Fuel rail question

So the next part in the long list of parts I need to replace due to rust is the fuel rail. It is leaking at the front end cap. I ordered a new one from Jeep. The new one looks like it will bolt on but it doesn't have the pressure relief valve on it. Do you think this is a problem? Thanks.

Are you sure you're not referring to the Schrader valve? This is used mainly for diagnostic purposes to ensure the fuel rail is operating at the correct pressure. You can hook up a gauge to this port.

IIRC, the Renix systems use a bypass system that is always dumping fuel back into the tank at a certain rate so that the fuel pressure remains at the correct value (inlet pressure is constant). The vacuum-operated regular on the front of the rail controls this bypass operation.

On later XJs (such as my '98), there is no bypass -- the fuel pump duty cycle changes to arrive at the desired pressure.

If it's really a "pressure relief" valve that isn't there, maybe you have the wrong style of fuel rail.

Yes, I am referring to the schrader valve. The new rail does not have one. My cherokee is a '96 so it isn't a Renix. If the new rail doesn't have the valve, how do you release the pressure in the fuel system.

3pinr said:

If the new rail doesn't have the valve, how do you release the pressure in the fuel system.

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Hmm... for diagnostic purposes, I'm not sure. That's really weird there's not even a bung for the valve. I'd probably just pull the fuel pump relay while the engine's running. It won't get rid of all the gas, but it would help.