04-02-2014, 12:20 PM
(02-02-2014, 11:09 PM)Martin306 Wrote: The semi ECU pump will have a built in immobiliser (yes it's in the pump not the ECU) and an electronic RETARD. it's not an advanceuses PCM to control. Full constant 12v is fully retarded, and the "off" pulses get larger to advance. So from that I'd guess it's a solenoid on a spring rather than a servo.
From what I can make out, it only exists to keep the engine quiet and more refined, because it still has the mechanical advance.
to bypass the immobiliser, simply take off the armour, rip out the circuit board and wire the stop solenoid directly. Then it'll work the same as the full "proper" mechanical pumps. So it's not totally useless if you don't want it to be.
Assuming it works the same way as my semi electric Bosch.
It is an advance controller, it just so happens that you apply voltage to back off the timing because of the way the pump works, the regulator is just set to maximum pressure and then there's a solenoid valve that is actuated by the ECU that regulates the pressure to the timing piston. It's just that there's multiple inputs into the ECU to regulate what turns on when, so EGR is disabled until the engine heats up, the timing is adjusted dynamically based on temperature at different engine speeds etc.
They also have the wire on the 3rd injector for feedback about needle lift time - that's how it automatically compensates for the "base" timing position on the pump bracket - it knows the crank angle and when the injector fires, so can then precisely control the start of injection (advance..) even if the pump isn't precisely set - up to a point.
And I think you mean PWM - Pulse Width Modulation - PCM is what digital audio in CDs use
Really want to get one apart and read the chips, I bet you could tune them really well - it'd get rid of all the problems that XUDs have when you piss with bigger heads and levers with the advance not coming in at the right time.