| Author |
 Topic  |
|
|
joeheb
Senior Member
121 Posts |
 Posted - 01/14/2013 : 11:56:55 AM
|
| DT 360 won't stay primed. About once a month we would need to prime the fuel to get it started. Now it's every other day. We've replaced primer pump and all fuel lines (not steel injector lines). I'm starting to think a check valve or the injector pump itself. Any thoughts? Bus runs fine once it's started, but if it sits for a day or two it'll need to be primed for it to start. |
|
|
eddo
Senior Member
USA
62 Posts |
Posted - 01/15/2013 : 09:58:27 AM
|
I don't have much to help, other than to say that I have 2 of these engines, and I absolutely love them. They are the most dependable things I have (7.3's, 466's, 466e's, 6.0's,)
We have (fleet wide not here,) had these trucks rub a hole in the fuel lines where they go over the frame near the tank. I have also had the fuel line fittings be loose enough to suck air, but not be lose enough to leak. Also, the replacement fuel lines (the rubber ones that connect to the pump, not the plastic ones out of the tank) do not last anywhere near as long as the originals.
None of that has caused the issue you speak of here, but it might give ya a thought or two to get you in the right direction. |
 |
|
|
Fastback
Top Member
720 Posts |
Posted - 01/15/2013 : 11:14:38 AM
|
| I assume you have replaced fuel filters and the problem persists? |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
tigger2
Advanced Member
USA
230 Posts |
Posted - 01/15/2013 : 12:08:34 PM
|
| On the side of the injection pump there is a line at the front or the rear that is bolted with a banjo bolt through a stand off fitting, that fitting is the pressure regulator and check valve the spring inside can break or the plunger can be damaged by debries. Also look at the valves under the primer pump and the nut( right next to the pump) on the lift pump assy mounted on the side of the injection pump these valves should be in one piece as should be the springs. Some of the earlier engins used a stanadyne filter(glass like a John Deere) that leak air when the spring clamp gets weak or the o rings get hard, bypass it and see if prime is held. We replaced all of ours with spin on fuel water seperators. |
|
|
|
joeheb
Senior Member
121 Posts |
Posted - 01/16/2013 : 05:29:45 AM
|
@eddo all fuel lines been replace and connections are good.
@Fastback fuel filters have been changed and still looses prime.
@tigger2 will definetly check all you mentioned.
Will keep yall posted thanks for the tips. |
|
|
|
C.HARDY
Advanced Member
236 Posts |
Posted - 01/16/2013 : 4:43:21 PM
|
| I had a 7.3L doing the same thing and mounted a seperate check valve in the fuel line before the pump. It was a inexpensive fix for a spare bus. I also had a DT360 that wouldnt start below 60 degrees.....had to replace the injector pump. |
"Hardybusman" |
|
|
|
joeheb
Senior Member
121 Posts |
Posted - 01/18/2013 : 06:38:05 AM
|
| Update: Tried replacing the fuel pressure regulator/check valve, still looses its prime. Gonna try the lift pump next. |
|
|
|
sob
Senior Member
USA
53 Posts |
Posted - 01/22/2013 : 05:31:46 AM
|
| Possibly a cracked pickup tube in the tank ? Just a thought.....Does the fuel level in the tank make any difference. |
|
|
|
joeheb
Senior Member
121 Posts |
Posted - 01/22/2013 : 06:51:07 AM
|
| Replaced lift/transfer pump, it quit loosing its prime. The bus starts like it should. Thanks for all in the input. |
|
|
| |
Topic |
|
1990 DT 360
