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Engine dies

This afternoon it was in the mid 50's so I decided to see if the engine would start. I turned on the boost switch first and started cranking. At first nothing happened, but after several tries it tried to start, so I kept at it. Eventually it lit, but quit within a few seconds, and wouldn't get over about 500 rpm. A couple more starts and I was able to hold it at 1000 rpm for a minute and then it would die. I'm guessing that maybe some fuel may have gelled and hasn't completely thawed out yet, but I may be way off on that guess. The weather guessers are now saying mid 60's tomorrow afternoon, so maybe by the time we get back from church it will be warm enough to run. At least I was able to get the air up enough to level the coach.

Re: Engine dies

Reply #1 –
David, try priming before you start cranking, may be air in line due to expansion / contraction of stuff during cold snap.
Good Luck
Gary B

Re: Engine dies

Reply #2 –
As Gary says, use the hand primer. Fuel may have jelled. It should pump easily for a few seconds and then pump harder. Once you feel resistance, keep pumping for another minute.

In case you have not used the hand pump, it's down on the frame on the right as you look into the engine compartment. Push in on the black knob, rotate until it releases and then pump. In case it doesn't work, you may have to pull the plunger and replace the two O rings. About $0.10 each at any NAPA store.

Usually in cold weather, it will run down a couple cylinders for a few seconds and then take up to a minute or so to pick up the last cylinder. Smokes a lot until all six are running. Would plug in the block heater too but shut it off before you try to start.

Don't crank too long as it is easy to melt one of the battery connection terminals in cold weather when it doesn't start right up. I usually start ours with foot off the throttle and then after it runs for a few seconds, use just a little throttle to bring up the RPM to 1000 until all six are going.

Once you get it running, go to the store and buy a diesel additive for jelling. Run both the main engine and generator for a few minutes to circulate the additive before you shut it down. Winter has a ways to go. Adding diesel formulated for winter or #1 diesel (in some places it's called premium diesel) can make starting easier in the cold.

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

Re: Engine dies

Reply #3 –
On DDC engines that have lost some or all of the prime, once you get it started on any cylinders, hold the throttle way above idle, say 1500-1800 rpm until it either runs smooth or dies.  50f , you do not have jelled fuel.
Watch heat on starter with those long crank periods.
Also at 50f, the engine should start right up nice & sweet, it not, you need some attention to filters, pump or lines as in leaks.
A proper setup DDC can sit for months and start right up just as if it had just been shut down.
Dave M

Re: Engine dies

Reply #4 –
We'll see what tomorrow afternoon brings. Pierce, thanks for the tip about where the hand pump is located. That will be the first thing I look for tomorrow. Dave, the engine hasn't run at all in a couple of months, so I'm not surprised that it didn't start right up. It has been quite cold here lately. I did add some anti-jell stuff to the full fuel tank before it got really cold, but obviously it didn't get much of a chance to work through the whole system.

Part of what I wanted to do was to get the thermostat open so the antifreeze I added would circulate. I put it a new block heater element just before it got cold, and didn't have any antifreeze here. Of course by the time the antifreeze arrived (had to order it) it was COLD. Haven't been able to do much on the coach for a while now.

Re: Engine dies

Reply #5 –
Repeat, sitting for months should not be an issue UNLESS you have a leak allowing fuel to run back to the tank or on ground.  It takes a secure plumbed fuel system to hold for months, it just takes TLC & understanding. This is where the guessers start having issues.
A friend has an old back hoe with a 3-71 DDC, sat for over 4 years, put new fresh battery in, started within 10 revolutions.  The biggie issue from sitting a long time is stuck injectors, they stick near wide open, so you remove valve cover and make sure they are all free. Later models have the break away racks, reducing run aways some.  The DDC DDEC Electronic engines do not use the mechanical injectors.

Re: Engine dies

Reply #6 –
Dave,

Was only thinking of jell as a possibility with weather way below zero and the fuel in the tank not up to non-jell temp yet.

Normally, Detroits are instant start with the mechanical engines. I did have a couple of fuel system air leaks in ours after bring it home. Below are a couple of photos. I installed a gauge on top of the primary filter so I could watch the pressure as I used the hand pump. The new check valve and the chassis mounted hand pump are also in the photo. Photo #3 shows the crack that was letting air in.

Pierce

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

Re: Engine dies

Reply #7 –
For sure, am not familiar with the DDEC models as to pressure, but the mechanical units run 65 psi, controlled by an orifice in the return line, the orifice looks like a standard fitting but with closer looking it has a smaller hole thru it, forget the size of the hole, but once you see one, you don't forget them. The 65 psi is the magic number for fuel pressure on mechanical engines 71 or 92 series.  The orifice had stumped more than one wannabee as to why the engine does not perform.
Still the simplest engines to understand and the hardest to start once it is has been run dry of fuel.
 

Re: Engine dies

Reply #8 –
Chances are that the teflon tape and the usual accompanying over-tightening is responsible for that cracked fitting shown in Pierce's pictures.
Rick