Mustang MTL25 - Hard to Start

[631G]

We have a 2006 MTL25 skid steer that we recently put a long block into. Since we performed the swap, the machine has run great. However, recently we started to have issues cranking it up as the temperatures cooled off. What we have found is that when you crank up the machine in the AM you have to turn the motor over for about 45 seconds before it hits. During this time the exhaust smoke is white and pretty heavy. Once it hits all the smoke clears immediately and the machine runs great. From here on you can shut down the machine and restart easily unless you let it sit for more than an hour or so and if you do then you're back to square one just like it was at first start in the morning.

We have replaced the electric fuel pump, cleaned all the fuel filters along the line from the tank to the motor and that has helped some but the issue persists. Could this be an issue on the main injector pump allowing fuel to leak back thus starving the injectors of fuel until the pressure returns back to normal and any air clears the lines? Would this be a pull the injector pump and send out to be rebuilt?

Model: MTL25
SN: 21503272
Hours: +/- 4650 (+/-100 hours since engine replaced)
Engine: 4TNV106T Yanmar

 

[skata]

Are you turning the key counterclockwise first, and hold it for 15 seconds? That's the preheat.

 

[631G]

Are you turning the key counterclockwise first, and hold it for 15 seconds? That's the preheat.

Yes. What we have been doing is cycling the electric pump twice and then hitting the preheat to start the engine

 

[skata]

Have you checked for voltage at your glow plugs to verify they are getting power?

 

[631G]

Have you checked for voltage at your glow plugs to verify they are getting power?

Yes we have heat at the glow plugs. I think that for what ever reason we are loosing fuel to the pump or its leaking back and so each time we have to start the machine its like its the first time your firing it up after changing fuel filters?

 

[skata]

Yes we have heat at the glow plugs. I think that for what ever reason we are loosing fuel to the pump or its leaking back and so each time we have to start the machine its like its the first time your firing it up after changing fuel filters?

Check your fuel filters or bowl orings.

 

[heymccall]

If there is white smoke right away, the glow plugs or grid heater (if equipped) isn't working.

 

[Nige]

Heavy white smoke that makes your eyes water while the engine is cranking is an indication that you have plenty of fuel but not enough heat to light the fires.

Start looking at the preheat system would be my suggestion.