Hello Everyone,

Got a ?, went out this morn to start My truck, 97,12v, 1ton, and no start. I pumped the lift pump and heard nothing foing to the injectors. This prob started late last year but went away when winter came, now that its warmin up, starting probs again. I just pump the LP a few times and she starts up roughly and then smoothens out. Whenever I pump the LP, i always hear fuel entering the injectors(OF valve), but this morn, nothin, as if the pump is bad. My question, is the pump finally dead, I have owned the truck since new and the LP was never replaced. Trucks got about 175000 miles on it. Any help would be appreciatted.

THANX

 

It sounds like a leak in the fuel system somewhere is causing you to loose prime.

Check all the rubber fuel line hoses for cracking.

 

Thanx Shovel for the reply,

Have searched for leaks everywhere, none to be seen, no wet spots no where. Went out to try again with no luck, a little dark this early morn, flashlight was not cuttin it. I am pumping like a bastard and no fuel is gittin anywhere, about to have a coronary here, its gotta be the LP, You should be able to get fuel or slight fuel, but I'm gettin nothing, not even a pressure build up.

THANX AGAIN.

 

The rubber fuel lines can leak in air without leaking out fuel. If yours are the original lines they are most likely the problem. It's a when not if that they will fail. Make sure they are replaced only with diesel rated hose. Good source here www.fostertruck.com
Doubt if it's your lift pump, the mechanical ones on the 12 valves either work or they don't, you wouldn't be able to pump it up then get it running.

 

Sounds like the same problum I've got warmed up happening again , I got the truck lff this site Jan. 5th , thought that it was looseing prime , had seen a new L.P. under the hood , then the other week the problum came back [ with the ing. on I went under the hood and pulled the linkage from L.P. up it stayed and the truck started , now I think that its the relay , intermitant problums take a persistence.

 

On a 12V there is no linkage on the LP. John Faughn must be meaning the fuel shutoff solenoid on the side of the injector pump. This fuel shutoff could be causing the problem. You can check it by getting in the cab and tap the starter without starting the engine, leave the key in the on position and the plunger in the solenoid should continue to be in the up position, in this position fuel is allowed into the injector pump and when the current is cut off when the ignition switch is turned off the lack of current allows the plunger to fall and the fuel fails to be delivered through the pump.

 

Last Year I went out to swap out the rubber lines, I did the 5/16 return line but didn't do the supply, it looked good and today it still does. Will change it to be sure though, I took the fuel filter out, canister type, and the filter looks whitish, I think that thats good, got bout 20000km on it, I then started to take apart the truck to get to the lift pump. I callled around today for prices, dealer was over $400 cdn list, WOW, cummins dealers were $340 cdn, I'd hate like hell to spend that kind of money and it wasnt the lift pump. When I do pump the plunger, I get some fuel, it will start to fill the filter and then nothing. My shutoff solenoid though is in the down position when I turn the key forward, I manually lift and it stays up, still no start, so seems I might have a solenoid issue too. Any help would be appreciatted.

THANX

 

The solenoid will not lift up until the key is in the start position, it draws it's power off the starter motor.

I think you're sucking air. If you have an air compressor pressurize the fuel tank with a blow gun wrapped in a rag while anther person listens for leaks up front. Don't get carried away and blow up your fuel tank, 5 psi is plenty.

 

Thanx infidel,

I did not kno that, I thought it lifted whan You turned the key forward, thanks for the info, I've just talked to Mark at Pier's and We sent through a few scenario's and it sound that the lift pump has had. Hope to hear more from Yah'll.

THANX

 

OK, sounds like you have eliminated the shutoff solenoid as a potenial problem, scratch one thing off the list.

If you end up replacing the lift pump you might keep Marty T. in mind. He can sell you one for less than $100. Kinda doubt that's your problem though.

If I were you, the next thing I would do is crack the overflow valve at the IP, get a buddy to help you and crank over the motor for no more than 10-15 seconds at a time with 2-3 minutes in between for the starter motor to cool down. It should only take one or two cycles, if you get good steady fuel at the overflow valve your lift pump is functioning. Tighten the overflow valve back down.

Go crack 2 or 3 lines at the injectors and repeat this process until you get good fuel flowing through the lines, be ready to shut off the engine if it tries to start. Tighten the lines back down and try to start it again, if it starts it's going to run rough and smoke until it clears the lines.

I really think from your description you've got a fuel line problem allowing the fuel pressure to bleed off between starts or a blockage in the tank or possibly in the heater/strainer. Have you replaced the filter recently?

Let us know.

 

My fuel filter is good, replaced the LP and connected everything up, still no go, I cannot find any fuel leaks anywhere, but I will now replace the lines from the tank to the pump(return) and to the filter as a whole, gonna bypass all steel, I replaced all rubber and still no start. I'M LOOOOOOOOOOSEIN IT. Whats Me next step Yah Guys tink.

THANX

FXSTS

 

Use the pressurize the tank trick I spoke of above.

 

IF you have happened to lose prime and got air into the system bleed the system and/or injectors as explained above. When you try to start the truck try holding the "gas" peddle to the floor while cranking. If it kicks at all keep your foot to the floor untill it starts (it might run really rough for a few seconds). This is the only way I can get mine going when I get air in the system. Not sure if its the correct thing to do or not but it works for me. If I don't floor it mine will never start.

Might be worth a try.

 

Have you cracked the system at the overflow valve and/or the injectors?

I'm telling you if you are getting adequate fuel at the injectors the thing will start!

The "pressurized tank trick" Infidel describes works like a bandit to get the air out and fuel in the lines, no cranking over the engine until you get good clear diesel at the injectors.

Here's how I did it when I did a bunch of fuel system work to mine and couldn't get it started. I attached a 10 ft. piece of rubber hose on the end of my air nozzle, set my regulator at 5-10 psi and wrapped a shop rag around the hose. Twisted and shoved the hose into the fuel filler neck until it was tight.

You can hit the air from the engine compartment so you can see when you get clear fuel, be sure you let it bleed the air until you get a good clear stream of fuel for several seconds, yes, it will make a little mess but you can go back and wipe up after you get this dang thing started.

I went step by step, making sure I got good clear diesel at each of the following points in the following order, retighten after you get fuel at each point;
1. bleeder screw, top of fuel filter housing
2. overflow valve, to be sure fuel was past the IP
3. 2-3 injector lines at the injectors

Remember, if your truck is getting fuel and air and has enough "humph" in the batteries to spin it over it's gotta start, its just gotta!

Let us know.

 

Well I've completed the job of gettin Me truck back on the road, thanx to Everyone for Your advice and help. It did turn out to be the fuel lines as Yah said Shovel more so than the pump. If Yah think that Your fuel lines look bad, wait till You drop Your tank and have a look whats in behind there, and the two nipples from the sending unit, scarey. New sending unit, brand new lines wright from the tank to the motor, no connections, add-ins, splices etc.... . Once again, Thanx to Everyone.

NO1B4ME