Cat 950g (3126 mech) wont stay running

[GCC]

Ok got a 950g with a 55k prefix 3126 engine its the mechanical version. It was running great driving along, and then it started to stumble and loose power. It just had new injectors put in it couple hours before for same issue. Had cat set the overhead, so now soon as you turn the key it fires right up for a split second and dies instantly. Its almost like u turn the key back off as it fires, put new filters on it no difference. Trying to find a way to test the fuel shut off solenoid, also hand primer is good and hard if after a start and die.

 

[ahart]

Here’s the systems operation of the fuel shut off solenoid according to SIS, from the sounds of it, you’re losing power to the shut off solenoid but will need to test to confirm.


The fuel shutoff mechanism is activated by an energize-to-run (ETR) latching solenoid. A spring loaded plunger inside the solenoid acts on a lever assembly within the front housing of the governor. This lever assembly pushes the governor output shaft to the FUEL OFF position when the plunger is released electrically or the plunger is released manually at engine shutdown. At engine start-up, the solenoid is energized in order to latch in the run position. The governor output shaft is then free to move to the FUEL ON position.

Engines that are equipped with a latching solenoid can be manually shut off by pushing button (1) inward. The solenoid CANNOT be manually latched in the run position in order to start the engine.

 

[ahart]

Here’s a schematic for the fuel shut off system

 

[GCC]

So a momentary pulse push’s the button out and latch’s allowing fuel to flow. Then a momentary pulse release’s it to closed position

 

[Nige]

See Page 7 of the attachment.
If you post a machine Serial Number you're welcome to an electrical schematic. There are a few options and it depends on Serial Number.

 

[GCC]

3jw02890 is there anything else that would cause start and diesel instantly and if u keep rolling engine it will act like its trying to fire but not enough fuel. I pulled return line off and lots of fuel coming out.

 

[Nige]

Keep an eye on your messages. A schematic is on the way. I suggest that you test the stop/run solenoid operation before proceeding further.

 

[Nige]

Here's something that may help. A document explaining how the run/shutoff solenoid operates, and how to troubleshoot it.

Also the resistance specifications of both sides of the solenoid.

 

[Nige]

So did you get to the bottom of what was causing the issue.?