97 mercury GRAND MARQUIS
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09-01-2024 | 03:06 PM
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97 mercury GRAND MARQUIS
help needed my brother called me today with this issue 1997 mercury GRAND MARQUIS 4.6 engine. any way he told me the car sometimes will not start right away when it sets overnight. he said he hears the fuel pump turn one and then off every time the key is turned to run. he put a gage on the fuel rail and got 37# when the key is turned on and then the pump stops. the pump must have a pressure switch built into it as i could not find one on rock auto. and when the engine runs he did not tell me that pressure but it must be close to that 37# as he said it drives perfectly down the road at speeds.
he said if he pulls the vac line from the fuel pressure control valve the pressure goes to about 55#. he also said if he keeps the gage on the rail for doing a pressure drop the pressure drops to about 3# from 11am to about 9pm. i believe that is a normal drop.
so i tried to find out of this car has an ignition relay, as if it does that may be starting to fail if not then what might i have him look at? i do not have the car in my garage. and trying to get him ideas is hard over the phone. he has a guy helping him there but they are out of ideas at this time.
i asked him a number of times if he could hear the fuel pump turn on every time he turned the key to on and he said yes and it then turned off by itself. that is normal. but it fails to start every time when it has sat overnight. he said after the first run and warmup it will start every time. also i told him to have his guy check the IAC. i did ask him if it will start every time if he presses the gas but it sounds like he is a bit confused on that point. as that could be the IAC.
so if anyone here has more places to check i sure would appreciate them. thanks
he said if he pulls the vac line from the fuel pressure control valve the pressure goes to about 55#. he also said if he keeps the gage on the rail for doing a pressure drop the pressure drops to about 3# from 11am to about 9pm. i believe that is a normal drop.
so i tried to find out of this car has an ignition relay, as if it does that may be starting to fail if not then what might i have him look at? i do not have the car in my garage. and trying to get him ideas is hard over the phone. he has a guy helping him there but they are out of ideas at this time.
i asked him a number of times if he could hear the fuel pump turn on every time he turned the key to on and he said yes and it then turned off by itself. that is normal. but it fails to start every time when it has sat overnight. he said after the first run and warmup it will start every time. also i told him to have his guy check the IAC. i did ask him if it will start every time if he presses the gas but it sounds like he is a bit confused on that point. as that could be the IAC.
so if anyone here has more places to check i sure would appreciate them. thanks
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