Nissan ECU Tuning

Mr Fast · Joined: 16 Nov 2003 Posts: 98

Is there anybody that knows how this system works??
does the controller\ecu add volt to the pump just by rpm or rpm and load??
what signal does the ecu gives the fuelpump controller +++

i may be way off here so any help would be great.

i cant find a good description of this system in the manual.

Otto

nzniggles · Joined: 26 Aug 2006 Posts: 56 Location: New Zealand

At the bottom of this page

http://300zx-twinturbo.com/cgi-bin/manual.cgi?list=efec&dir=&config=&refresh=&direction=forward&scale=0&cycle=off&slide=26&design=default&total=190

Mr Fast · Joined: 16 Nov 2003 Posts: 98

hmm still it doesnt tell me how the system works.

the problem i have, is that with 555cc injectors and dobble inlet on the fuelrails, the car runs out of fuel if the engine is at low rpm and i put the pedal to the floor, then it need a few seconds to run normaly again.
it looks to me that the fuelpump dont deliver inough fuel.
at full throttle there is no problem, so my guess is that the fuelcontroller speeds the fuelpump up to late.

if i could find out how the signals\system work's i may be able to modify the controller to run with higher volt at idle

kickerzx · Joined: 30 Aug 2004 Posts: 28 Location: Norway

how do you know it runs out of fuel? got a fuel preassure guage hooked up to it?

Mr Fast · Joined: 16 Nov 2003 Posts: 98

heisann

no i have not testet with a pressure gauge yet,
the engine lose power on one or several cylinders during hard accelration (if i starts from a low rpm), this dont happen everytime but inough to be enoying.
after a few seconds the engine regain fuel and run normaly.

Otto

nzniggles · Joined: 26 Aug 2006 Posts: 56 Location: New Zealand

nzniggles · Joined: 26 Aug 2006 Posts: 56 Location: New Zealand

I don't think it would be your pump as when they give trouble it's usually at higher RPM. You could bypass the controller temporarily to double check

Mr Fast · Joined: 16 Nov 2003 Posts: 98

Performance_Addict · Joined: 29 Nov 2007 Posts: 10

The TT has a 3 speed fuel pump controller that runs low voltage medium and high. It helps to give your OEM pump longevity and better fuel economy. If you are running an aftermarker pump like Walbro or Denso, wire a relay to it and it can run a full 12 volts all day long while the car is running. You can bypass the controller all together.

If your car is not getting fuel on the top end, you either have one of a few problems. Check your timing. Check your fuel pressure, then check your A/F reading with a wideband/datalogger or tailpipe sniffer. Once you have all of that data, you can find your problem.

Lastly, make sure you have a healthy MAF.