Firewall mounted solenoid

Hi all,

Just putting the engine in the wagon and have been looking at stock gsr engine bays and have spotted a firewall mounted
solenoid that looks to go from the intake to the solenoid then back to the fuel pressure reg....Is it imperative that i have it and secondly can someone clarify its purpose?

Cheers,
Ted.

it's to cotrol the fuel pressure at certain points as far as i'm aware it's not 100%necessary a few people have deleted it i personally am running it. i beleive it's for fuel cut in an overboost situation

Get rid of it, its just xtra weight

Hahahaha as long as i dont actually need it as such i will keep it disconnected as i dont actually have one :S but i do have the factory boost solenoid

Careful here guys. Have a think about it before you go ripping bits off.
It supplies manifold pressure to the fpr, and is ecu switched. What are the choices, either pressure or vacuum.
There is no use switching vacuum to the fpr as it will just drop rail pressure. But if you have +map then you have a rising rate fpr.
It will not have anything to do with boost cut (how can it drop the rail pressure when there is only +map in the manifold?)

So I think it turns off at -map and is a single rate fpr, then switches on at +map and becomes a rising rate fpr.
Without it you will not get any increase in fuel pressure and the more boost the leaner you get. Will run good till it blows up...
Leave it on unless you can retune your injectors.
My2c

Ive been wrong before tho

I havnt been runnin 1 for 6 years on a standard ecu

U can keep it if u want

Its got to do with emissions

MD113721 VALVE ASSY,EMISSION SOLENOID

Are you talking about these things Ted....?



I was contemplating deleting them too. Purely because of the new throttle body only running a single vacuum line. I'll also be running a haltech so I can probably get away with not having these.

vin18m those you can delete one is for the egr the other I'm not 100% on but i don't have it.

jack it can drop rail pressure to the manifold by venting the pressure in that line to atmo it has 3 ports one of which is capped

So do i need it or not hahaha i dont mind if i need it i will find one and use it i just need to know if its going to destroy the engine if i dont use it

it's safe to run without

jack of all said:

Careful here guys. Have a think about it before you go ripping bits off.
It supplies manifold pressure to the fpr, and is ecu switched. What are the choices, either pressure or vacuum.
There is no use switching vacuum to the fpr as it will just drop rail pressure. But if you have +map then you have a rising rate fpr.
It will not have anything to do with boost cut (how can it drop the rail pressure when there is only +map in the manifold?)

So I think it turns off at -map and is a single rate fpr, then switches on at +map and becomes a rising rate fpr.
Without it you will not get any increase in fuel pressure and the more boost the leaner you get. Will run good till it blows up...
Leave it on unless you can retune your injectors.
My2c

Ive been wrong before tho

Click to expand...

On this one jack..you are wrong...Ive removed mine years ago and used the manifold pressure to tell the reg whats going on.Thats with standard reg and now an Aeromotive one.

Thats my stubby then...
Cheers guys

How the Pressure Regulator Control (Fuel Pressure Regulator) Solenoid Works

The purpose of the PRC solenoid is to prevent vapor lock of the fuel during hot restart idle. Vacuum to the pressure regulator is momentarily cut and the fuel pressure increased to slightly more than 41.2 PSI.The Fuel Pressure Regulator solenoid is called the PRC solenoid for Mitsubishi vehicles. The abbreviation for FPR is taken by the Fuel Pump Relay so PRC is used to denote the Fuel Pressure Regulator solenoid otherwise known as the Pressure Regulator Control solenoid..Conditions of OperationFuel pressure is raised when any of these conditions are met+) Cranking(+) After restart. If it's been less than 10 seconds since the engine was turned off, the coolant temperature is above 194F, intake air temperature is above 95F.(+) After restart. If it's been less than 2 minutes since the engine was turned off, the coolant temperature is above 194F, intake air temperature is above 95F and throttle is less than 1000 RPM.


Thanks guys. Ive gone and got edumakated about the solonoid.

Pull it ted..