Dealer Starting engine problem, model G

[Lacmullin]

I would check the simplest things first. Key switch and plug. Plugs on back of controller. Look for pushed back pins. Can you post the sn# ?

I really appreciate your help.

The serial number AHG811672.

For the switch, I will try some spray lubricant directly in the switch or better replace it?

To have access to the controller plugs, can I remove only the controller (black part) or have to remove all the grey dashboard on the driver side?

Thanks.

 

[Jabonee]

I really appreciate your help.

The serial number AHG811672.

For the switch, I will try some spray lubricant directly in the switch or better replace it?

To have access to the controller plugs, can I remove only the controller (black part) or have to remove all the grey dashboard on the driver side?

Thanks.

Yes the display can be removed from the dash. There are four lock tabs. Located at each corner of the display. They are accessed from the back side. They are a real pain in the you know what to release! Locate plug J4 pin E purple wire #9330. This is your run circuit signal wire to the controller. :thumbsup:

 

[SSdoxie]

If the dash display powers up properly with key in Run position before cranking and are still on after releasing key from Start then there is no issue in the key switch. Same signal signal through the key powers up the display controller and turns on the engine ECM.
Because it eventually stays running after holding Start position for extended time and starts/runs fine after warm, suspect a fuel flow problem with cold, cloudy fuel. The Bobcat filter is a high efficient filter so if fuel reaches it's cloud point the filter starts to restrict fuel.
When engine is cranking/start mod the pump pressure regulator is fully open (on the pump intact side) will draw max fuel and send excess through return and the Cold Weather by-pass on fuel return is closed sending warmer return fuel directly to intake of the filter to warm fuel at the filter. When key is released to Run position the ECM controls the pressure based on engine RPM, so thick cold fuel will act just like running out fuel.
Try warming the fuel filter and adding fuel additive to lower cloud point temperature.

 

[LouNY]

Reading SSdoxie's post I assume that you have a common rail system so no fuel stop solenoid to act up. Does that engine have glow plugs or an intake manifold heater.
If it only happens when it's quite cold the manifold heater may be shutting off when the key is released.
I have seen many times on the older engines when they needed to be carried with the starter for several seconds in order to run, they would actually start but cold fuel and cold intake air would almost snuff the fire out in the engine for awhile.
I have seen several times when activating an intake heater while first running allows an engine to run smoothly after several seconds.

 

[ruffdog]

I wonder if there is a pressure switch in the fuel system? Does the lift pump have to get to a certain pressure before it will attempt a start? Just throwing this out there before I look at a manual.

 

[Jabonee]

I wonder if there is a pressure switch in the fuel system? Does the lift pump have to get to a certain pressure before it will attempt a start? Just throwing this out there before I look at a manual.

No lift pump. T4 engine has 2 stage pump controlled by an IMV. If there were fuel issues he would be getting ECU trouble codes. :thumbsup:

 

[Jabonee]

Reading SSdoxie's post I assume that you have a common rail system so no fuel stop solenoid to act up. Does that engine have glow plugs or an intake manifold heater.
If it only happens when it's quite cold the manifold heater may be shutting off when the key is released.
I have seen many times on the older engines when they needed to be carried with the starter for several seconds in order to run, they would actually start but cold fuel and cold intake air would almost snuff the fire out in the engine for awhile.
I have seen several times when activating an intake heater while first running allows an engine to run smoothly after several seconds.

A fuel issue was my first thoughts too but once the engine reaches about 900rps like the excavators the starter disengages regardless of the key position. FYI known issues with key switches in both 5600 and MTs. :thumbsup:

 

[ruffdog]

I wonder if the key switches are the same "brass tabs that ride on top of copper contacts" design? I have seen the grease they put in those gets stiff from age or cold. The brass tabs can crack and the little springs can break too.

 

[Lacmullin]

No lift pump. T4 engine has 2 stage pump controlled by an IMV. If there were fuel issues he would be getting ECU trouble codes. :thumbsup:

Hi Jabonee, you mean if mi fuel was freezing in the filter or the line, i should read a code on the control panel?

Because it is a early model G (september 2014) with the Doosan motor, I verified and the fuel by-pass have been done by the dealer on this engine when the toolcat had 500 hours.

I also verified with the past owner ( I have this machine since a week), and he told me that he had the same problem even if the toolcat slept in the garage. He had to hold the key 4-5 seconds in the starting position before he release the key very slowly to the running position. The dealer had check everything and they said it was normal since this model of control panel usualy work with keyless!!!!!!!!!! Very strange!!!!

Very very confusing..........and by the way, everything run just great when the toolcat ran for 15 minutes, it start like a champion!!!!!

 

[ruffdog]

OK...I get it now. The machine starts fine, but if he releases the key from the start (cranking) position to the RUN position, the engine quits. If he waits or slowly moves the key to RUN, then the engine may stay running.

OK, is there a sensor that should read that the engine has started, but, for some reason when cold, it is slow to react?

OR, when warm in the cab, does the ignition switch operate as it should?