Hi,
I have a very odd problem with the autotech upgrade kit:
Although all paramters in mapping are changed according to the data found here in the forums (and some more) the railpressure keeps spiking up to 170-180bar in rmp range above ~5800_min under WOT and part throttle.
Since a few weeks I've done nothing else than logging (With vehical logger) and testing different mapping changes, but no luck so far.
I logged a lot of HPFP PID parameters, and from the point where the railpressure exceeds the requested pressure, the delta angle of the MSV (Quantity regulator valve) drops to 0 and the "I" part of the PID controller freezes. So basically, with 0 duty cycle the for the MSV, the bypass inside the pump should be fully open to "bleed" the excessive fuel into the low pressure side.
So far, I would say this is a "correct" behavior, as the ECU tries to lower the exceeding railpressure, but for some reason the hardware does not respond accordingly.
Fo testing purposes, and to go sure the pump itself is not at fault, I bought a genuine new Hitachi HPFP, and installed it "as is" in stock form.
Immediately the railpressure is regulated correctly. Then I installed the autotech kit in the new pump, and the problems are back immediately.
A new RS4 pressure limiting valve is also part of the setup plus a upgrade intank fuel pump.
For some reason I cant wrap my head around how it is even possible to have (at max) 180bar railpressure with a 130bar pressure limiting valve except for one thing:
What if the 1.5mm restriction in the "T" piece which redirects the overflow from the PLV to the low pressure fuel supply is causing this issue?
But then, there would be heaps of others having this same problem as soon as the autotech kit is installed...?
Maybe someone has a bright idea for a solution, or even first hand experience with this situation?
BR
Alex
Alex
You have any picture of this 1.5mm restriciton in T piece?
To I can understand waht piece is this, and can hel you in a solution
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