Mechanics

MAZDA RX7 FUEL PUMP PROBLEM

1983 Mazda RX7 • 128,000 miles

My 1983 mazda rx7 wont start unless you pour gas in the carb please help
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Bthomas91
December 18, 2012.



You either have a bad fuel pump, fuel pump relay or the pressure regulator is bad.
Start by having someone turn the key to the "Run" position while you stnad near the fuel tank as close to where the fuel pump is. It should come on for a second or two to Prime the sytem. If you don't hear it, replace the relay as it is the first step in the process of elimination. If that does not work then you should check the fuel pump wires to suee if you are getting 12 volts to the pump. You will have to drop the tank or sometimes you can access the pump housing under the rear seat.
If you are getting 12 volts then the pump is bad.

I can hear the fuel pump come on so where is the pressure regulator at? Thanks for the help

Tiny
Bthomas91
Dec 18, 2012.
The regulator will be on the return fuel line near the manifold. Just follow the fuel rail which sits above the fuel injectors and figure out which way is in and trace it around and you will see a part with a vacuum line attached to it and it willl be attached to the fuel rail. This is the return line and that is the pressure regulator.
If your pump is turning, I would go ahead and check the fuel pressure next.
Advance Auto ro Auto zone loan out test tools for testing fuel pressure. You will see a valve on the fuel rail which is where you will take reading from. There will be adapters in kit. Make sure car sits for a while so fuel pressure drops and still cover with rag whenever opening fuel system in case there is risidual pressure.