FUEL PROBLEMS AND A 50 CAL. SHELL

craneman · **Posted:** Fri Dec 10, 2010 10:18 am

I would like some ideas. i have had the air in fuel problem for about 6 months now. here is what i have done to fix it.
cat fuel filter mod. no help
raycor complete fuel filter head, filter and heater, no help
kennedy fuel pump at the tank, no help
im thinking of 10 rounds of 50cal shells at 30 yards and then burn it.
i fell so let down after last weekend spent under the truck installing the fuel pump. after i was done she started like a champ. but on monday morning went out to go to work and just like days of old she started ran 10 seconds and then died. had to pump the primmer on the raycor and she started. so tuesday i removed and redoped all of my connections thinking i had missed something but that was not the answer. i love the diesel but hate the diesel all in the same breath. im sure the neighbors think im nuts, screaming and cussing at 6am everyday, at a truck that will not start. any ideas????????????????? :( :( :(

onthehunt · **Posted:** Fri Dec 10, 2010 10:40 am

Is the original fuel head still on? I would check the lines going back to the tank. Sounds like you have an air leak. I thought the lift pump would overcome any leaks? Any codes?
I've had many .50 cal days with mine. It is a love/hate thing.

craneman · **Posted:** Fri Dec 10, 2010 11:16 am

thanks for the response, i feel the pain. it dose not have the origional head. complete replacement with the raycor set up. the lines are rubber but only for about 10" then it all goes metal. unless the factory connection is leaking between the two there is no other spot for a leak that i have not double checked. im totally baffled.

reka12 · **Posted:** Fri Dec 10, 2010 11:37 am

Obvious first...Is the lift pump working? I am assuming it is not in the tank. Disconnect inlet side line at filter, turn key to on and check. You may want to use a jar and see if air is coming through (sort of like bleeding brakes). If air is coming through, check fittings at tank. If no fuel, check pump.

Sorry for the problems. Sounds like a pita.

onthehunt · **Posted:** Fri Dec 10, 2010 11:40 am

I would check it for codes. The Cat fuel filter mod has taken out injection pumps before. You can also use a sight glass installed inline to check for air in the lines.

craneman · **Posted:** Fri Dec 10, 2010 11:45 am

if i didnt have an injecton pump in working order i dont think the thing would even start. it runs fine after you blead the air. i thought the fuel pump eliminated the air probem but i guess i was wrong. after you start and run it it seems fine for the next few starts. its only when it sits for an extended time, ie overnight. i know im getting air from somewhere but the where is the million dollar quest.

warp2diesel · **Posted:** Fri Dec 10, 2010 11:47 am

The snap connectors on the fuel line out of the tank are designed to run under pressure not vacuum therefore they can suck air. Even if you bent the fitting just a little and it get's a little too cold, it will distort the crappy snap connector enough and allow it to leak. More Stupid Bean Counter Engineering.
The best solution would be to pull the tank, get rid of the fuel pick up line inside the tank, replace it with a 1/2" stainless steel line, and then neck it down to the 3/8" hose size before you go into your Kennedy pump. Dodge Cummins trucks have a lot of aftermarket kits to do this trick. If that is too much for you, remove the plastic snap fitting line and replace it with a hose with good all stainless steel worm clamps.

Design a Bean Counter Engineer Target for the rest of us to use so we can shoot it with our weapon of choice.
That way you can spare your CRD.

bugnout · **Posted:** Fri Dec 10, 2010 11:48 am

The two flexible metal lines to the top of the fuel tank have been known to leak air. I replaced mine with hose and clamps.

You need to drop the tank, which is not a big deal (unless its full)

craneman · **Posted:** Fri Dec 10, 2010 11:58 am

The suply line did have the connector cut out and i installed rubber line to accomidate my fuel pump. are you saying there could be a connector at the tank that might leak? even so i would think the kennedy would eliminate that air pocket when it starts up and runs for 20 seconds. obviously im wrong but the logic seems to be there. my next thought was to get a new filter from the stealer and git rid of the raycor, but i hate to waste the money. something tells me thats where the air gets in but not sure.

reka12 · **Posted:** Fri Dec 10, 2010 12:11 pm

When I installed my lift pump, I neglected to tighten the hose clamp on the suction side. The vacuum produced by the pump allowed air in the line and the pump would move it to the fuel filter. I had similar issues, periodic hard starting and in one case, stalling. I was going to check the pressure coming into the filter at which time I disconnected the inlet side of the filter and while messing around, noticed a few small bubbles passing through. I traced it back to the hose clamp. No problems since.

Also, the Kennedy pump will act as a "pass through" or open fuel pipe if it is not working. You may not even know if unless you check it.

craneman · **Posted:** Fri Dec 10, 2010 12:27 pm

thanks for the thoughts. the pump is definatly sending fuel. i did unhook the connection at the fitler and turn it on, i got plenty of fuel. i will double check my connections back at the tank.

BlackLibertyCRD · **Posted:** Fri Dec 10, 2010 10:12 pm

Here is another thought. The original fuel head has a check valve to prevent fuel from draining back to the fuel tank when sitting. It could be as simple as a missing check valve in your setup.

geordi · **Posted:** Sat Dec 11, 2010 12:14 am

It does sound like a check valve issue, fuel drainback. I have an external pump at the tank, and even before installing that pump, I wasn't having any problems with fuel drainback while sitting (stock fuel head - old design) I was having fuel delivery problems through the filter media. At high demand, suction alone just wasn't cutting it.

There is an external check valve that you might think about getting, if there isn't any way to put one on the Racor - Search for the FLMAN Transmission Mod.

bugnout · **Posted:** Sat Dec 11, 2010 11:37 pm

I have the Racor 245 and have no problems with drain back. Don't think it has a check valve. Not sure the stock unit has one either.

geordi · **Posted:** Sun Dec 12, 2010 1:37 am

Well if there is an air leak at or after the filter, the fuel might have be able to drain back to the tank... But if it only runs for 10 seconds, that also suggests either an air pocket forming in the line (from the leak / drainback) or maybe the pump isn't activating instantly? Do the Kennedy pumps have a pressure cut-out switch on them?

Even if there was an air leak at the tank, the engine should run longer than 10 seconds before it inhales the bubble. 10 seconds is about what you might get from just the line to the filter, and maybe a little from the filter. The engine doesn't need much fuel, but don't forget that the gear pump (low pressure supply) is inhaling a LOT more than the engine needs, and passing it right back to the tank.

Stupid question, but just in case... You have checked that you have the filter connected up in the right direction, right? If it is backwards, there is a possibility that it could be pulling a check valve closed toward the engine, and that is what starves the engine for fuel. I'm guessing here, I can't logically explain how that could happen, yet the engine be able to run longer after simply priming the system.

Wait a sec. You said it runs after you pump the air out after it stalls. Is this correct? How are you pumping the air out, if you have a Racor head? Are you somehow still using the stock priming button?

KaspinCRD · **Posted:** Sun Dec 12, 2010 4:50 am

geordi wrote:

Wait a sec. You said it runs after you pump the air out after it stalls. Is this correct? How are you pumping the air out, if you have a Racor head? Are you somehow still using the stock priming button?

The Racor has a built in primer pump, just like the oem setup.

geordi · **Posted:** Sun Dec 12, 2010 5:14 am

Oh, I didn't know that. Is it possible that there is a problem / loose part in the primer head? That would certainly be an easy spot to let air back into the system.

dkenny · **Posted:** Sun Dec 12, 2010 8:46 am

while my suggestion wont help with the leak problem it will make bleeding easier.

if you notice the Racor head has 2 outlets.
one runs to the CP3, the injector pump
run the other one through a valve then to a 'T' in the return line.
to bleed just turn on the key and open the valve..bleeding made easy. just remember to close the valve

-dkenny

craneman · **Posted:** Tue Dec 14, 2010 5:26 pm

All of this data i will take into consideration. BUT, quite honistly i have tried most of what you all have suggested. i do have an inline check valve right at the inlet of the filer. in fact i work for a generator service company and we stock a nice 1/3psi open pressure check valve that i have used. still getting the air somewhere. i startted her this morning as it was about +10 here, for the wife and sure as hell she did not let me down. stalled shortly after start. this weekend i did a complete recheck of all of my connections. nothing new was found. and it still sucks, litrally. thanks for all of your input. i know there is an answer out there somewhere. i have not junked her yet.

UtopiaCRD · **Posted:** Tue Dec 14, 2010 5:46 pm

craneman wrote:

thanks for the thoughts. the pump is definatly sending fuel. i did unhook the connection at the fitler and turn it on, i got plenty of fuel. i will double check my connections back at the tank.

Just a stupid question, but it isn't clear from your wording. Did you check the flow after the filter or before the filter?

FUEL PROBLEMS AND A 50 CAL. SHELL

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