Hello guys, Can I bypass the stock fuel solenoid conecting stock FPR diretly to intake manifold?? I?m having fuel issues and I dont now if bypassing it I will go more out of fuel than controlling the solenoid the fuel press.

Thanks so much in advance

 

Yes, just be sure to disable the periphery bit for it in the ECU to avoid a CEL.

 

fpr solenoid doesn't affect fuel just controls cold start up. I'd look at injectors and fuel pumps

 

FPR solenoid adds fuel on hot start-ups. If you leave the connector on but bypass the vacuum hoses you should be ok.

 

Thanks so much guys, I will leave the connector on and I bypass the vacuum line to check if the problem is the solenoid

 

Hello guys,well my problems with the fuel gone.The problem was the fuel pressure solenoid.I had a problem that going over 19psi the car was out of fuel,once was bypassed the solenoid,the problem gone and car runs ok like in past boosting perfectly at 22psi.My evo9 is a EURO-SPECS , Evorider and 4kinboost told me that FPS dont affect the fuel pressure controls,in my case it was affected alot,so we have to check if there are some differences in the ECU controls between US and EURO specs evos.
Thanks so much for your help

 

^ I hope you don't think I meant fuel pressure regulator, I was referring to the fuel pressure solenoid



In the picture above it shows both the solenoid and regulator, once you disable the solenoid it can actually be removed from the car, in the US.



Here's my car with it removed, and just the FPR in place.

 

I doubt the Euro controls would be different because the fuel solenoid is not part of emission equipment.

Without looking it up in the manual I don't know what pressure the fuel pressure regulator on an Evo maintains. So, lets say, for the sake of this discussion, it maintains 40 psi. Now this is 40 psi above whatever the manifold pressure is. So if manifold pressure is 10 psi vacuum then fuel pressure is actually 30 psi.

What the solenoid does is vent the fuel pressure regulator to atmosphere and the regulator now does not see manifold pressure. So, with the 10 psi manifold vacuum you still get 40 psi from the fuel pressure regulator. The solenoid is triggered during hot start and is intended to clear out fuel vapor that may have accumulated in the line.

What I can't figure out is how this would cause fuel starvation unless the solenoid was always venting to the atmosphere. Then fuel pressure would not go up during boost.

 

Yah, maybe its venting all the time to atmosphere,for thatreason the pressure dont go up under boost.Checked fuel pressure now,and is ok.
The most important is that the problem gone,and the car runs perfect.

 

No sir, Im talking and thinking about fuel pressure solenoid like you

 

Thanks this was helpful. I was just looking at doing this

 

All the way,just bought a Walbro 255 fuel pump,Agency power fuel rail and a Aeromotive FPR with braided lines to run safe forever with good fuel feeding.

 

I removed my FPR solenoid with no ill-effects even during the winter. I have a Walbro 255HP and I disabled the emission bits with ECUFlash.

 

How Can I remove the ecu bits for remove completely the solenoid from the engine ?? I,m looking to remove the EGR too and I need to disable too

Thanks in advance

 

^ https://www.evolutionm.net/forums/ec...solenoids.html