Hi all,
I’m after I little information regarding the functionality of the fuel pressure regulator, if someone could please assist.
I’m having starting and idle running issues so I’ve been testing a series of things and currently on with testing the fuel rail of my mk1 1.6. I’ve attached a pressure gauge inline just before the rail. I’ve done a static pressure test with just the ignition on (not running) and the pressures holds at 45 psi.
My question is, when I then turn the ignition off the pressure drops to zero draining via the regulator. Should the pressure hold at 45 psi with the ignition off? I’m thinking the regulator might be stuck open.
The pressure will drop slowly if it’s going down quickly then it could be a leaky injector or the regulator to check the injectors you can take them out out of the engine and reconnect them to the fuel rail then cycle the ignition on off a couple of times to build up pressure then ignition off check for drips out of the tips
Hope this helps
It drains from 45psi to zero in around 5 seconds after the ignition is off, would you describe that as fast?
I’ve taken the inlet off and there isn’t an injector leak when they are under pressure. I’ve also just tested to see what the spray is like when turning the engine over. There’s one decent spray to start then the others that follow have much less fuel volume.
The fuel pressure should remain above 21psi for at least 5 minutes so yours is dropping too quickly. If you clamp the feed and return hoses does it hold for longer?
Yes clamping the return pipe holds the pressure for about 3 minutes. So are all indications pointing to a faulty regulator?