case international

tractorjoey

can anyone help me? i have a case international mxu135 , year 2005, it has a bosch common rail fuel system and the problem is when it gets warm, it wont start again and now it wont start once left overnight, does anybody have any ideas:)

landybeast

Sounds like the diesel is going back to the tank so there is air getting in somewhere, if you pump the manual lift pump before you start it will it fire up OK? what sort of hours is on it ?

tractorjoey

thanks for reply, 5000 hours is on it, we have checked every o ring and fitting, all fine even installed a non return valve but i have a doubt about injectors what you think?

landybeast

Have you had any diesel issues with it? the filters are very fine and shouldn't let dirt into injectors. I presume you have checked the beloved water sensor, the olives on the fuel line can go but the plastic fuel lines can crack, even down in the sender unit in the tank does the level in the tank effect it. Did you get it plugged it it will show the pressures on the injectors and how fast the main pump is keeping up with ecu inputs ? When running whats it like power ? smoke?

JohnBoy

Assuming all bosch common rail systems are essentially the same then I'd say you could have an issue with the injectors.


Common rail injectors work by holding back the flow of diesel, and when they get a signal they open to inject. the leak off pipes take away excess from the injection process.

when the injectors wear they allow fuel to leak past when they're supposed to be fully closed.

The injector pump on a common rail system is technically a much simpler device than a traditional pump, it just has one high pressure output.

For the engine to attempt to start the ecu needs to sense a certain minimum pressure in the fuel rail (the high pressure line to the injectors) but because the injectors are letting too much diesel out the leakoff ports then injector pump fails to reach this pressure at starter motor speeds.

Give it a shot of easy start and see if it will start and stay running. it should as when running the injector pump is being driven fast enough to overcome the leak back.


We had this issue on a bmw 320d which also has a bosch common rail system (and like I say they're basically all the same) initially only a problem starting from warm, but eventually failed to start completely, but would go on a sniff of easy start.

Common rail fuel systems are not for diy repair, the diesel is under astronomical pressures and a leak/cracked open joint is capable of injecting diesel straight through your skin, which can be fatal.

tractorjoey

JohnBoy wrote: »

Assuming all bosch common rail systems are essentially the same then I'd say you could have an issue with the injectors.


Common rail injectors work by holding back the flow of diesel, and when they get a signal they open to inject. the leak off pipes take away excess from the injection process.

when the injectors wear they allow fuel to leak past when they're supposed to be fully closed.

The injector pump on a common rail system is technically a much simpler device than a traditional pump, it just has one high pressure output.

For the engine to attempt to start the ecu needs to sense a certain minimum pressure in the fuel rail (the high pressure line to the injectors) but because the injectors are letting too much diesel out the leakoff ports then injector pump fails to reach this pressure at starter motor speeds.

Give it a shot of easy start and see if it will start and stay running. it should as when running the injector pump is being driven fast enough to overcome the leak back.


We had this issue on a bmw 320d which also has a bosch common rail system (and like I say they're basically all the same) initially only a problem starting from warm, but eventually failed to start completely, but would go on a sniff of easy start.

Common rail fuel systems are not for diy repair, the diesel is under astronomical pressures and a leak/cracked open joint is capable of injecting diesel straight through your skin, which can be fatal.

thanks for reply, it was very helpful, we have removed injectors and they are sent off to an auto diesel shop to be checked, will let you know how i get on