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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,265
Originally Posted by heliolps2 View Post
I have stupid Question , can any of these tests be done with the car running?
With a CIS pressure gauge kit connected in series with the control pressure line leading to the WUR and the ball valve open you can check control pressure while the motor is running.
If you close the ball valve to check system pressure in the WUR control pressure line the motor will go way lean from hydraulic control pressure raising way up and equaling system pressure and it will shut off or stumble alot and barely run from being way too lean but you'll get the system pressure reading as long as the pumps are running.

With the same CIS pressure gauge connected in series between the front and rear fuel pumps at the rear fuel pump inlet (same compression fittings as the WUR) like is being described in this picture with the ball valve open you can check the fuel pressure from the front pump while both pumps and the motor is running. Remove the rear fuel pump relay so only the front pump is running and you'll get an idea how well the rear pump is working but not the actual fuel pressure from both pumps running together at the same time.

Close the ball valve and the motor won't get any fuel and it will shut off but you'll get the static fuel pressure reading from the front pump while no fuel is going to the fuel head and being returned to the tank by the fuel head system pressure regulator or squirted out the injectors while the motor is running.
Old 11-29-2011, 07:34 AM
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