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Injector Pressure for 2.5NA Diesel?

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Does anyone know the correct injector nozzle opening pressure for the 2.5L naturally aspirated diesel engine?

I have a 1989 One Ten and recently had the Lucas CAV injectors cleaned and replaced the nozzles. The injectors were previously set around 150Ats (2200psi), but the workshop manual I have specifies 135Ats (2000psi). When I had the nozzles set down to 135Ats the timing was messed up due to the lower pressure. The manual I have covers the 2.25 and 2.5NA diesels and does not list different pressures for each. The nozzles are the same but I don't know if the pressure should be different for the 2.5NA.

The vehicle previously ran very well after an injection pump rebuild with the old nozzles set at 150Ats.

I live in Central America and the injector shops here do not have information on correct pressures.


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book value is 135bar, however 150bar cracking pressure does make an improvement in a 2.5NA and dosnt cause any problems for the Lucas/CAV pump

Thanks for the reply.

I had the injection pump rebuilt recently due to valves leaking internally. Since then the vehicle has run well and the timing was correct. I then replaced the fuel lift pump. At the same time I had the nozzles checked and on 3 of them the side hole was totally blocked and could not be cleaned. I replaced the nozzles with ones from some rebuilt injectors and now the timing seems to be advanced too far. There is not enough movement in the pump to correct it with out opening the cover and moving the pulley a notch.

The only thing that I did that would have affected the timing was lowering the opening pressure of the nozzles. So I didn't know whether to move the pulley a notch or raise the opening pressure back to where it was. I will probably raise the pressure back up and then see what the timing is like.

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why do you say the timing is out? have you got 'diesel knock'?

surely if the IP has been rebuilt then the timing indent (where you shove the timing pin on the side of the IP body) should be in the correct position on the pump shaft? and should enable you to line up the flywheel timing pin slot? I cant see how 15bar increase is equal to 1 tooth on the timing belt?

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