2006 DT466 losing prime

[Idaho Mike]

2006 DT466 losing prime after sitting for a day or two making it a PITA to start specially when it's cold until I figured out I have to prime it every time I go start it up. Any suggestions..

 

[Mr P]

Long crank time can be loss of fuel anf/or loss of oil pressure. Do you understand the HUEI system? Got a "scanner"?

 

[Idaho Mike]

Long crank time can be loss of fuel anf/or loss of oil pressure. Do you understand the HUEI system? Got a "scanner"?

The HPOP is fine with great pressure, I think it's the primer pump, when I unscrew the handle it leaks pretty bad so it may be leaking back into the tank..

 

[Mr P]

What is the pressure commanded, what is the actual pressure, what is the duty cycle of the regulator?

 

[ewo1]

The HPOP is fine with great pressure, I think it's the primer pump, when I unscrew the handle it leaks pretty bad so it may be leaking back into the tank..

What Mr.P suggested I believe you are not viewing completely... yes it could cause this issue of long start, no start when cold.

Your HPOP could be a-ok with pressure but if the injector o-rings are leaking at the HP oil rail, you will get a long start and no start when cold.
How do I know this, I am fixing the same issue!
if your curious, starting at post 75. Got it from 15-20 seconds of cranking down to 6 seconds.

2006 DT466E Rebuild

I'm surprised you went to the stealership with how much you tell us to just do it yourselves lol. Just goes to show we all have to rely on them from time to time unfortunately when they have you over a barrel or you are stuck between a rock and a hard place. I can't even use servicemaxx right...

www.skoolie.net

But in all honesty, I have not looked at fuel pressure as my primer pump has not shown sign of either leaking or needing to be pumped before cranking. I have checked.

Your primer pump has a check ball, sometimes the get stuck/contaminated with dirt causing it to stick.
worth looking at.

Got a fuel pressure guage?

 

[Idaho Mike]

When I unscrew the pump handle fuel runs out while pumping till I screw it back in. I'm going to take it out and put in another that I have and see what happens

 

[ewo1]

When I unscrew the pump handle fuel runs out while pumping till I screw it back in. I'm going to take it out and put in another that I have and see what happens

Yup, bad primer for sure!
Don't forget to inspect the check valve too...

Figure 549 Fuel filter header assembly
1. Housing cover assembly
2. M12 port fitting (factory fill)
3. O-ring seal
4. Fuel filter element
5. O-ring seal
6. Fuel pressure regulator assembly
7. Plug or EFP sensor (optional)
8. Fuel filter housing
9. M10 Plug assembly
10. Fuel strainer
11. Bowl O-ring seal
12. Fuel bowl (with heater option)
13. Drain valve
14. Fitting assembly, 3/8 tube
15. Water drain valve assembly
16. Self tapping screw (4)
17. Cartridge check valve
18. Retainer ring
19. Primer pump assembly
20. Bolt, M8 x 20 (2)
21. Primer pump seal
22. Water In Fuel (WIF) sensor
23. Stand pipe

Source:-> EGES-265-2

 

[Idaho Mike]

Copy that, much appreciated the diagram

 

[Idaho Mike]

how do I get to #17, from the inside of the canister or the outside?

 

[ewo1]

how do I get to #17, from the inside of the canister or the outside?

unscrew the plunger, bolts #20. It is inside there.

 

[Idaho Mike]

didn't want to start yanking on stuff, dark now, have to do it in the AM. Thanks ewo1

 

[Idaho Mike]

oh, does it just pull out?

 

[ewo1]

oh, does it just pull out?

Looking at the diagram , it looks like it screws into 14, a 3/8 fitting.

 

[Idaho Mike]

I'll take a look at it tomorrow morning, I don't have the canister out, doing it all in place.

 

[ewo1]

I'll take a look at it tomorrow morning, I don't have the canister out, doing it all in place.

cool, make sure you let us know how it goes. I am taking special interest in this one as I need to see if I can get my bus to start quicker than 6 seconds.

how long do you have to crank yours before it starts?

 

[Idaho Mike]

mine cranks and fires in a few seconds when everything is working together, all it takes is one little blip and game over..
This morning it was 37 so I wanted to see how it would start cold. checked the prime which was gone so I primed it first, then purged the air out the top of the cannister but only cycled the air heater once, damn it, I should have cycled it a few times, anyway it did start after about 15 seconds, smoked like a burning tire then took off, pulsated for a while till warm then all was fine.
I plan on pulling the backflow valve tomorrow morning and look for something stuck in the seal and go from there.
I have been messing with this truck for over a year now starting in Florida. I know this motor inside and out, kinda. Learned a ton about it. I will definitely be posting my trials and errors so to help out others in narrowing down the troubleshooting..

 

[ewo1]

mine cranks and fires in a few seconds when everything is working together, all it takes is one little blip and game over..
This morning it was 37 so I wanted to see how it would start cold. checked the prime which was gone so I primed it first, then purged the air out the top of the cannister but only cycled the air heater once, damn it, I should have cycled it a few times, anyway it did start after about 15 seconds, smoked like a burning tire then took off, pulsated for a while till warm then all was fine.
I plan on pulling the backflow valve tomorrow morning and look for something stuck in the seal and go from there.
I have been messing with this truck for over a year now starting in Florida. I know this motor inside and out, kinda. Learned a ton about it. I will definitely be posting my trials and errors so to help out others in narrowing down the troubleshooting..

Funny you say Florida. My bus was a Broward county bus. That's why it has no heaters or block heater.

 

[Idaho Mike]

mine was from cali then somehow ended up in florida, now in idaho, it has no block heater, just the air box heater, I did get a hot start but might put it in my xterra if I can get this rig working the way it should..

 

[Mr P]

smoked like a burning tire then took off,

Smoke means fuel is there, just is not lighting due to insufficient heat.

 

[nikitis]

I'm no mechanic, but White/blueish smoke means oil is there as well which is why I believe EWO1 mentioned the injector rings being worn as a possibility. Dark smoke means too much fuel. My bus has had the white/blue'ish smoke happen on rare occasion but it's rare when it occurs, then seems to heal itself and never occur again for 9 months and tends to only happen when it's cold, never in the summer time. I don't know why it happens in winter, maybe the metal is contracting and allows oil through?