Fuel Pressure Solinoid?

[daren_p]

I installed my aeromotive fpr and hooked the vacuum line up the same way as stock, from the intake mani to the fuel pressure solinoid & then to my fpr. Is this the proper way or should I be taking it directly from the intake mani? What exactly does the factory fps do?

 

[FORMONTOYA]

from my understanding...it raises fuel pressure slightly for hot starts so the gas does not vaporize. some people hook it up, some don't. i live in Texas and see several months above 100f, so mine is hooked up.

jim

 

[L2RTSiAWD]

It will be fine hooked up that way.

 

[steve]

The FPS is set up to connect the FPR manifold reference to either the intake or Atmosphere.
When it's connected to the intake the fuel pressure will track base pressure + manifold pressure, otherwise its fixed at the base pressure for the hot start issue that FORMONTOYA mentioned.

Unless you have a bad FPS I'd leave it hooked up.

Steve

 

[daren_p]

So its for a "hot" start, why would you need this? Someone else told me it was for a "cold" start. Under the "cold" start condition you wouldn't get vacuum (I guess solenoid would be connected to atmosphere instead of intake), to give you a rise is fuel pressure for fuel enrichment, I guess until the cars warms up abit?

EDIT: I guess I should say, it works for both hot & cold starts then?

 

[steve]

2G's may be different but here's what the factory had to say about it in the 1G tech manual.

"Usually, the negative pressure (vacuum) of the intake manifold is applied to the fuel pressure regulator, and, because the fuel pressure is thus held at a fixed constant level relative to the pressure within the intake manifold, the amount to fuel injected is regulated so as to be proportional to the injectors’ actuation time. If, however, the engine coolant-temperature and the intake air temperature are high when then engine is started, the engine control unit sends a flow of current to the fuel pressure control valve, with the result that outside air (atmospheric) pressure acts upon the fuel pressure regulator. As a result. the fuel pressure is increased and the generation of fuel vapors caused by high temperature is suppressed, thereby maintaining idling stability immediately after restarting under high temperature conditions. Note that there is a return to the usual fuel pressure level after two minutes or more have passed after starting is completed."

Steve

 

[CarTunr22]

Will the ecu throw any codes if you un plug the solenoid from the Wiring harnes? im 90% sure i want to keep it but i was just curious.

 

[staticbrainwash]

Only if your a CA 1g, or any 2g. I think for 1g's though all 94's started throwing codes like 2g's. I could be wrong though.

There is though, a way to wire in a resistor to simulate the fps is still there. So there won't be a code thrown if you are throwing.

 

[CarTunr22]

Thanks for the info, i guess the worst that would hapen is i throw a code and i plig it in or figure out how to make the ecu "think" it's there.

 

[staticbrainwash]

Exactly. I mean, if you really want it just gone period try unplugging it. If you don't mind if it sits there, just run a line from the manifold to the fpr.

Personally, i kept mine, because it's only 2 lines, and we get really effed up weather here in michigan.