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1Back to top Go down    Fuel Pressure Regulator Test on Sun Sep 12, 2010 8:52 am

8675k


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Since I put this under the wrong headng the first time I am looking for a way to test the FPR and is there a source to purchase at a reasonable price?

    

2Back to top Go down    Re: Fuel Pressure Regulator Test on Sun Sep 12, 2010 5:17 pm

Crazy Frog

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Click here to access the FI troubleshooting page
At the bottom of the page there are 2 pictures showing you where to install a pressure gauge to test the pump and the fuel pressure regulator.

Bert


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1986 k75, 1985 K100rt, 1985 K100rt/EML sidecar.
    

3Back to top Go down    Re: Fuel Pressure Regulator Test on Sun Sep 12, 2010 6:23 pm

8675k


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I performed this test at the onset of my problem which was overfueling of the the engine. My test indicated a delivery psi of 36. After testing and od replacing the electrical components in the system I am leaning toward the FPR. I realized a change in engine performance when I shook the regulator.
I alson cannot hold a vacuum on the reg when pulling a vacuum with a pump as ir there is a hole in the diaphragm? I can also restrict the feed side fuel line and the engine runs fine.

    

4Back to top Go down    Re: Fuel Pressure Regulator Test on Sun Sep 12, 2010 7:01 pm

Crazy Frog

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The FI computer assumes that you get a 36psi pressure at the injectors .
In order to regulate the amount of fuel injected into the cylinders, The FI computer regulates the time (in milli secondes) that the injectors stay open.
The position of the vane on the MAF is what tells the FI computer how much load is on the engine and how much fuel has to be injected to balance the mixture air/fuel.
If your engine is 'overfueled' and you have 36psi fuel pressure, check the air filter and the MAF.

Bert


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1986 k75, 1985 K100rt, 1985 K100rt/EML sidecar.
    

5Back to top Go down    Re: Fuel Pressure Regulator Test on Sun Sep 12, 2010 7:45 pm

phil_mars


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Just a question out of left field. What happens if the TPS is in the permanent "WFO" position from the point of view of fuel mixture.


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Phil
    

6Back to top Go down    Re: Fuel Pressure Regulator Test on Sun Sep 12, 2010 7:47 pm

Crazy Frog

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Very good point.
The TPS overwrite the signal from the MAF.


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1986 k75, 1985 K100rt, 1985 K100rt/EML sidecar.
    

7Back to top Go down    Re: Fuel Pressure Regulator Test on Mon Sep 13, 2010 5:29 am

K-BIKE


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If you connect a vacuum pump to the vacuum line of just the FPR then you should be able to hold that vacuum indefinitely. If it is leaking down that means (assuming the gauge does not leak) that either the pipe to the FPR and or the FPR has a vacuum leak. Second-hand would be the lowest cost source
Regards,
K-BIKE

    

8Back to top Go down    Re: Fuel Pressure Regulator Test on Mon Sep 13, 2010 10:14 pm

Ned

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@8675k wrote:I performed this test at the onset of my problem which was overfueling of the the engine. My test indicated a delivery psi of 36. After testing and od replacing the electrical components in the system I am leaning toward the FPR. I realized a change in engine performance when I shook the regulator.
I alson cannot hold a vacuum on the reg when pulling a vacuum with a pump as ir there is a hole in the diaphragm? I can also restrict the feed side fuel line and the engine runs fine.

1. the only real test is to see if the 36psi fuel pressure holds for a reasonable time (several minutes should do it) after you switch the pump off (ignition off). if it holds the regulator is ok, if not, find what is leaking, it could be the regulator or something else in the high pressure circuit.
2. vacuum connection is not really required ... so you can just pull it off. I've not used it for a year or so and the bike runs just fine.
3. vacuum leak may be a simple tubing leak. you may want to replace it first before you junk a good pressure unit.


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Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

9Back to top Go down    Re: Fuel Pressure Regulator Test on Thu Sep 16, 2010 2:36 pm

8675k


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I want to thank everyone for thier input. I did find the regulator at fault by using an air induced setup! The fpr was intermittently allowing flow and when it was it performed erratically.
I was also able to find the regualtor in the aftermarket through Standard #PR-134 or NAPA #2-1709A At less than half the cost from BMW!
Thanks again to all!
JK

    

10Back to top Go down    Re: Fuel Pressure Regulator Test on Fri Sep 17, 2010 6:46 am

Crazy Frog

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As people have a hard time to locate the FPR, here is a picture of the beast and its location. The gravel on the engine comes as a bonus Razz


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1986 k75, 1985 K100rt, 1985 K100rt/EML sidecar.
    

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