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Fuel pressure solenoid Help Find??

so where can i find my fuel pressure solenoid at on my galant vr4 92 #145????
 

Terry Posten

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Dec 16, 2003
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Davenport, Iowa USA
Find the regulator on the driver side end of the fuel rail. Trace the vac line that is connected into that unit back to the solenoid that is on the firewall. If the vac line goes straight into a vac source, the solenoid has already been removed..

The solenoid should be on the firewall next to the brake master cylinder if I remember correctly. It has been 4 years since I took mine off.
 

does it matter if you have the fuel pressure solenoid will it mess up the car???
 

656of1000

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Jan 18, 2005
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292
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Phoenixville, PA
That solenoid cuts the vacuum source to the FPR. It's meant for warm engine starts to keep the idle smooth. In other words, if you take out the solenoid, then go to the store across town, when you start the car back up, it'll idle pretty crappy for a little bit. No big deal, really.

...At least thats how I understood its purpose /ubbthreads/images/graemlins/grin.gif
 

Yes, exactly, it helps with hot starts by removing vacuum from the FPR for 2-3 minutes, which raises the fuel pressure 7-9 psi. Most guys have removed it, but a few cars seem to really have an issue with hot starts without it.
 

jepherz

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Aug 8, 2004
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Quoting Terry Posten:
Find the regulator on the driver side end of the fuel rail. Trace the vac line that is connected into that unit back to the solenoid that is on the firewall. If the vac line goes straight into a vac source, the solenoid has already been removed..

The solenoid should be on the firewall next to the brake master cylinder if I remember correctly. It has been 4 years since I took mine off.



I believe that the correct solenoid is one of the two mounted to the air filter can. The other located on the can is the boost control solenoid. The one located on the firewall is for the EGR valve or the charcoal canister, I'm thinking... Someone please correct me if I'm wrong!
 

Yes, stock location is on the rear of the factory aircan. All the solenoids look basically the same: a black plastic cylinder, 2 or 3 vaccum ports on one end, and the 2-prong electrical connector on the other end. The FPR solenoid has 2 vaccum lines, and an oval vent filter on the NORMALLY CLOSED port.
Its VERY easy to tell if you have an FPR solenoid installed: just traces the vaccum line backwards from the FPR. Normally, the vaccum line goes from the FPR to one of the metal tubes behind the motor, and comes out on the passenger's side to another vaccum hose to one port on the FPR solenoid. Then, from the other port of the FPR solenoid the vaccum line goes to another metal tube behind the motor, and comes out to a vaccum line that goes directly to an intake manifold port.
If your FPR vaccum line instead goes directly from the FPR to the intake port, your FPR solenoid has been removed or bypassed.
 

JNR

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Apr 23, 2004
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9,814
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ca
Quoting keydiver:
Yes, exactly, it helps with hot starts by removing vacuum from the FPR for 2-3 minutes, which raises the fuel pressure 7-9 psi. Most guys have removed it, but a few cars seem to really have an issue with hot starts without it.



Interesting. I wonder if that's why mine will not want to start if I drive it for some time and then get gas...Takes a little bit, then it starts off fine. If that's the case, I wonder if I should rig up something someday as a bypass so to speak, in situations like that. It'd be rare, but what a PITA when it happens. However, if I know what it is caused from, then it won't bother me as much.

I just wonder then why it's "bad" to have the FPR solenoid hooked up, or why do people remove it then?

IIRC, you use this solenoid for the Cyclone activation on your chips (with that option), right Jeff?
 

jepherz

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Only reason I can think to remove it is to simplify things and clean up the engine bay. Possible another source for a leak too.
 

without one would it cause rough idle when it is hot? I have a aeromotive setup and i have a rough idle when it is fully warm. Im running 37psi fuel presure with the vacume off.
 

Terry Posten

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Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
I could not remember where the unit was on my GVR4. The 1G I was working on a few weeks ago has it on the fire wall next to the brake booster.
 

Quoting JNR:
IIRC, you use this solenoid for the Cyclone activation on your chips (with that option), right Jeff?



I use a FPR-style solenoid, but it doesn't necessarily have to be connected to the FPR solenoid harness. Many people use the purge or BCS solenoid harness. I can program the chip for any output of the ECU, but you *should* use an FPR solenoid itself to do the Cyclone plumbing, as it has all 3 ports and is configured properly.

An Aeromotive AFPR without the FPR solenoid will do the same thing. The car will idle rough and stumble for a little bit when you first do a hot start. Just think how hot all that fuel sitting in the fuel rail got while you were in the Kwikky Mart! /ubbthreads/images/graemlins/wink.gif
 

ktmrider

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Sep 10, 2007
Messages
3,128
Location
Tempe, AZ
Quoting Terry Posten:
I could not remember where the unit was on my GVR4. The 1G I was working on a few weeks ago has it on the fire wall next to the brake booster.

Yep, TEL's have it by the booster, GVR4's are on the air can.
Like mentioned many folks remove it when deleting the EGR rats nest, sometimes by accident but often for asthetics ( clean bay or wire tuck ).
Me personally, leave it on for DD.
 
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