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Discussion Starter #1
I'm wondering... All I can get from the service manual is that it tells when to switch from manifold pressure to barometric pressure. That's it. Shouldn't the Fuel Pressure Regulator always be on the manifold pressure anyway since that is where the reading should be taken for proper fuel measurement to be sent into the combustion chamber? I am thinking of going straight from the manifold pressure line on the back of the plenum straight to the FPR.
 

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Aghhhh
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Don't quote me on this, but I think it has more to do with emissions control than anything else. The NA doesn't have one at all, and I've never seen a car with an aftermarket FPR that kept the solenoid.

Try the Stealth Tech Manual on Jeff Lucius' site. I think that explains the function of the FPR solenoid.
 

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Turbo-Less
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Dozens of us have removed it with no problems at all. I honestly don't know what it does, but I know that nobody that I know of has had problems by taking it out. I will say that I also took the EGR system out at the same time so it's slightly possible that effects it.

Do a search on "spider web" removal or similar and you'll see how it's done. If I remember correctly, I went from the bigger nipple on the front side of the plenum, near the TB, then into a "T", one to the FPR and the other to the BOV.
 

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Resident mad scientist
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it's to raise the fuel pressure at idle and part throttle (I think), when restarting the car on hot days with high underhood heat. The extra pressure is supposed to prevent vapor lock....

I don't think anyone has reported any issues from removing it.

B
 

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Discussion Starter #5
Yeah, reading through Stealth316, found my answer. So it's coming out this week when I remove a bunch of other crap I don't need. It might explain why I am running so damn rich. I'm getting like 200 miles per tank of gas now. I think the FPS might be sending the wrong signal to the FPR keeping more fuel flowing than is normal.
 

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I am in the process of removing it along with a bunch of other crap.


NOTE: When doing EGR plates, do not drop ANYTHING in between the turbo and the heat shield. Trust me. :rolleyes:
 

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Bored User
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I removed mine several months ago with no issue. I've removed it and all the other emissions equipment on several carswith no issue.
 

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Senior Fanatic
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From my FPR upgrade web page:

"The fuel pressure control solenoid (or valve) is used by the engine control unit (ECU) only to increase fuel pressure during hot engine starts when there is a greater possibility of fuel vapor being generated in the fuel lines. When the air intake temperature exceeds 140ºF (60ºC) and the engine coolant temperature exceeds 194ºF (90ºC), the ECU uses the fuel pressure control solenoid (for up to two minutes) to allow outside air into the vacuum hoses to increase fuel pressure. In addition, the ECU increases fuel injector activation duration (richens the mixture). These two actions by the ECU are what I believe is a cause of the hot-engine hard-start condition I and many others have experienced on a hot summer day after turning the engine off for a short while. The engine acts like it is flooded for maybe a minute then runs fine. Because this is the only purpose of the fuel pressure control solenoid, I decided to remove it. I don't think there is much we can do about this part of the ECU programming short of going to stand-alone engine management. Owners that have removed the fuel pressure control solenoid, whether upgrading to an aftermarket FPR or not, have not reported problems related to this."

I removed the FP solenoid last spring before going to the NG in St. Louis. It was between 90 and 100ºF most the time at the NG and after short or long stops with a hot engine I never once had a hot-start problem. Ditto for this summer in Colorado. In fact, I would say this is the cure (or a good part of it) for hot-start problems that many of us have encountered in the summer months. What was Mitsu thinking?
 

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More Than Meets the Eye
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The DSMs have it too. I wonder if it's something that cropped up on the Starion and they just incorporated it into the rest of their turbo models?
 

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One Shizz-rippin' M F
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I have it removed, and know of a good 6-7 others with it removed, and none have had any problems. I strongly suspect it will not solve your rich condition. The solenoid is not normally in use. Also note that it is not capable of increasing fuel pressure at neutral, or positive manifold pressure, only at idle/light throttle. If it opened under boost it would decrease the fuel pressure.
 

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I drive, therefore I am.
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i removed mine, car ran exactly the same way, and had the same problem starting up.... but my walbro was wining SOOOOO damn loud that it sounded like a jet powering up when I started the car. (i can't hear it when im driving, but at idle, its DAMN loud) so i put it back in:bandit:
 

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One Shizz-rippin' M F
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wizard said:
i removed mine, car ran exactly the same way, and had the same problem starting up.... but my walbro was wining SOOOOO damn loud that it sounded like a jet powering up when I started the car. (i can't hear it when im driving, but at idle, its DAMN loud) so i put it back in:bandit:
I bet your talking about the fuel pump resistor bypass, not the FPRS. If removing the fuel pressure regulator solenoid made your fuel pump loud you have a problem;)
 

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I drive, therefore I am.
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*GT said:


I bet your talking about the fuel pump resistor bypass, not the FPRS. If removing the fuel pressure regulator solenoid made your fuel pump loud you have a problem;)
umm... i AM talking about fuel pump resistor actually...... wheres the FPRS???

oops
 

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The FPRS is on the firewall with all of the other solenoids. Follow the blue striped vacuum hose and you will find it. I believe it is the left most solenoid as you are looking at the firewall.
 

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Ninja Performance
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removed long time ago, never any issues
 

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I drive, therefore I am.
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any more info on what it does? any links?
i'm guessing to remove it, just cap off the hoses right? or do they need to cnnect to eachother..?
 
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