P38A Hot fix was working not now

The hot fix relay was working ok that I fitted 3 weeks ago until yesterday glow plug light came on as usual but just kept cranking until I had to get green flag to help me out wonder if it's got anything to do with the hot weather

gazdon said:

The hot fix relay was working ok that I fitted 3 weeks ago until yesterday glow plug light came on as usual but just kept cranking until I had to get green flag to help me out wonder if it's got anything to do with the hot weather

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You must wait for the glow lamp to go out before cranking. Possibly not the hot fix, check for air in the clear pipe from filter to injection pump and for function of lift pump.

In tank pump if tank low on fuel ...

I always wait for the light to go out before starting there is air in the fuel line what could cause this fuel filter seal maybe

gazdon said:

I always wait for the light to go out before starting there is air in the fuel line what could cause this fuel filter seal maybe

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Fuel lift pump has died and the injection pump is sucking air past the O'rings in the filter head maybe. Check the function of the lift pump as advised earlier. Way to do it is described in Tech Archive. Check that fuse 39 is sound and also relay 12. If you remove relay 12 and take a positive feed from the battery and touch relay 12 socket pin 5, the one that is contrary in orientation to the other three, you should see the air start to move along the pipe if the pump is sound.

Even considering the temperature up north I would expect a diesel to start not needing glows this time of year.

Do you keep it in a fridge overnight?

When were injectors last serviced.

pete1987RRC said:

Even considering the temperature up north I would expect a diesel to start not needing glows this time of year.

Do you keep it in a fridge overnight?

When were injectors last serviced.

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The M51 always needs glows from cold, because of their meager start fuelling, they just don't come on for as long when it's warm weather. Tired injectors can play a part in starting issues though.

Ok great will check lift pump next I have just changed the fuel filter as it was looking in very poor state when I emptied the old filter it was full of brown sludge and water in the diesel I have run the engine and no air in the pipes at the moment

Check leakoff pipes on injectors .as fuel will run back to tank and let air in ...

Still getting problems it starts fine from cold and after driving for a little while it will start again no problem but when warm it will not start the hot fix relay must be doing it's job as the glow plug light comes on cold or hot the only way I can get it to start is to poor water over the injector pump

gazdon said:

Still getting problems it starts fine from cold and after driving for a little while it will start again no problem but when warm it will not start the hot fix relay must be doing it's job as the glow plug light comes on cold or hot the only way I can get it to start is to poor water over the injector pump

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Did you check the function of the lift pump?

This thread sounds familiar Wammers.

Buzz2406 said:

This thread sounds familiar Wammers.

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Yup sure does.

wammers said:

Yup sure does.

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Thanks just checked the lift pump by connecting a wire from the battery to relay 12 and pin 5 which I think is the bottom one nearest to the ecu and nothing happened so looks like I need a lift pump then or cam they be fixed

gazdon said:

Thanks just checked the lift pump by connecting a wire from the battery to relay 12 and pin 5 which I think is the bottom one nearest to the ecu and nothing happened so looks like I need a lift pump then or cam they be fixed

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Can't be fixed new pump needed don't get a cheap one VDO OEM. Like this. http://www.island-4x4.co.uk/fuel-pump-esr1111g-p-7733.html Of course you can get it from where you like but that is what you need. DO NOT buy the cheap ones.

Also where is the lift pump situated please

gazdon said:

Also where is the lift pump situated please

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In the fuel tank.

How does the lift pump work does it work when engine is cold and warm regards Gareth

gazdon said:

How does the lift pump work does it work when engine is cold and warm regards Gareth

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On a pre 1999 model lift pump runs when glow plugs are lit or when engine is running. On a1999 model and on lift pump also works whilst cranking. That was an attempt to cure a hot starting problem. The hot start tricks the ECU into thinking the engine is cold. The ECU then turns on glow plugs, runs the lift pump and sets cold start fuel to aid hot starts. Hence it's name.