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How do you check your fuel pressure on the RX8?

Old 05-14-2014, 04:07 PM
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FL How do you check your fuel pressure on the RX8?

I need someone's assistance. I am trying to check if I need a new fuel pump for my 8. I bought a fuel pump tester but I am not sure how to do the test. Does the 8 have a test port in the engine bay or do I have to connect the tester to the pump under the rear passenger seat. Please help! I could not find anything on testing. The only thing I found was on how to change the pump.

Your assistance is greatly needed.
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Old 05-14-2014, 04:13 PM
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The easiest way is to disconnect the fuel line near the brake master cylinder and put an adapter inline at that location.
You can get away with a piece of metal fuel line with the correct end on one end...and a hose on the other end to attach to the metal fuel rail...or you can buy an adapter that has the required fittings that have an 1/8NPT gauge port on it
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Old 05-14-2014, 06:26 PM
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Old 05-14-2014, 06:43 PM
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Per Alldata


WARNING: Fuel line spills and leakage from the pressurized fuel system are dangerous. Fuel can ignite and cause serious injury or death and damage. To prevent this, complete the following inspection with the engine stopped.

1.Follow the before repair procedure and perform the fuel line safety procedure.
2.Disconnect the negative battery cable.
3.Disconnect the engine compartment side quick release connector.
4.Turn the lever of the SST parallel to the hose
5.Reconnect the quick release connector of the SST to the fuel pipe until a click is heard.
6.Verify that the quick release connector is firmly connected by pulling it by hand.
7.Connect the negative battery cable.

CAUTION: Shorting the wrong terminal of the check connector may cause malfunctions. Make sure to short only the specified terminal.

8.Ground the check connector terminal F/P using the jumper wire.
9.Turn the ignition switch to the ON position and operate the fuel pump.
10.Measure the fuel line pressure.

•If not within the specification, inspect or replace the following parts: If it is less than the specification
•Fuel pump unit
•Fuel line leakage

If it is more than the specification

•Fuel pump unit
•Fuel line clogging

Fuel line pressure: 375 - 450 kPa {3.83 - 4.58 kgf/, 54.4 - 65.2 psi}

11.Disconnect the jumper wire and stop the fuel pump.
12.Wait 5 min and measure the fuel hold pressure.
•If it is within the specification, inspect the following.
•Fuel line for clogging or leakage

Fuel hold pressure: 200 kPa {2.0 kgf/, 29 psi}

13.Disconnect the SST.
14.Connect the quick release connector.
15.Inspect all parts by performing the "AFTER REPAIR PROCEDURE

Last edited by EuroTech; 05-14-2014 at 06:47 PM.
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Old 05-14-2014, 09:08 PM
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Originally Posted by quickimpact View Post
Your assistance is greatly needed.
well if you had used this - Search Forums

you would have found this from only two weeks ago half way down the page

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Old 03-29-2017, 05:26 PM
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I am curious, does anyone know why the instructions for the Fuel Line Pressure Inspection state that check connector terminal F/P should be shorted to ground rather than simply to the other terminal in the check connector, which is a ground wire based on my review of the wiring diagrams and the fact that the wire is black? If I am correct, the "malfunction" due to shorting the incorrect wire would be that fuel pump would not operate. This seems so simple that I wonder if I am overlooking something.
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