Mechanics

NO START ON MY 99

1999 Mercury Cougar

Ok so my 99 cougar wont start I have checked all the relays replaced the fuel pump charged and replaced the battery what happens it when I turn the elctronics position the fuel pump surges then cuts off put a pressure gage on the fuel rail and it only reads like 10psi and then you have to build it up by cutting the key on and off car still wont start please help?


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Killrock77
September 9, 2012.



The fuel pump would only prime for a few seconds when ignitin switch is turned on.

The low fuel pressure could be due to a bad fuel pump or a fault with the fuel pressure regulator.

Pinch the return hose at fuel pressure regulator and cycle the ignition switch a few times and check the fuel pressure again.

KHLow2008
Sep 9, 2012.
Where is the regulator?

Tiny
Killrock77
Sep 9, 2012.
Which engine do you have? It should be on the fuel rail.

KHLow2008
Sep 10, 2012.
Its the 2.5 v6

Tiny
Killrock77
Sep 10, 2012.
The fuel pressure regulator is downstream of the fuel rail. It has a vacuum hose and a return line for excess fuel to return to tank.

Clamping the return hose would prevent fuel from returning and if the pressure regulator is faulty, the pressure would increase.

KHLow2008
Sep 10, 2012.