Where to install fuel pressure gage (permanently)

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KINGJOHN808
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Joined: Sat Feb 16, 2019 2:27 am
Location: Ewa Kai

Where to install fuel pressure gage (permanently)

Post by KINGJOHN808 »

Aloha!

Have searched but unable to find “where to” install fuel pressure gage on a 1984 633csi. Is it best at the FPR or at the fuel rail? I want to install one permanently (under hood) as I do not want to install and remove.

Any pictures or a link to a Permanently installed fuel pressure gage would be greatly appreciated.

Mahalo’z.
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”
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RossDinan6
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Re: Where to install fuel pressure gage (permanently)

Post by RossDinan6 »

Here's my bling. Ireland Engineering adjustable FPR. It has a 1/8 port for a gauge and came with a china chrome gauge. I had the VDO and refinished it before install.
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Ross
'84 633 Dinan turbo
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RossDinan6
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Re: Where to install fuel pressure gage (permanently)

Post by RossDinan6 »

I guess I didn't answer the question you asked. At the FPR or the fuel rail are the same thing. The FPR is at the end of the fuel rail and acts as a restriction between it and the tank to set the pressure. I suspect any aftermarket adjustable regulator will have a gauge port.
Ross
'84 633 Dinan turbo
KINGJOHN808
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Re: Where to install fuel pressure gage (permanently)

Post by KINGJOHN808 »

RossDinan6 wrote: Sun Mar 13, 2022 2:42 am I guess I didn't answer the question you asked. At the FPR or the fuel rail are the same thing. The FPR is at the end of the fuel rail and acts as a restriction between it and the tank to set the pressure. I suspect any aftermarket adjustable regulator will have a gauge port.
Cool! So the adjustable unit is where your original FPR was installed. It’s just set and forget or is that something that you have to continue to monitor? Going to look at the Ireland Engineering unit. Mahalo’z again.
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”
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RossDinan6
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Re: Where to install fuel pressure gage (permanently)

Post by RossDinan6 »

It is set and forget. While not really necessary on a stock engine It does doll things up. Being modified, and running a standalone ECU mine does benefit.
Ross
'84 633 Dinan turbo
KINGJOHN808
Posts: 127
Joined: Sat Feb 16, 2019 2:27 am
Location: Ewa Kai

Re: Where to install fuel pressure gage (permanently)

Post by KINGJOHN808 »

RossDinan6 wrote: Sun Mar 13, 2022 1:49 pm It is set and forget. While not really necessary on a stock engine It does doll things up. Being modified, and running a standalone ECU mine does benefit.
Mahalo’z.

Kinda what I’m after is fit and function. I like the fact of knowing at any given time what the pressure is, and the added bonus is looks when I pop the hood while in the front yard drinking a beer and wiping down the car on Sundays. 🤣🤣
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”
TimU
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BMW E24 M30 Fuel Pressure Schrader Valve Test Port

Post by TimU »

Just sharing my approach here:

Installed:
Image

I bought an Actron CP7838 Professional Fuel Pressure Tester (made by Bosch) from Amazon.com.au for AU$55.
https://www.amazon.com.au/gp/product/B0009XQUKC

Image

Components:

Short fuel hose:
Image

T-Piece with 1/2 inch Schrader Valve
Image
Image

Test results (Engine running at idle):
Image
04/1986 635csi Euro spec
Australian Delivered, RHD
KINGJOHN808
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Re: BMW E24 M30 Fuel Pressure Schrader Valve Test Port

Post by KINGJOHN808 »

Have since removed gage and pending placement in the correct spot.
Last edited by KINGJOHN808 on Thu May 05, 2022 3:10 pm, edited 1 time in total.
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”
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86_6series
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Re: Where to install fuel pressure gage (permanently)

Post by 86_6series »

The photos are confusing. The first set of photos shows the gauge at the entrance to the fuel rail.
The last cropped photo looks like the gauge is after the FPR. The gauge won't work if it's after the FPR.
In that position, after the FPR, the fuel is being sent back to the fuel tank. Little or no pressure will
be detected there.
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
KINGJOHN808
Posts: 127
Joined: Sat Feb 16, 2019 2:27 am
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Re: Where to install fuel pressure gage (permanently)

Post by KINGJOHN808 »

86_6series wrote: Thu May 05, 2022 11:01 am The photos are confusing. The first set of photos shows the gauge at the entrance to the fuel rail.
The last cropped photo looks like the gauge is after the FPR. The gauge won't work if it's after the FPR.
In that position, after the FPR, the fuel is being sent back to the fuel tank. Little or no pressure will
be detected there.
Yep, your right about the pics (my reference photo) and the position. After looking at it again I realized that the picture I used for reference is backwards. Going to move the gage (smaller gage pic) to the fuel rail side.
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”
TimU
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Re: Where to install fuel pressure gage (permanently)

Post by TimU »

86_6series wrote: Thu May 05, 2022 11:01 am The photos are confusing. The first set of photos shows the gauge at the entrance to the fuel rail.
The last cropped photo looks like the gauge is after the FPR. The gauge won't work if it's after the FPR.
In that position, after the FPR, the fuel is being sent back to the fuel tank. Little or no pressure will
be detected there.
Are you talking about my photos or John's?
All of my photos show the test port at the head of the rail.
Which photo do you think looks funky?
04/1986 635csi Euro spec
Australian Delivered, RHD
KINGJOHN808
Posts: 127
Joined: Sat Feb 16, 2019 2:27 am
Location: Ewa Kai

Re: Where to install fuel pressure gage (permanently)

Post by KINGJOHN808 »

TimU wrote: Fri May 06, 2022 1:18 pm
86_6series wrote: Thu May 05, 2022 11:01 am The photos are confusing. The first set of photos shows the gauge at the entrance to the fuel rail.
The last cropped photo looks like the gauge is after the FPR. The gauge won't work if it's after the FPR.
In that position, after the FPR, the fuel is being sent back to the fuel tank. Little or no pressure will
be detected there.
Are you talking about my photos or John's?
All of my photos show the test port at the head of the rail.
Which photo do you think looks funky?
Aloha Tim. Yep, I deleted my post after I discovered that I had installed the fuel pressure gage in the wrong location. Since I had already cut my fuel lines, I just decided to replace both the incoming and the return lines from the fuel rail and then FPR.

Waiting on my new gage as the one I got was leaking the oil they use to stabilize the needle. Will post pics of the install and location once I get it.

Mahalo’z.
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”
KINGJOHN808
Posts: 127
Joined: Sat Feb 16, 2019 2:27 am
Location: Ewa Kai

Re: Where to install fuel pressure gage (permanently)///INSTALLED///

Post by KINGJOHN808 »

Can’t believe my entire post got removed. Too much to type all over again. Bottom line, becarefulmwhen trying to buy “FUEL INJECTION HOSE” from Napa, Autozone, Oriellys. Had a hell of a time trying to get all three to find “Fuel Injection Hose” versus “Fuel Hose”.

Funny thing, Autozone and Orielly employees kept trying to stress that it’s the same thing until I showed them on the website AND on the actual hose that it stated “NOT INTENDED FOR FUEL INJECTION USE”. 🤣🤣

Either way, got the 8mm hose and installed all new fuel lines to the fuel injection rail and from then FPR back to the tank. fuel pressure gauge. When idling, she reads 37ish to 40ish. The fuel line/gauge is attached via coupler to the transmission dip stick tube so as not to cause any undue vibration.
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Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”
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