think there's something related to the LP not cycling anymore.

My last fresh VP swap had the same thing only it never cycled.

Taz

Junk Man

VP only kicks the 1st time, then will again after a few minutes. I haven't looked for reason but know that 1st key on gives me 15# on the gauge. We can surmise all day but until he actually checks fuel lines or finds something else wrong, we are urinating in the wind. Any codes? Did you clear them after the VP install?

95black2615

codes have been cleared when the pumps were installed. No codes.

The FASS pump I have bolts into the factory lift pump bracket, so the factory pump is long gone. It bolted on just above the starter.

I won't see the truck until the weekend, so I'll have to try all the suggestions then.

bigfish95971

You may check/clean/replace the crank shaft position sensor. Also, did you replace the fuel filter?

95black2615

The fuel filter was replaced when I did the pumps. There was a pile of particles at the bottom of the filter housing. I took it off and cleaned that all out

KATOOM

Just posted this on another thread and didnt feel like re-typing so I copied.

If anyone who has ever replaced their fuel pump (usually with a high volume fuel pump) and is having issues with the truck not wanting to start when the engine is at operating temperatures then this is whats happening:

The VP44 has a small internal valve called the pintle valve which moves everytime a cylinder receives fuel. It seems that when the VP is cool the pintle valve moves fine but when warm the tolerances change causing it to be more intolerant to higher fuel pressures and sticking while the engine is cranking. Ever see the Dodge sticker that says minimum 7 psi while cranking? Well it should read 7 psi "maximum" while cranking and is probably a misprint but I cant prove that. I just know its wrong and has mislead us VP guys for years. Aftermarket fuel pumps are notorious for pumping at higher fuel pressures than the OEM lift pump which is why this rarely happens to a stock truck BUT that wouldnt keep me running an OEM lift pump, subjecting the VP to terrible volume and low pressures and hot temperatures.

So to stop this from happening there are two options. One is a reflash which stops the FP from pumping while cranking or you can install a relay in the fuel pump wiring that does the same thing. I did the relay and it works perfect. If you have a FASS or Airdog or Raptor or whatever, DONT turn down the fuel pressure to help it start. Why risk the VP? Just fix the problem and keep the VP happy and cool.

If you're not sure this will fix your problem and you dont want to go through the trouble just to find out its not then do this..... When the truck is warm and wont start right away, take a second, remove the fuse to your fuel pump and then try again. If what I said is your problem, the truck will start instantly.....but just remember to put the fuse back ASAP.

Now if you have a problem starting when the engine is cold then what I said does not pertain to you and you most likely have a fuel leak and should confirm that by parking the truck over night with the front pointed downhill and see if it starts better the next day.

BigGreen

I wish I knew this much about these 24V I feel dumb just looking at it. My question is this so should I do the air dog or fass or leave the stock.

KATOOM

My answer to that involves another question. How reliable do you want your truck and what do you ask of your truck? The OEM lift pump setup is horrible and extremely none reliable. Its not a matter of if but when it will fail and take your VP44 along with it. From experience and reading these forums for years (which by the way is the best way to gain knowledge of your truck) I have found that the VP44 knowledge base has come to the point where we KNOW that anything under 10 psi of fuel is very bad for the VP, even though I'm convinced thats still way to low. Why? Because VP needs more fuel than it uses to cool it like your radiator cools your engine. With that said the VP has a overflow valve on the return line that lets fuel run back to the tank when the pressure gets over 14-16 psi. By setting your fuel pressure to a MINIMUM of 15-16 psi at WOT you're making sure that the VP is always getting more fuel than it needs and is keeping cooled (or cooler) by the fuel passing by.

If you also have any concern for whats currently going on with your engine, you need a fuel pressure gauge, pyrometer, boost, and tranny temp if you have an auto. Those gauges will help keep you out of trouble.