With ALS ON engine ocasionaly misfires

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FS2000
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With ALS ON engine ocasionaly misfires

Post by FS2000 » Fri Dec 20, 2013 5:19 pm

Hi,

We have a EVO 9 that ocasionaly misfires only when the ALS switch is ON and only right after the bang bang when you press the throttle down. Other than that there is no misfire at all.
Car is runing a GEMS ECU.

Hope some one can help.

Thanks,

Carlos

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RickS
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Re: With ALS ON engine ocasionaly misfires

Post by RickS » Thu Jan 02, 2014 9:33 am

Hi,
Hard to give you a definitive answer without seeing the calibration or a telemetry log but possible causes could be overfuelling when restoring the fuelling and ignition values, coil not 'loading' quickly enough, compression drop.... It's hard to tell.

Is this a brief misfire or does it last for several revolutions....?

If you feel the need, don't post your calibration here but send it to tech (dot) support (at) gems.co.uk

Best regards,
RickS.......

FS2000
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Posts:2
Joined:Fri Dec 20, 2013 5:04 pm

Re: With ALS ON engine ocasionaly misfires

Post by FS2000 » Thu Jan 02, 2014 9:59 pm

Hi Rick,

Yes, it lasts for several revolutions, from time to time.

We have changed coils, plugs and injectors, but without success.

Sent you a log.

Thanks
Carlos

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RickS
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Re: With ALS ON engine ocasionaly misfires

Post by RickS » Mon Apr 14, 2014 3:50 pm

On my test bench, I have managed to get a 9 to misire inconsistantly at large throttle openings only but yours appears to be at various openings.

If it was happening regardless of ALS activity, I would suggest an injection driver problem but you say that it's OK out of ALS. I have to say that I will have to ask for someone else to have a look at the traces that you sent over, as a fresh pair of eyes might spot something that I have missed. I suppose that you have replaced the ALS switch...?

I will get back to you as soon as I have more information.

BR, RickS

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