# Got a puzzle with MX255



## bmoody (Oct 11, 2008)

My MX255 will start up cold and after I let it sit still for 5 minutes or so. However,if I let it run for a few minutes after working it, shut it down and then immediately try to start it....it cranks and cranks before finally "catching". No smoke and no loss of power. Runs great while I'm working. I seldom stop and start like that...it just started this about 12 hrs ago.

Fuel filters have been changed. Dealership mechanic has been out. Fuel checks out ok, he put a new crank**** sensor on it sense that is what the error code said. No go. He comes back first of the week with laptop to check engine more throughly. Got him perplexed.

Anyone have a similar problem? I just have the feeling it's something stupid.


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## chrpmaster (May 5, 2004)

Sorry to hear about your problems bmoody. We can all understand your frustration cause we have all been there at one time or another. I had a similar problem with my Gravely GT last year. It would start well when cold but not when hot. I added some Seafoam to the gas tank to clean up carbon on the pistons and it seemed to help. Still not perfect but much better and for only $6 lots cheaper than a service call from the tech. Let us know what he comes up with because this is a constant issue among tractor owners.

Andy

P.S. Welcome to the Tractor Forum!


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## bmoody (Oct 11, 2008)

Well....alot more complicated than that. Computer fault was fixed, but not the problem. The tech came back today, engine/fuel tests are great. Pressure is where it should be. Shot in the dark, replaced the starter since we looking at things mechanical that cause my tractor to crank slow on second immediate start. No go...out a starter, but that was my call.
Factory, dealer and tech is stumped. At the last sec, we found a dealer installed 4th hydraulic remote that is defective or improperly installed. The way we are thinking is that it is diverting pressure on 2nd start and not giving enough to crank engine since oil is already primed and machine is trying to do 2 things at one time. Pump is being told of two needs and not giving attention to cranking...we suspect a bad check valve. It would never be noticed unless we try to start it two times back to back. 

Thx for the reply.


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## Live Oak (Dec 22, 2003)

Sorry for not getting to this post sooner bmoody. Been having some bee problems. Long story. :argh: 

This may sound weird but it may be something as simple as this. The symptoms you describe sure do sound like fuel starvation due to a vaccum build up in the fuel tank. 

Have you checked the fuel tank cap vent or tank vent to see if a mud dauber has built a nest in the tank vent hole. This little thing can reak havoc. It is worth a look.


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## bmoody (Oct 11, 2008)

Appreciate all the input. Fuel cap is just fine. Tractor has plenty of power, not starving at all. Under ordinary circumstances, you would never notice. Example: Shut the tractor down, walk away for a few minutes and get back on and it starts fine. I can't think of one time I just shut it down and immediately start it again....but it will crank itself to death before starting (on 2nd turn). Crazy.

What the tech is saying is beginning to sound like sense. All on board computer systems say all is well in computer land. We are looking for that peculiar remedy...which if you follow me around...I usually end up with those sort of problems...lol.

We are literally losing cranking power. Electric system checks out ok. Batteries are new, all is grounded. It's the "first time is fine, second and third time goes downhill and let her sit for 2 minutes and she will start up just fine" thing that can't give us a pattern

A head scratcher.


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## Live Oak (Dec 22, 2003)

Has someone actually checked the batteries with a hydrometer and put the batteries under a load test. Bad batteries can raise all kinds so problems on my Cummins 5.9 liter ISB. A bad or shorting cell may not be readily apparent. These newer computer controlled diesel engines have to have a good and steady voltage from the batteries.


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## bmoody (Oct 11, 2008)

LOL. You are not going to believe this. I finished seeding winter wheat Thursday and the tractor was doing the same thing as always. Runs fine, but reluctant to start in second turn of switch.

Tech came this morning to take a remote apart to check the check valve that was diverting hydraulic pressure away from cranking....sure that was it.

As of this morning, can't get the tractor to do it...no problem. Tried every angle for 45 min....starts fine. Dang thing healed itself over the weekend....lol. After a whole fall season of this nonsense...put it away and ba da bing...works fine. 

Maybe I ought to take a weekend off!!


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## cdw (Feb 21, 2013)

Have you had any issues since, I have a MX255 doing the same thing, on the third injection pump.


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