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rotorhead rotorhead is offline
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Join Date: Jul 2003
Location: Port Macquarie Australia
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Originally Posted by RarlyL8 View Post
So if the VR is overcharging at 3500rpm and you get on boost the spark can't take care of the extra fuel.
How does that relate to the temperature? The symptom is less severe when cold out, the air is more dense, so the A/F ratio is effectively raised enough to reduce the affect? That must be it. Interesting ....
OK Brian I get the sarcasm,

given the scenario there are a number of possible causes. I am not saying the VR is definitely the problem but it fitted all the listed symptoms.

- A failed VR will cause the tacho to fluctuate
- A dense mixture requires a strong spark to ignite (eg under boost)
- A failing VR can be temperature sensitive

When measuring voltage to determine a VR failure you have the let the battery recharge after starting the car. The Voltage will continue to climb and the high system voltage problem may only manifest itself after the battery has recharged from the start. (This is what appears to be the case in the last post)

Brian I am not going to defend my suggestion any further...( I too have a Type A personality)
2008 BMW 320i
2006 Mercedes ML320
2004 Mercedes ML270 cdi
1998 Porsche Boxter
1988 Porsche 930 Targa (sold)
Old 10-28-2007, 03:30 PM
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