Fuel pressure too high (updated fuel pump internals)

Discussion of tuning specific to MAZDASPEED3/MAZDASPEED Axela/Mazda 3 MPS vehicles
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Steve @ VersaTune
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Joined: March 29th, 2010, 12:58 pm

Re: Fuel pressure too high (updated fuel pump internals)

Post by Steve @ VersaTune »

The pressure will spike when you shift. The injectors shut off and the fuel pump spill valve cant reduce pressure fast enough. It will sit at the relief valve open pressure until you open the throttle again or the pressure bleeds off. That's kind of normal with an upgraded pump. If it is hitting the relief valve open pressure under load, that's a problem.
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manselainen
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Joined: October 21st, 2011, 3:56 pm

Re: Fuel pressure too high (updated fuel pump internals)

Post by manselainen »

Cleaning of spill valve did not help. Pressure may still spike over 2000 psi also during boost. I'll try to make a clean log tomorrow. My fuel consumption is obviously too low :lol: need a bigger turbo...
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3 MPS '07, BNR S3, ported IM, VTCS delete, test pipe, PTP HPFP internals, RMM
06Speed6
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Joined: March 29th, 2010, 2:24 pm

Re: Fuel pressure too high (updated fuel pump internals)

Post by 06Speed6 »

Is the spill valve clocked properly to the body? If it isnt aligned right it doesnt work.
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manselainen
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Joined: October 21st, 2011, 3:56 pm

Re: Fuel pressure too high (updated fuel pump internals)

Post by manselainen »

Thanks for comments. First I just replaced the internals and didn't open spill valve but saw spikes. Afterwards I cleaned it and it should be clocked as before.

Anyway, attached is a log which seems pretty much OK? This time no spikes... I think I'll forget it for a while.

I think I'll do some fine tuning with MAF cal, in some points desired and actual are exactly the same but in some points there's difference. Then I might try upping timing. Or then I'll wait until spring... I would not like to destroy my new winter tyres...
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Tuned with Image by Image

3 MPS '07, BNR S3, ported IM, VTCS delete, test pipe, PTP HPFP internals, RMM
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