Volvo v70 misfire

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bullstar
OneWave
OneWave
Posts: 29
Joined: Wed Nov 21, 2012 9:48 pm

Volvo v70 misfire

Post by bullstar »

Hi, Just bought a wps so thought I would try it on a misfiring Volvo 1999 model 10 valve, following the software instructions I did a compression test, the figures on all 5 cyls were identical around 167 psi but I'm not sure what the small peaks are , is this a valve reading?
with a vacuum gauge I'm reading 13 inHG steady, valve timing ?
done vacuum test also with wps , used zoom, see pics
Attachments
volvo v70 cyl relative compression.psdata
(469.5 KiB) Downloaded 499 times
volvo v70 intake vacuum test.psdata
(924.97 KiB) Downloaded 508 times
volvo v70 zoom range 3.psdata
(348.7 KiB) Downloaded 441 times
volvo v70 cyl 1 compression test.psdata
(199.15 KiB) Downloaded 497 times

volrem
TwoWaves
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Location: Estonia

Re: Volvo v70 misfire

Post by volrem »

I would say that this small peak (0,8 bar) is because exhaust valve closes too early.

bullstar
OneWave
OneWave
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Joined: Wed Nov 21, 2012 9:48 pm

Re: Volvo v70 misfire

Post by bullstar »

Thanks for your input, I was thinking it was the exhaust stoke as if I put the rulers up in degrees from compression peak to peak 720 degrees the 0.8 bar is in exhaust stroke, Surely There should be no peak on a compression test

andrewbishop66
TwoWaves
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Re: Volvo v70 misfire

Post by andrewbishop66 »

Hi
how about cylinder leak back test the peak could be due to leaking valves on its companion cylinder causing the pressure increase

Thanks andrew

andrewbishop66
TwoWaves
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Re: Volvo v70 misfire

Post by andrewbishop66 »

dont know if this helps
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Untitled.png

bullstar
OneWave
OneWave
Posts: 29
Joined: Wed Nov 21, 2012 9:48 pm

Re: Volvo v70 misfire

Post by bullstar »

Hi, thanks for your input , yes a cylinder leakage is the next test we going to do on this car , I believe the car is similar to the test results as the valve train also sounds a little noisy and could be the symptoms of valve lash.

volrem
TwoWaves
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Location: Estonia

Re: Volvo v70 misfire

Post by volrem »

Measure cam and crank to see if timing is off.

victor2k
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Re: Volvo v70 misfire

Post by victor2k »

Hello,
Or check the cylinder pressure waveforms for all cylinders to see the wear of exhaust camshaft.
Regards

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