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1991 Volvo 740 Question: Starting issues

 

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Lawnboy, 4 Cylinder, Esmont, VA, August 28, 2009, 08:55
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I have an engine that won't start, its getting fuel pressure, but not to the engine. I replaced the fule pressure regulator, but it still isn't starting. I can hear the fule pump come on as well.

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    patrick mannion from Greg Solow's Engine Room, August 28, 2009, 09:19
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    Your car has two fuel pumps a low pressure pump in the fuel tank that pumps fuel to the main fuel pump at the left rear under side of the car. The fuel pump should be capable of putting out 43 psi of fuel pressure. With a fuel pressure gauge in the fuel line to the engine the system should hold 28 to 40 psi in the line (check valve holds fuel in the system). At one side of the fuel pump I believe the the is a rubber line that is secured by a hose clamp remove that hose fuel should just spill out . Reattach crack open the fuel line at the other side of the pump and get some one to crank over the car, you should have fuel under pressure coming out. Just next to the main pump is the fuel filter change that anyway from a maintainence point of view. The fuel pump relay is behind the ashtray in your car.
    Listen to the fuel injectors as someone cranks over the engine. You can listen to them by using a cheap mechanics stethoscope (Sears or any auto parts store) or use a long screw driver put the tip against the injector body near the electrical connector and put th handle end up against your ear you should hear the injectors sharply go click click click . The injectors have 12 volts at one side and get grounded by the Fuel/ignition computer in your car. The triggering is rapid and that's the sharp clicking you hear. No clicking means the ECU isn't triggering the injectors, this could be due to many reasons.

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