5105 Starting Problem

[texstrk426]

A few months ago I posted a thread about starting problems with my John Deere 5105 all-wheel drive tractor. We mistakenly had put some gasoline in the fuel tank. I finally determined what the problem was after repeated difficulty getting it to start and then drained the fuel tank and put new fuel in. The injector pump had to be primed several times before it would start. It has been stubborn to start ever since and lately with the cold weather it simply will not start. It cranks fine at normal cranking speed. I have not primed the injector pump lately to see if that would cure the issue. I have a suspicion that the injector pump is the issue because once the engine started in warmer weather it ran OK.

Is it more likely that the injector pump will get damaged by having gasoline mixed into the diesel fuel or is it more likely the engine has been damaged to the point it is going to have to have the engine rebuilt? I tend to think it is the injector pump, but what about the injectors themselves?

Joe

 

[Tx Jim]

Did you use ether as as a starting aid when diesel was diluted with gasoline? Only way to know if injectors are faulty is remove them & have them pressure tested. I doubt diesel diluted with gasoline ruined injection pump but stranger things have happened.

 

[texstrk426]

The tractor was operated for probably 30 minutes to an hour with the presence of gasoline in the fuel before it bogged down and stopped. There was toward the end of that time some clattering or pinging going on. At the time I did not know what was wrong. The problem of hard starting became worse as colder weather came about. The last time I tried to start it (last week) it cranked and cranked and no amount of throttle movement or pumping of throttle would get it to fire.

Back when the contaminated fuel had been removed from the tank and new diesel fuel added, I had to prime the injector pump the several times before enough of the gasoline was cleared from the lines as well as the injectors before the engine would start. I used the procedure in the owner's manual. My suspicion is that the cold weather has caused some parts in the injector pump to shrink just enough that there is poor or low pressure going to the injectors. I may be wrong. I have no gauge to measure the injector pump pressure and perhaps I need to have my dealer send a man out to test the unit and make a diagnosis.

Is there also a test for engine compression by removing injectors and testing each cylinder? I would think so. That would be another means of evaluating the situation.

Joe

 

[jd110]

You can check compression by removing injectors and using a proper adapter in injector bore. Before you get that involved, you should check to be sure you have 12 volts being supplied to the injection pump wire on top when key is on. If you do, definitely go through the procedure of bleeding out the fuel. Loosen the 17mm line in the center of the rear of the pump and then pump the primer button on top of the filter until you get good fuel flow at that fitting. Then tighten that fitting and loosen the other lines on rear of pump going to injectors. Crank the engine until you see good flow of fuel spurting out of each line. Tighten the fittings and then crank for another 15 or 20 seconds and engine should start. If you have fuel supplied to pump and voltage supplied to pump, you should get fuel to pump out when cranking. If not, then injection pump may be damaged. Since you have had engine running since the gasoline was in it, I doubt the pump is damaged now, but it is possible.

 

[thepumpguysc]

If the engine is running, chances are the inj. pump didn't get harmed..
IF you had enough gas in the system to dilute the diesel fuel to harm anything.. it would have seized the pump & or injectors..
Both rely on the fuel for lubrication..
MY thought is the "lift pump".. it has a rubber diaphragm in it.. you know what gasoline does to rubber..
They're only $40.00 & well worth the swap.. rather than the $1000.00 inj. pump.
Good luck & keep us posted.. TPG

 

[Tx Jim]

How long was engine run since gasoline diluted diesel was exchanged for good diesel? Before I spent the money to check injectors or compression I'd try to get engine started then run it for an hr or more. Once it had been established that IP has a good fuel supply if it was my tractor I'd attempt to "tow start "it because I think 5105 has no hyd drive function .

 

[texstrk426]

The tractor was used to mow some property for more than an hour after the events that led to it having the gasoline in the fuel. Therefore the injector pump may be OK. However, I need to do as was suggested; check for the 12 volts at the injector pump, then go through the bleeding procedure for the injector pump input and then for the injector pump output lines too. As to pull starting the tractor, I do have a Dodge pickup with the Cummins diesel and a heavy duty chain with hooks that I could use to do that if it becomes necessary. I don't think this tractor has an extra fuel pump in it. The line comes from the tank directly to the fuel filter where the manual bleed pump resides in the line going to the injector pump. I will double check to make sure though.

Thanks to all of you for your help! It will be a while before I get around to further tests. It is very cold this week with temperatures going down into the teens overnight and staying below freezing all day. Brrrrrrrrrrrr!

Joe

 

[thepumpguysc]

Google JD 5105 lift pump & see if 1 is in your system.

 

[jd110]

The 5105 has no lift pump.

 

[Tx Jim]

texstrk426
The reason I suggested "tow starting" is that I once owned a tractor that when it was accidentally run out of fuel due to none operating fuel gauge was very difficult to get started even after intensive bleeding BUT I would tow it not over 5-10 ft and it would start right up. If you decide to attempt to tow start it utilize a higher speed gear.