Fuel pressure

[Sp6saz]

Hi, folks 2006 dt466e international experiencing hard starting. My primer pump leaks about 3 tablespoons of diesel when I open it and I have a pressure reading of 50 psi with the needle shaking when running when I shut it off the pressure drops down to 0 zero within 10 seconds. If I prime with the hand primer before starting it starts right up in like 2-3 seconds but if I let it sit for a couple days and don't prime it takes 3 or more times of cranking for like 10 seconds or more and finally starts but is trying hard to catch up and actually run. Any help appreciated. I'm new to the buses or any diesel for that matter.

[ewo1]

Originally Posted by Sp6saz

Hi, folks 2006 dt466e international experiencing hard starting. My primer pump leaks about 3 tablespoons of diesel when I open it and I have a pressure reading of 50 psi with the needle shaking when running when I shut it off the pressure drops down to 0 zero within 10 seconds. If I prime with the hand primer before starting it starts right up in like 2-3 seconds but if I let it sit for a couple days and don't prime it takes 3 or more times of cranking for like 10 seconds or more and finally starts but is trying hard to catch up and actually run. Any help appreciated. I'm new to the buses or any diesel for that matter.

I had a similar problem on bus we were building. We replaced the prime pump and problem solved.
You got an air leak for sure… but where?

[Sp6saz]

Originally Posted by ewo1

I had a similar problem on bus we were building. We replaced the prime pump and problem solved.
You got an air leak for sure… but where?

Thanks for your response I appreciate it and the other stuff you posted for me earlier on about the hard starting the pages you sent were a great help and I really appreciate that. Do do you have a repair manual for these engines or what

[Booyah45828]

You did all the diagnostics you need to. The primer pump leaks fuel and needs repaired.

Everything before the actual lift pump is under vacuum. So the primer pump, filter, water separator, hose, fuel pickup. etc. are all under a vacuum and subject to air intrusion issues. If you have fuel leaking at the hand pump, you more then likely have air leaking too. What happens is that after you shut it off, the air leaks into the hand pump/system, which allows the fuel to return back to the tank. With the line full of air now, there is no fuel to the engine, and it won't start until the air is purged and the fuel system re-primes.

Hand pumps leaking on these are the #1 culprit for hard start/no start after sitting for awhile. With fuel being thicker then air, if you have a fuel leak at the hand pump, it's almost a guarantee that air is leaking into the system at that spot too, and is the cause of your problems.

[Sp6saz]

Originally Posted by Booyah45828

You did all the diagnostics you need to. The primer pump leaks fuel and needs repaired.

Everything before the actual lift pump is under vacuum. So the primer pump, filter, water separator, hose, fuel pickup. etc. are all under a vacuum and subject to air intrusion issues. If you have fuel leaking at the hand pump, you more then likely have air leaking too. What happens is that after you shut it off, the air leaks into the hand pump/system, which allows the fuel to return back to the tank. With the line full of air now, there is no fuel to the engine, and it won't start until the air is purged and the fuel system re-primes.

Hand pumps leaking on these are the #1 culprit for hard start/no start after sitting for awhile. With fuel being thicker then air, if you have a fuel leak at the hand pump, it's almost a guarantee that air is leaking into the system at that spot too, and is the cause of your problems.

Thanks, I hope your right I bought a new seal for the hand pump today hopefully that fixes it and I'll be a happy man.