othomas3

My truck died while it was idling Wednesday morning. It sounded like it ran out of fuel. The starter motor cranks and cranks but te truck doesn't run.

This has happened twice before in the past two months. I was on the road the first time and had it towed home. After pumping the prime button for over two minutes it eventually started. Not this last time, through.

Troublehooting so far:

After the second event I removed and cleaned the fuel shut off solenoid and replaced the rotted cover. I also changed the fuel filter. The truck ran fine for about two weeks.

After this last event I replaced the rubber fuel hoses even though they are about 1 year old and looked fine. I again replaced the fuel filter. After pumping the prime button in excess of one minute I tried starting the truck. The fuel shut off solenoid raised as the starter motor turned over the motor but it never started to run.

Any ideas on what to trouble shoot next and what the procedure is for that trouble shooting?

ratsun

Sounds like a fuel delivery problem but?
I know it wont fix your problem but I found if you use Infidels trick of using a spare gas cap that you modify to hook some shop compressed air up to and set your regulator down to 15psi or so you will never pump on that primer again. I use it any time I open the fuel system up and it works like a dream. Back to your problem though is there a chance something is floating around in your tank stopping pick up? Do you have fuel to your injectors? Have you tried cracking a couple of lines at the injectors to bleed any air out?

torquefan

Failed lift pump, or possibly

sucking air, check the electrical connection at the fuel heater first.

With a little ingenuity, you could pressurize the entire fuel system right from the tank forward, and look for leaks. It would also be helpful if you could check the lift pump for pumping pressure and volume. With a gauge, you can test it for inlet suction and outlet pressure.

othomas3

Thanks for the trouble shooting inputs. This bulletin board and all you members are great!

Bought a new fuel tank cap and sacrificed the old one. I "engineered" the old fuel tank cap with a tire fill valve to use in pressurizing the tank.

I'm charging the batteries to make sure I get a good spin from the starter motor.

I'll keep you informed of the results.

othomas3

Pressurized the fuel tank and system using my shop compressor and "engineered" fuel tank cap. No leaks found.

Cracked open the banjo bolt on the bottom rear of the injection pump and had fuel coming out. I took that to mean the fuel is being delivered under pressure from the fuel tank to the injector pump.

Pulled the Overflow Valve and measured the spring. Measurement was .445. Per a Sep 2000 TDR forum article, the measurement should have been .500. I stretched the spring to .550 and reinstalled the Overflow Valve.


Cranked the motor and after two tries the engine started running again. Test drove it for about 15 miles and everything is good. I let it set and tried to start it again and it started right up.

Thanks to Ratsun and Torquefan for the idea of pressurizing the fuel system to check for leaks and not having to push the prime button a zillon times!

Now I am off in cyber space to find an Overflow Valve. I believe TS lists one on their website.

To all my fellow TDR CTD owners, Have a Happy New year!!

ratsun

Good to hear you figured it out.

othomas3

This morning I replaced the fuel injection pump overflow valve. What a difference in idle and acceleration it has made!!!

My low speed islde is smoother and I never thought it was very rough to begin with. My acceleration from a stop has always been jerky and slow. Not anymore! It has smoothed out and is quick. I wish I had done this years ago!!

I had stretched my original overflow valve spring when trouble shooting my truck and it appeared to fix the problem on 1 Jan. When I removed the original overflow valve the spring had already collasped significanty allowing the check ball to roll around.

Does anyone know of a source for replacement springs in these overflow valves?

infidel

I spent a considerable amount of time a few years ago trying so source a spring with no luck. Even turned the search over to my good friend Larry B who is very good at that sort of thing, he didn't have any luck either.

I learned lot about springs in the process though. The size of the spring is the least of the equation. You also need to know the compression force and the material the spring is made from. The material effects the way the spring reacts to heat, something that's very important for a diesel engine.

Many times the spring isn't the only problem though. I pulled one apart where the ball was shaped like an egg from wear. The FP on this truck was all over the place since the ball wasn't always sealing.

You need to be very careful stretching the spring if you don't have a permanent fuel pressure gauge in the cab. Chances are high that you can make too much pressure, the lift pump will put out over 100 psi if you let it. High FP can blow out seals in the injection pump = $$$ or crack fuel lines or the filter.