VW Lupo Valveproblems

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Re: VW Lupo Valveproblems

Postby Steve Smith » Tue Jul 08, 2014 8:36 am

Thanks for the feedback again and for the additional waveforms.

I have just been thinking this through further (dangerous I know) looking at the peaks at the point of inlet valve open:

Cyl 1 270 mbar
Cyl2 656 mbar
Cyl 3 449 mbar
Cyl 4 461 mbar

Cylinder 1 being the lowest, I suspect number 1 cylinder inlet valve deformed. However why is there a peak at the point of number 1 inlet valve opening? (Could this be the effects of gas leaking past number 1 inlet valve or has an inlet valve from another cylinder received a kiss from the piston?)

What is interesting is the vacuum pockets too:

Cyl 1 186 mbar
Cyl2 220 mbar
Cyl 3 215 mbar
Cyl 4 193 mbar

Cylinder 1 being the lowest again.

If the engine is not to be dismantled can we do as Rob suggested and look at intake and exhaust pulsations?

It would be nice to remove the head with a couple of images as we can all learn from what we are seeing with the compression waveform.

Take care.....Steve
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Re: VW Lupo Valveproblems

Postby Chris C Stahl » Tue Jul 08, 2014 2:00 pm

Please try to keep track of want is wrong just for learning purposes

I am still learning the scope part to
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Re: VW Lupo Valveproblems

Postby terbo » Tue Jul 08, 2014 5:28 pm

Intake Pulsation should be no problem....but i don ´t think before the Weekend.
Cranking or running ?

Exhaust pulses i never had any look at....just throw in a pipe in the exhaust while
at running ?? Anything to do else ?
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Re: VW Lupo Valveproblems

Postby Chris C Stahl » Tue Jul 08, 2014 6:41 pm

If you are checking it again show us some running compression wave forms to
If you don,t mind. :) Thanks
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Re: VW Lupo Valveproblems

Postby terbo » Sat Jul 12, 2014 1:39 pm

Just for the fun of it ;) 2 hours with taking and laughing in the Sun - good Day ;)

Cranking and runing compressions attached - now Higher Range !

And Intakepressure from the Pressure sensor in the Manifold.
I tryed over 1 hour, but did not even get 1 reading from the
Intake or the Exhaust...maybe i did something wrong.
But i didn´t find any good Info or Video on doing so...

Yes, car idles very high, think about 1500 rpm, the belts for Alternator,power steering and so ar not
attached, and the Battery is going "down" because of no Alternator attached.

Cranking pics with Ignition and Fuel disabled, and throttle at the floor.
Attachments
intake-pressure-sensor-crank.psdata
Intake starting
(589.96 KiB) Downloaded 127 times
intake-pressure-sensor-run.psdata
Intake running
(2.62 MiB) Downloaded 138 times
z4-run.psdata
Cyl.4 running
(697.49 KiB) Downloaded 138 times
z4-start.psdata
Cyl. 4 starting
(627.72 KiB) Downloaded 130 times
z3-run.psdata
Cyl.3 running
(689.65 KiB) Downloaded 120 times
z3-start.psdata
Cyl. 3 starting
(624.29 KiB) Downloaded 125 times
z2-run.psdata
Cyl.2 runing
(689.61 KiB) Downloaded 131 times
z2-start.psdata
Cyl. 2 starting
(623.51 KiB) Downloaded 124 times
z1-run.psdata
Cyl.1 running
(698.05 KiB) Downloaded 158 times
z1-start.psdata
Cyl.1 starting
(609.78 KiB) Downloaded 126 times
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Re: VW Lupo Valveproblems

Postby Chris C Stahl » Sat Jul 12, 2014 4:46 pm

have a look with number 1 running the pressure spikes should be even it suggest an sealing issue
Also it can be seen on on intake cranking every 4th one the only thing there should be a refernce to a cyc I will look at them later
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