Fuel Pump Query

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maxstu
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Fuel Pump Query

Post by maxstu »

DJ 2.1 Auto.
Initial question is....will l hear noise or feel vibration from standard electric fuel pump with ignition switched on, but engine not running?
I can hear swirling noise from pump once engine is actually running. Yet l thought once key is set to dash lights on, pump would activate and be audible
Today engine cut out at junction (as if switched off) and intially refused to start. Then after 5 minutes fired up. Then repeated failure two miles on. This time refused to start for 30 minutes.
My thought is fuel pump beginning to fail?
Your views please
Thanks
Stuart
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1989 DJ 2.1 Auto Leisuredrive rusty bucket.
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bigherb
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Re: Fuel Pump Query

Post by bigherb »

In short no, the pump only runs when the ECH receives a signal from the ignition system that the engine is rotating.
If you are losing the spark that would also switch off the pump.
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maxstu
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Re: Fuel Pump Query

Post by maxstu »

Nice one Bigherb :ok

So turning over engine on ignition, providing a spark is present, should bring forth swirling from pump.
I may start looking for poor connection somewhere.
Kindest regards
Stuart
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1989 DJ 2.1 Auto Leisuredrive rusty bucket.
"Blissfully happy in your presence".

adie89
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Re: Fuel Pump Query

Post by adie89 »

If your pump is running check for blockages. The fact that it starts, runs then cuts out and restarts later could also suggest a blockage on the fuel lines. Fuel is draining past the blockage enough to run for a bit, but not enough. When you stop it starts to seep past the blockage again to give you enough to restart and run again. Take the fuel line off the injector rail, put it in a bottle then flick the ignition on, should get a healthy flow.
Also check for leaky lines, if your drawing air in it will cause problems, although less likely than pump or blockages.
On ignition on the pump should run, prime the lines and then stop until the pressure drops again once the engine actually starts.
Could also be your ignition amplifier, as it gets hot it will fail, it then cools and allows you to restart, you would have to check for spark immediately after a cut out to check for that, it don’t know how to test the amp with a multimeter.
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