MF 431 - Injection pump problem? - sat and then fires off to high rpm

[Jason1010]

It's not rebuilt. For much of the tractor life, it was not routinely used, but was regularly started.

In 17 years, it would start on first crank. It has been used much more within the past few years with no issues. When I moved it to the shed it's in now, it ran fine. Throttle responded and it idled down fine before I shut it off.

Fast forward a few months with no start and then description of issue in 1st post.

 

[Jason1010]

This is also one of the newer Perkins designs.

Tier 2 compliant. Looks like half the injection pump screws are tamper proof.

They have packed everything together real tight under the sheet metal...

 

[Jason1010]

Update to this thread.

Tractor is now up and running again.

Short version, the injection pump had rust and trash in it.

The long version is that removing the injection pump and injectors on a MF 431 (and the similar 461) will entail removing all the sheet metal, steering wheel, dash, fuel tank, fan and radiator. This is just to get to the front timing cover and injectors.

Then water pump comes off, then timing cover. Rotate engine to TDC. Pin the engine. Loosen injection pump nut, lock pump. Remove timing gear and then remove pump.

Took pump and injectors to a Delphi authorized rebuilder and they went through both.

For those with this model MF and a Delphi pump (does not apply to Bosch equipped models), bleeding the air is supposed to be done with the lift pump on for 3 minutes. However, I did have to crack the injectors and crank. But it actually didn't take much cranking before it fired off. Since I had the fuel tank off, the fuel pickup and return were run to a jug of diesel.

Once the fuel tank is on the tractor, you cannot access the injectors. There is an injector cover and the fuel tank that prevents access.

 

[thepumpguysc]

Thank you for the update, much appreciated..