fuel problems on the DuraMax diesel

[Capt. Rich]

Hello All, Heading north a few weeks ago we stalled out at the top of the Cumberland Gap on I-24. I changed the filter and bled the system but it still would not start. I called GoodSam and they sent out a mechanic. He was a good old boy that did something I have never heard of but it got the diesel runnung . He soaked a rag in gasoline and held it over the air cleaner. He had me hold the key down until the glow plugs went out. I turned the key and it stumbled for a second and then started to purr. We continued our trip to Wisconsin without a proble. I have had problems in the past where the engine won't start and I have to bleed the system. This time it did not work and his gasoline trick did the job. He said to never ever use ether. Anyone have this problem and thoughts?

[Grumpy]

What filter are you using? Many of us who had 1st Gen SENECA's had problems with after market filters and don't know why. Always used GM OEM.

Never heard of the gas/rag trick, but always carried a bottle of POWER SERVICE (silver bottle) to fill the filter with after a "good ole boy" showed me that trick. Made it a lot easier than using the hand pump to prime the filter.

[CAG]

You don't say what year or if it is in an RV or a Chevy/GM truck but having owned two Duramax trucks from 2004 to 2019 I can tell you that several things cause a crank but no start. One of the first issues is air in the fuel line. The Duramax does not have a fuel pump and the fuel system sucks fuel from tank from engine location. Any leak, anywhere will cause a no start but the major culprit is usually the fuel filter head. O-rings go bad and suck air at that location. The engine will not start. Pumping the fuel pump at the filter head, with the bleeder screw open, until you get fuel out of the screw will prime the pump but the next time you turn it off is will lose prime.

A pump rebuild will usually fix that problem and the very best solution is a "lift pump" installed near the fuel tank. The lift pump (and I recommend taking a look at Kennedy Diesel for the pump, will overcome most all air in the fuel line problem and will show you where the problem is because fuel will be leaking at the trouble point.

This is a good Web site to research your Duramax issues you just need to know which of the many engines you have and go to that Forum.

https://www.dieselplace.com/forums/

Now, to mention another issue. Depending upon the age of the engine, injectors can cause problems, and when they do it is not pretty. There is a simple but not totally accurate way to check injectors and rather than make a long list here I suggest going to the DieselPlace and doing some research.

[Capt. Rich]

It's a 2009 Seneca with the 330 hp DuraMax diesel. A gearhead buddy said I may also be having a venting proble. When I remove the fuel cap it seems to have alot of pressure. Any more thoughts?

[Grumpy]

Originally Posted by Capt. Rich

. When I remove the fuel cap it seems to have of pressure. Any more thoughts?

That was common(actually a vacuum). Never caused any problems that I heard of. The 09 was the LMM series.

[CAG]

It needs that pressure. It is sucking fuel forward. If you every take the cap off and have no pressure look at replacing the fuel cap. It is faulty. I would still be looking at the filter head and again look at a lift pump.

The first time I had a filter head problem I pulled into a gas station in Flagstaff and after fueling could not get the thing started. I pumped up the fuel plunger and it fired up. I finally found the problem later by allowing the engine to idle in the garage. Lo and behold after about 10 minutes one of the O-rings in the filter head opened up and started leaking fuel all over the garage floor. They go bad, get hot and leak fuel.

You can buy the filter kit about anywhere, but someplace like Kennedy Diesel (Duramax) where they know what they are doing is a good place to start.

https://www.kennedydiesel.com/

[Capt. Rich]

Thanks for all the replies. I like the idea of adding a lift pump. Any suggestions for where I would install it?

[TaftCoach]

I hope he passes his knowledge down to the next generation.

[CAG]

Originally Posted by Capt. Rich

Thanks for all the replies. I like the idea of adding a lift pump. Any suggestions for where I would install it?

Generally it installed very near the fuel tank. Be sure that the pump you buy is a flow through type so that should it fail the CP3 will continue to provide fuel and you do not stall out.

[CAG]

Originally Posted by TaftCoach

I hope he passes his knowledge down to the next generation.

The DieselPlace Forum on Duramax has all of this info and more. If you have a Duramax question that is the place to go.