Slow starter

swmeader · Mar 26, 2021

1998 Defender 90
Always started 1st time when one morning didn’t want to start, after 6 or 7 go’s it fires up but then it wouldn’t turn off even when ignition key removed. mobile mechanic has changed the fuel pump solinoid but this morning same thing although it did turn off once a got it started.
Starts perfectly once warmed up.
Nothing to do with battery as it’s new and plenty of power. any ideas out there .... please

Turboman · Mar 26, 2021

swmeader said:
1998 Defender 90
Always started 1st time when one morning didn’t want to start, after 6 or 7 go’s it fires up but then it wouldn’t turn off even when ignition key removed. mobile mechanic has changed the fuel pump solinoid but this morning same thing although it did turn off once a got it started.
Starts perfectly once warmed up.
Nothing to do with battery as it’s new and plenty of power. any ideas out there .... please

Usual diesel starting issues. Glow plugs,Blocked filters or air intake, poor compression, bad injector spray form.

Flossie · Mar 26, 2021

What engine?
If TDI replace your leak off pipes.

bluedog333 · Mar 26, 2021

Sounds like dodgy electrics if it won’t turn off with a new solenoid?

tottot · Mar 26, 2021

bluedog333 said:
Sounds like dodgy electrics if it won’t turn off with a new solenoid?

Solenoid replaced and working he say's.

Air getting into the system, then engine has to turn enough for the pump to self bleed.
Likely places for air to get in and fuel to drain back to tank. Are as Flossie says leek off pipes for the injectors. Fuel filter seal or even a pin hole in the can for those who do not change often enough. Lift pump diaphragm/valves. Less likely are problems with the fuel pipes themselves but any joint can be suspect.

bluedog333 · Mar 26, 2021

tottot said:
Solenoid replaced and working he say's.

Air getting into the system, then engine has to turn enough for the pump to self bleed.
Likely places for air to get in and fuel to drain back to tank. Are as Flossie says leek off pipes for the injectors. Fuel filter seal or even a pin hole in the can for those who do not change often enough. Lift pump diaphragm/valves. Less likely are problems with the fuel pipes themselves but any joint can be suspect.

I understand the starting issues, but how would an air leak allow the engine to continue to run? Genuine question!
Edit... I’ve just read that it now does turn off after solenoid replacement. Doh!

swmeader · Mar 26, 2021

Turboman said:
Usual diesel starting issues. Glow plugs,Blocked filters or air intake, poor compression, bad injector spray form.

many thanks for that

Flossie · Mar 26, 2021

bluedog333 said:
I understand the starting issues, but how would an air leak allow the engine to continue to run? Genuine question!
Edit... I’ve just read that it now does turn off after solenoid replacement. Doh!

The system, in normal conditions, is full of air free fuel. A small air leak doesn't always effect running but can break the vacuum holding the fuel in overnight. Excess cranking is then needed to push the fuel back up to the injectors so it will fire.
Think of a straw with water sucked up it, as long as you hold your finger over the end the water level will stay constant if the straw is full, if your finger allows a little air in, the vacuum will be broken and water will slowly drip out and the level will drop obviously. The highest point of the fuel system is the injectors and or fuel filter, fuel runs away from the injectors and it won't start until fuel is pumped back up to them from cranking.
A common place to let air in is from the spill pipes, cheap and easy to replace, think I paid £4 for a MTR of it from my local indy, even if they look good in situ, as mine did, removing them showed cracks every where.

bluedog333 · Mar 26, 2021

Flossie said:
The system, in normal conditions, is full of air free fuel. A small air leak doesn't always effect running but can break the vacuum holding the fuel in overnight. Excess cranking is then needed to push the fuel back up to the injectors so it will fire.
Think of a straw with water sucked up it, as long as you hold your finger over the end the water level will stay constant if the straw is full, if your finger allows a little air in, the vacuum will be broken and water will slowly drip out and the level will drop obviously. The highest point of the fuel system is the injectors and or fuel filter, fuel runs away from the injectors and it won't start until fuel is pumped back up to them from cranking.
A common place to let air in is from the spill pipes, cheap and easy to replace, think I paid £4 for a MTR of it from my local indy, even if they look good in situ, as mine did, removing them showed cracks every where.

I get that, I didn’t understand the link to the engine not switching off, until I re-read and saw that it was cured with a new solenoid (and then added the edit to my reply).

swmeader · Mar 29, 2021

Flossie said:
What engine?
If TDI replace your leak off pipes.

Thanks Flossie

swmeader · Mar 29, 2021

tottot said:
Solenoid replaced and working he say's.

Air getting into the system, then engine has to turn enough for the pump to self bleed.
Likely places for air to get in and fuel to drain back to tank. Are as Flossie says leek off pipes for the injectors. Fuel filter seal or even a pin hole in the can for those who do not change often enough. Lift pump diaphragm/valves. Less likely are problems with the fuel pipes themselves but any joint can be suspect.

Thanks Tot tot

Slow starter

swmeader

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Turboman

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Flossie

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bluedog333

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tottot

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bluedog333

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swmeader

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Flossie

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bluedog333

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swmeader

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swmeader

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