5 replies to this topic

[panda]

just bought a fmu from ebay, no istructions on how to install!
any one installed one on and can give me tips?
it has three openings, one on top and two on the bottom... what go's where?

[CRXdan]

one is for vacuum, one if for fuel return inlet, one is for fuel return outlet.

What fmu did you get?

[panda]

i got a blox fmu 12.1 ratio!

[therealtime]

it goes like this:

smallest one on top goes to vacuum source on intake (after throttle body)
tip: just tee into the vacuum line for the stock fuel pressure regulator

highest bottom fitting goes to the fuel return line from the stock fuel pressure regulator

very bottom fitting goes to the return line to the tank that comes through the fire wall

happy boosting,
-tony

[CRXdan]

apparentley nothign shoudl be teed off rom the FPR. it takes time for those vacuum lines to pressurize/see vacuum and the fpr needs a responsive source, teeing off it will increase the response time and cause lower fuel pressures when applying the gas and higher fuel pressure when releasing the gas.

Edited by CRXdan, 31 March 2005 - 01:31 AM.

[therealtime]

as small as the diameter of that tubing is, it will not make a difference (1/1000th of a second to pressurize/depressurize will not cause any problems). just don't use really long lengths if you can help it. less than a foot from the fpr to the fmu will not cause a noticable (or probably even measurable) difference.

the instructions that came with mine said to tee there.

besides, the supply from the tee is going to a device that will be over-riding the stock fpr anyway

-tony

Edited by therealtime, 31 March 2005 - 03:10 PM.