2G Fuel Pressure Solenoid Help P1105

[mistagst]

ok so i just got a CEL and i checked it and it says its my Fuel Pressure Solenoid i have heard you can clean these to fix the problem. my question is where is it located and what exactly do i have to clean or change.
Thanks

 

[tvscream]

so i just checked the ohms on the FPS that I bought from someone on these boards and it reads 1.

I also checked the ohms on my old FPS and it reads 54.

Repair manual says normal conditions, the ohms on the FPS should be 36-44.

F-M-L!!!

 

[Majikterror]

Does either one of them work?

 

[v8s_are_slow]

So you can just bypass the solenoid? I have this code too. Not sure what the drivability issues are suppose to be. I don't have to worry about emissions. Wondering if I can just get rid of it if it's bad or if I have to have it. I don't know much about this solenoid and what it's there for.

 

[tvscream]

This solenoid doesnt seem to raelly do anything. I drove around with the cel on for months. I finally replaced it with a brand new part and no more CEL.

For those that are interested, the part number is:

MR126455 - VALVE ASSY,EMISSI

I ordered from JNZ, and it came out to 44 shipped.

 

[v8s_are_slow]

Well I'm sure it's there for something. If it actually has a purpose other than for emissions or just to annoy the hell out of you with a cel if it goes bad, I dunno. Just don't care to fork out money on a new solenoid if I don't need it.

 

[steve]

The FPS raises the fuel pressure on hot starts to avoid vapor lock. It's a two position switch. In the normal position it connects the fuel pressure regulator to the intake manifold so that it sees vacuum or boost. When activated it connects the fuel pressure regulator to atmospheric pressure via that "knob" which is actually a filter on the port. Since the regulator doesn't see the intake manifold vacuum the fule pressure remains at the base pressure and not the ~9 psi less it would normally see while cranking.

The ECU can tell that it's connected by watching for the inductive voltage kick a coil makes when you turn off the current.

 

[Boost92gsx]

cars vaccuming at 5 when it should vacum at 20 and as soon as i hit 1 pound of boost the car fully stutters almost like a rev limit.. The car has been like this sence my alternator ampage regulator blew up my battery and all of my light bulbs to the car and multiple fuses..

(my fpr selenoid spit a little fuel out of it at one point after all of the problems accuring)
please any ideas

 

[ramsack]

The ECU can tell that it's connected by watching for the inductive voltage kick a coil makes when you turn off the current.

which means you can't just put a resistor on there to try to trick the ecu!

 

[warranty]

Like Steve said, the FPR solenoid's only purpose in life is to cut off the vacuum signal (from your intake manifold) to the FPR on hot starts in order to raise fuel pressure and avoid vapor lock (again...on hot starts only).

Under all other conditions the FPR solenoid is open, letting the full intake manifold pressure "signal" to the FPR.

I bypass the FPR solenoid over 150K miles ago (I connected the intake manifold nipple directly to the FPR) and I've NEVER had a hot start problem. I also believe this is a more reliable system because now there is less point of potential failure. You do NOT want a cracked/leaky hose on the FPR lines because you want the FPR to receive the full intake manifold boost when you're boosting.

The FPR solenoid is technically not a smog device because it's always off during normal operation, though I suppose somebody could argue that by reducing the number of cranks on hot starts it's letting out less HC pollutants.

My advice: get rid of it. Less clutter in the engine bay and less point of potential failure in the engine system.

On my 95 GST I just unplugged the FPR solenoid and the ECU never ever threw a code. Weird.

 

[ramsack]

that is weird, but '95 may not operate the same as it is still considered a "visual" emissions in most places so maybe the ecu is programmed not to throw a code for it?