NHC 250 No start-fuel problem

NHC 250 No start-fuel problem *resolved*

*edit* resolved-I blew up the pump by reassembling it incorrectly.

Cranks but no start. Runs on starting fluid.

My fuel system needed some maintance so I replaced the fuel line from IP to fuel filter, completely cleaned canister and replaced filter. I also replaced the clear primer hose and extended the primer petcock down 6" with tubing to make priming easier.

I've checked the manual shutoff and the solenoid shut off and both work properly. I primed it easily using compressed air to the fuel tank. The IP is full and the primer spits out clean fuel with no bubbles. All my fittings are tight.

No fuel is getting to my injectors. The line out the top from the shutoff is dry. I removed the line and when I crank the engine no fuel comes out of the IP.

The TM for crank no starts isn't bad, but I followed through and ended up with notify supervisor.

Any ideas for me?

Thanks!

What did your supervisor say...

That there is funny, brazen, though maybe not to sed.

He said add a pic to my thread. You can see the disconnected fuel line in about the middle. You can see my extended drain valve line on the right, my new fuel line and clear primer tube also.

Is there voltage at the solenoid? Try screwing the little knurled knob in and see if it lights.If it does, you will need to pull the so or unscrew the knob to shut it down.

I also had the IP off to replace a leaking throttle shaft gasket. A new gasket seals the IP nicely and the o-ring fixed my throttle shaft leak! Don't lose that clip! The input shaft into the IP has that bisecting piece of metal that seems to line up with the input into the compressor. I'm pretty sure that lined up correctly as the IP slid right into place.

WillWagner said:

Is there voltage at the solenoid? Try screwing the little knurled knob in and see if it lights.If it does, you will need to pull the so or unscrew the knob to shut it down.

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You bet. Good volts, works properly, had it completely off and apart. A bad solenoid was my first thought after reading many, many fuel threads. But no, works fine. Also tried the manual screw. Screwed it in, same thing, no start. As an aside, with all this messing with my fuel system and the primer, I found an easy way to check the function of both the solenoid and manual screw. With the fuel rail above empty (my current problem) or disconnected, pump the primer and note no air in the line. Now if you manually close the screw or flip on the ignition the valve opens and you suck in air. Test one then the other to see if your solenoid is working properly.

Here's the fuel line going to the injectors. It's disconnected from the IP for troubleshooting. When I crank the engine, no fuel comes out of the IP. Shouldn't it shoot out like a jet?

The fuel only comes out a couple of inches or less but there should be fuel.

did you visibly check that the shutoff is open?

You might take the sensor out that is in the front left side of the pump and make sure there is fuel in the pump. If not use some clean fuel and pour in there till full. When i would change a fuel pump on one like these I would fill it with clean fuel for easier starting. On most of the commercial trucks i have worked on there is just a plug there not a sensor.

JJP said:

did you visibly check that the shutoff is open?

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I did. In fact I completely removed he shutoff and solenoid and exposed the outlet hole on the top of the IP to be sure.

wrenchturner6238 said:

You might take the sensor out that is in the front left side of the pump and make sure there is fuel in the pump. If not use some clean fuel and pour in there till full. When i would change a fuel pump on one like these I would fill it with clean fuel for easier starting. On most of the commercial trucks i have worked on there is just a plug there not a sensor.

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Indeed. Mine just has the plug, no sensor. Removed the plug and filled the IP with fuel. With the IP full and the system primed I'd expect fuel to come out the top immediately upon cranking, but no joy.

Sooo, you had a running truck and took he pump off and apart to repair a throttle shaft leak. the pump was reassembled and now zero delivery? Did you remove the stop from the throttle shaft? Try running it directly from a bucket and see if it lights. If not, take the fuel inlet fitting off and look in the hole at the inlet to the gear pump....use a mirror, if it is a 90 degree fitting you will need to remove the pulsation damper to get the fitting off.....have someone crank the engine and see if the gear pump is turning.

Very good summary. Thanks! Those sound like good next steps. I really need to order me a new Soldier B. Being self sufficient is great and all but extra hands are always nice. I'll report back with the results. Thanks!

I did crack loose the setscrew but tightened it right back up once I realized what I was messing with. Had the shaft spun in there then it might not be lined up correctly and not allowing any fuel to pass? I'm going with 99.9% sure it didn't move so I'll try the bucket method. Which I have no idea what that is. Any tips?

WillWagner said:

Sooo, you had a running truck and took he pump off and apart to repair a throttle shaft leak. the pump was reassembled and now zero delivery? Did you remove the stop from the throttle shaft? Try running it directly from a bucket and see if it lights. If not, take the fuel inlet fitting off and look in the hole at the inlet to the gear pump....use a mirror, if it is a 90 degree fitting you will need to remove the pulsation damper to get the fitting off.....have someone crank the engine and see if the gear pump is turning.

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I have one that ran on ether and haven't diagnosed it's problem yet, but mine is an 8.3.

Was it running prior?

Running strong, no probs except the small fuel leak. It's repair is what lead me here.

sed6 said:

Running strong, no probs except the small fuel leak. It's repair is what lead me here.

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Sorry i can't be more help! If you have made sure your getting fuel at the pump and it's not coming out injectors, it would seem there is an internal problem. But I have not messed with that part of a 250.

My problem with my 250 was the fuel shutoff valve would not stop the engine and I relied on the manual valve. Once apart, the plunger and spring was missing, so the reason was obvious. $55 for a new solenoid valve and it worked great.

Good luck.

Thanks! Yeah, this ones turning into a nail biter for me. Supposed to have it running next weekend to head to Tulsa to get some help repairing my front axle leak. Was out of town overnight so no chance to look at it today. I'll get back at it Monday.

tobyS said:

I have one that ran on ether and haven't diagnosed it's problem yet, but mine is an 8.3.

Was it running prior?

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Just an FYI, Be careful with smelling salts, it can and will hurt the engine very bad.