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Topic: Detroit Diesel Fuel/Starting (Read 503 times) previous topic - next topic

Detroit Diesel Fuel/Starting

An urgent request for input from Detroit operators:

A week ago I was in a hurry to move my coach from storage to a shop. I had been running my genset and don't trust my fuel guage. I added 5 gal of fuel from a can that I filled at a station with a mismarked fuel pump. In haste, I put about four gallins of regular gasoline in the tank which I estimated to be at or below 1/3.

I drove to the shop, no problems; picked up the coach today and drove home—15-mile roundtrip. Engine started and ran fine. I ran my genset for perhaps 2.0 hours this afternoon charging new house batteries. Two main engine start attempts failed, i.e., engine fired then quit. I stopped to troubleshoot and that is when I noticed the gasoline in my gerry can.

Could this acct. for non-start problem?

It is also possible that main tank fuel is low, but I discount this because gen was still running, and it is the engine that is on the low-fuel switch.

Any advice greatly appreciated.


1989 Foretravel U300 Grand Villa
Build #3410

Re: Detroit Diesel Fuel/Starting

Reply #1 –
Quote from: RandallBrink –
It is also possible that main tank fuel is low, but I discount this because gen was still running, and it is the engine that is on the low-fuel switch.

That is the way it is supposed to work but needs to be verified as I have seen more than one coach that was hooked up with the generator on the low point pick up.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Detroit Diesel Fuel/Starting

Reply #2 –
Ah, well in this case I hope you're right about the low-fuel part of it.

As to restarting, I'm tempted to add diesel and try again. As I said, it ran fine when I parked just two hours earlier.

Thanks very much!
1989 Foretravel U300 Grand Villa
Build #3410

Re: Detroit Diesel Fuel/Starting

Reply #3 –
Change your fuel filters. The filters are suppose to stop gas. You may want to drain your tank and start over with fresh diesel.
I had this problem when the separation panel of a fuel truck broke and we got gas in the diesel. We drained all the fuel out of the equipment replaced all the filters and that solve the problem. If you don't want to drain your fuel get extra filters. There is also
fuel polishing which will clean the fuel. Good luck
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Detroit Diesel Fuel/Starting

Reply #4 –
Thank you. I will start with the filter change, as I only got about 3 - 4 gal of gasoline into the tank. I'm now inclined to think its low fuel and unlevel toward the tank.
1989 Foretravel U300 Grand Villa
Build #3410

Re: Detroit Diesel Fuel/Starting

Reply #5 –
I think the gas mixture is messing up the ignition flash point for the engine for a cold start.  In the 70's I remember a fuel supplier putting gas into the underground tank for diesel. The fix was to just add motor oil to the mixture for the amount of gas added.  No issues back then with any of the diesel equipment.
Here's link of someone else doing this more recently: UNLEADED GAS INTO DIESEL TANK -- THE FIX??? - General Discussion - Antique...
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Detroit Diesel Fuel/Starting

Reply #6 –
DD 2 cycles may be different, maybe Pierce will chime in on this, but if it were a cummins (mine) I would fill the tank with diesel and run with it. Only 3 or 4 gal in a 148 gal tank......... About a 40:1 ratio?
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Detroit Diesel Fuel/Starting

Reply #7 –
Thanks to all—I believe the panic was premature and caused by a series of coincidences. 1. The first was using a previously-designated diesel fuel pump that was still marked in green despite now being a gasoline pump; 2. Miscalculating fuel level and then running the genset with low fuel—never again; 3. The coach was parked laterally level but with an approximate 2-3 degree longitudinal list at the curb, to the right and away from the fuel pickup. I believe it was just enough to briefly cavitate at the fuel delivery pickup, thus causing the start failures.

I manually added 10 gal diesel and it fired right up. I will add more fuel manually in the morning, then off to the truck stop for full fuel.

Thanks again to all who answered the anguished call.
1989 Foretravel U300 Grand Villa
Build #3410

Re: Detroit Diesel Fuel/Starting

Reply #8 –
 As you have found out due to tank size, angle of how the coach is setting, and fuel gauge being inaccurate can leave you in the walk mode. Glad you got this part figured out. A good rule of thumb is never play the low fuel guessing game with one of these coaches. This is the reason we always fuel at the truck fuel deck. Now days even there you have to make sure that you don't use the DEF hose.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Detroit Diesel Fuel/Starting

Reply #9 –
If I was going to use that fuel with the gas I would definitely put in a double dose of fuel treatment to lubricate the fuel injection
pump.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Detroit Diesel Fuel/Starting

Reply #10 –
Back when I imported diesels, Mercedes allowed up to 25% gasoline to be added to the diesel in very cold weather. It won't hurt anything.  The tank hoses could be backwards or a low tank might introduce air into the system from fuel hoses that are starting to go south.

Detroits 2 cycles don't have a main fuel injection pump like other diesels but rather have a pump and injector combination (unit injector) at each cylinder. This is what the extra lobe on the camshafts is for.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Detroit Diesel Fuel/Starting

Reply #11 –
I will certainly add the additional fuel treatment. Thank you.
1989 Foretravel U300 Grand Villa
Build #3410

Re: Detroit Diesel Fuel/Starting

Reply #12 –
Thanks Pierce, I am greatly relieved to hear that this will pass with the refueling.
1989 Foretravel U300 Grand Villa
Build #3410