i scarped the original ecu from my donor (nissan 1.8 turbo injection) as it was way to complex and i have a ms off paul, before i changed it over i'm sure my fuel pump used to run up to pressure then either slow down or cut out now id dosnt it just runs all the time...... is this correct ?

i know it needs to pump all the time but i feel sure it used to run then go quiet.

[Edited on 14/5/06 by graememk]

It will pump when the cars running but should only run when the engine off to prime the fuel system then stop..

Have u got a leak in the fuel system somewhere or a dodgey relief valve on the fuel rail??

so what tells the pump to stop pumping? is there a pressure switch in the submerged pump ?

It should run for about 2 seconds after turning on the ignition and then stop until the engine is turned by the starter motor.This is controlled by the megasquirt settings.
Paul.

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Originally posted by graememk
so what tells the pump to stop pumping? is there a pressure switch in the submerged pump ?

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The pump must stop if the engine stops or you will be in trouble if you have a smack and the fuel line is damaged...lots of fuel being pumped out with nowhere to go.