fuel pump priming

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r055
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fuel pump priming

Post by r055 » Thu Mar 29, 2007 12:50 pm

When turning the ignition on, should the fuel pump always make the priming noise?
Not so sure mine always does.
Im pretty certain the filter always makes the 'ticking' noise, but not always accompanied by the whirring of the fule pump.

Also, when you turn ignition on without immobilising, then you press the alarm button, should the pump prime then?
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hiscot
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Post by hiscot » Thu Mar 29, 2007 1:10 pm

it will only prime untill pressure is achieved
its also quite easy to replace and i believe a knackered one gets noisy before it goes
do a search I am sure i read that if you remove the fuel pipe and switch on you can measure how long it takes to fill a litre measure to check flow rate but disconect coils ect first
check its not a faulty mfu unit
i think there was a case of some faulty wire to the pump also

r055
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Post by r055 » Thu Mar 29, 2007 1:21 pm

Cheers

any ideas what the noise would be like if there wasnt any fuel getting to the pump? Would it be a higher pitched noise?

I have had problems with car cutting out and when trying to start again, the priming noise is not a consistent whirring noise like normal - more a broken up noise as if its straining.

EDIT: If i wait 5 minutes after it has cut out and won't start, it goes back to normal again.
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r10crw
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Post by r10crw » Thu Mar 29, 2007 4:11 pm

To my knowledge ther is no pressure switch on the pump. When you turn on the ignition the ecu should prime the system by activating the pump for a couple of seconds then stops. It doesnt then reactivate the pump until cranking commences. Wires feeding the pump are reallt easy to access (behind the seat under inspection panel)so best to use a probe tester and work the ignition. If it looks like the pump is faulty or youd like to try a good one give me shout I have a spare. Cheers Craig.

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robin
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Post by robin » Thu Mar 29, 2007 6:37 pm

Remember that the ECU primes the pump as soon as the ignition goes on, but if you haven't disabled the immob yet then you will effectively curtail the priming period.

If you have intermittent fuel pump problems I would start looking at the electrics, e.g. the immobiliser before worrying about the pump itself.

It's a 15 minute job to bypass the immobiliser temporarily (e.g. for a couple of days) to see if the problem "goes away".

Cheers,
Robin
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