M40 + Walbro 255 = fuel starve?

[Acaciastrain360]

As the title says.... I had an M50 now gone back to M40, but I still have the 255 pump fitted. It runs fine on start up for about 30 seconds and then splutters and dies... Too much fuel pressure? or not enough fuel? Or something otherwise like dirty filter? (Fitted new one 3 years ago, and has been sat the past year in garage..)

[rix313]

The fuel pressure is regulated by the regulator on rail not the pump.

[Acaciastrain360]

The fuel pressure is regulated by the regulator on rail not the pump.

So it's more likely to be the filter or a dodgy regulator?

[daimlerman]

If the engine fires immediately then the rail is retaining fuel pressure,so you have a supply problem.

[Acaciastrain360]

Yeah it starts and runs fine then eventually conks out, so I'll check filters etc cheers

[Acaciastrain360]

So I've put the standard fuel pump in and checked that all filters are clean and it STILL starts lovely and then dies after 30sec-1min! It's getting boring now :/ any more idea So?

[Brianmoooore]

If the pump and filter were fine with the M50, then they'll be OK with the M40, unless something has changed in the meantime. A blocked filter will be immediately obvious if you power the pump briefly with the fuel feed pipe disconnected from the fuel rail.

starts lovely and then dies after 30sec-1min!

What colour are the spark plug tips after it stops? From this statement it looks like a (blue) coolant temp. sensor problem.

[Acaciastrain360]

If the pump and filter were fine with the M50, then they'll be OK with the M40, unless something has changed in the meantime. A blocked filter will be immediately obvious if you power the pump briefly with the fuel feed pipe disconnected from the fuel rail.

starts lovely and then dies after 30sec-1min!

What colour are the spark plug tips after it stops? From this statement it looks like a (blue) coolant temp. sensor problem.

Defiantly not blocked, I've already soaked the garage floor haha... With regards to the coolant temp. Sensor.... Would this have such a major effect on the running of the engine?

[Acaciastrain360]

If the pump and filter were fine with the M50, then they'll be OK with the M40, unless something has changed in the meantime. A blocked filter will be immediately obvious if you power the pump briefly with the fuel feed pipe disconnected from the fuel rail.

starts lovely and then dies after 30sec-1min!

What colour are the spark plug tips after it stops? From this statement it looks like a (blue) coolant temp. sensor problem.

Defiantly not blocked, I've already soaked the garage floor haha... With regards to the coolant temp. Sensor.... Would this have such a major effect on the running of the engine?

I've put a spanking new blue sensor on... Still runs like crap! I cleaned the plugs and put them in and they come out black and sootie!!!! I need help haha this engine sucks!

[Acaciastrain360]

Thanks, yeah I've read other people posts and realised its not the right way about it... I will be getting it plugged in this week too which might help source a fault.