Any way to pressure test fuel line connections on rails/tee prior to reinstalling mot

[BrakeL8]

About to put the motor back in my first engine drop that spiraled into basically everything short of separating cases.

Question- the Paul Mason fuel line kit has a threaded tee to connect the right and left rail feeds - something that if it’s leaking I can’t imagine I can tighten without pulling intake manifold or re-dropping motor

Is there a way via some tool to pressure check these fuel line connections to know that they’re good before I re-install?

Thanks!


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[88911coupe]

Bump..I have the same question...I did a search and didn't find an answer. Maybe I didn't use right words.

[Schulisco]

Pragmatic approach by an experienced german Porsche specialist from Cologne: Put the engine back in the car, connect all lines, put 20l/5gals gas in the tank, bridge the fuel pump and let it run for at least half an hour without starting the engine. This pressurizes all fuel lines without the fear of catching fire by a leak due to a hot engine. So you can watch for leaks pretty relaxed.
If this test was successful, you can start the engine as next step.
Thomas

[boyt911sc]

You can test the whole engine or individual fuel line or a combination of fuel lines using a fuel pump, pressure gauge and shut-off valves. You can use the fuel pump in your car or have a separate portable FP to pressurize your fuel line/s. A fuel tank as small as a gallon capacity would be sufficient to do the pressure test. It would only require several seconds to do the test or long enough for visual inspection.

Tony

[rwest]

Could you add an air fitting on the other end of the rails; is there a plug on the other side of your rails?

Put less air on the system than the injectors open at and then spray soapy water over all your fittings.

Just a thought, I haven’t ever tried this.

[BrakeL8]

Originally Posted by boyt911sc

You can test the whole engine or individual fuel line or a combination of fuel lines using a fuel pump, pressure gauge and shut-off valves. You can use the fuel pump in your car or have a separate portable FP to pressurize your fuel line/s. A fuel tank as small as a gallon capacity would be sufficient to do the pressure test. It would only require several seconds to do the test or long enough for visual inspection.

Tony

Thanks Tony-

Let me ask a dumb question here - I presume if I do this with the engine out of the car it would just run down the rails past the injectors and back out the return line.

Would I damage anything with a cap on the return line? Want to ensure I don’t overpressurize OR should I just run the return back into the same fuel source so it’s a closed loop similar to the car?

Want to check out of the car if possible to verifying all the new connections are solid prior to re-installing and then needing worst case to re-drop the motor.

[BrakeL8]

Originally Posted by rwest

Could you add an air fitting on the other end of the rails; is there a plug on the other side of your rails?

Put less air on the system than the injectors open at and then spray soapy water over all your fittings.

Just a thought, I haven’t ever tried this.

This was exactly what I was wondering if could be done without harm. Just to validate things are not leaking.

[boyt911sc]

Originally Posted by BrakeL8

Thanks Tony-

Let me ask a dumb question here - I presume if I do this with the engine out of the car it would just run down the rails past the injectors and back out the return line.

Would I damage anything with a cap on the return line? Want to ensure I don’t overpressurize OR should I just run the return back into the same fuel source so it’s a closed loop similar to the car?

Want to check out of the car if possible to verifying all the new connections are solid prior to re-installing and then needing worst case to re-drop the motor.

You could do the pressure test with the motor installed or not. The main thing is to connect the fuel delivery line to the fuel lines or motor and test run the fuel pump. Place the motor in the engine bay without bolting it to the car. And perform the pressure test. The return line should be connected too.

Install a pressure gauge at the test port by cylinder #1 so you have an idea how much pressure you did the test. The FPR (fuel pressure regulator) will control the system pressure under 40 psi. and the pressure gauge could confirm if your FPR is good or bad.

Do you know how to test run the FP for Carrera 3.2 motor using S6 and S7 (fuses)?

Tony

[88911coupe]

Tony, can you explain how to "test run" the fuel pump on a 3.2? I just had the "J" shaped fuel line rebuilt on my '88 (engine is out for new clutch, PP and disc). I decided to have the rubber parts replace by a race shop here in town and would like to make sure there are no leaks. I assume I'll need to at least partially reinstall the engine, at least to get the fuel lines Hooked up.

[boyt911sc]

Originally Posted by 88911coupe

Tony, can you explain how to "test run" the fuel pump on a 3.2? I just had the "J" shaped fuel line rebuilt on my '88 (engine is out for new clutch, PP and disc). I decided to have the rubber parts replace by a race shop here in town and would like to make sure there are no leaks. I assume I'll need to at least partially reinstall the engine, at least to get the fuel lines Hooked up.

Buck,

There is a test port located at the fuel rail near intake #1. This is where you connect a pressure gauge to test fuel pressure of the system with the motor running or just the FP. If you are interested to test the fuel pressure without the motor running, you can do it with just FP running and motor OFF.

Locate the 16th and 17th fuses counting from the front of the car or 6th and 7th fuses counting from the windshield. Use a suitable wire jumper to bridge or connect these fuses and the fuel pump will RUN.

This is how you test run the FP for Carrera 3.2 cars. Jumper wire with alligator clips will be sufficient to make the FP test run easy and safe. Please let me know if you still need some clarification and guidance.

Tony

[88911coupe]

Tony, thanks, that is simple enough that even I can follow the instructions! This will allow me to test pressure AND for leaks.

[boyt911sc]

Originally Posted by 88911coupe

Tony, thanks, that is simple enough that even I can follow the instructions! This will allow me to test pressure AND for leaks.

Buck,

If you just want to test for leaks of the fuel lines system, all you need to do is jumper FUSES #6 & #7 (counting from the windshield). No need to turn the ignition switch as long as the battery is connected. If you could fabricated the jumper wire with an IN-LINE fuse, the better. It is optional.

Tony