Bosch pump cold start solenoid.

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Geoffrey Gould
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Posts: 546
Joined: Sat Jun 25, 2005 7:26 pm
Location: Bristol.UK.

Bosch pump cold start solenoid.

Post by Geoffrey Gould »

Hello all. On the 1.9 TD Bosch injection pump there is a electrically operated valve, as opposed to the waxstat operated long lever type, this is on the side of the pump facing the radiator, It appears to alter the pump timing and I think it retards the timing when it is connected to 12Volts. It drops the engine revs and the engine sounds 'softer'.when connected.
The question is when it is connected what does it do? I reckon it should be connected when the engine is hot but I could have it a++e about face.
Any ideas please?
Cheers.
Geoff.
PS. The waxstat is US. The moulded all shapes water pipes are no longer available and the pump is badly worn etc. hence the change of pump.
1991 BX 1-7 td Auto.


I MAY NOT BE ALWAYS RIGHT BUT I AM
NEVER WRONG.
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DavidRutherford
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Post by DavidRutherford »

You're quite correct. When de-energised, the injection timing is advanced. That's for cold starting. When the engine warms up, one of the various thermal switches on the thermostat housing closes and energises the solenoid, retarding the injection back to "normal hot-running"

Certainly that's how it works on my 405 1.9TD anyway.
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Geoffrey Gould
BXpert
Posts: 546
Joined: Sat Jun 25, 2005 7:26 pm
Location: Bristol.UK.

Pump timing.

Post by Geoffrey Gould »

Hello David, thank you very much for the reply, I am not quite as daft as I thought I was. Now I can sort it.
Cheers.
Geoff.
1991 BX 1-7 td Auto.


I MAY NOT BE ALWAYS RIGHT BUT I AM
NEVER WRONG.
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