[DML] Re: pinging and ignition advance

["David Teitelbaum" <jtrealty@xxxxxxxxxxxxx>]

Timing advance can be checked with a tachometer and a timing light.
Pinging can be caused by bad gas, carbon deposits, overheating,
running too lean a mixture, wrong spark plugs to name a few causes.
Total advance (with vacuum AND mechanical) should be 40, not 22. Make
sure you are getting ALL of your mechanical advance and all of your
vacuum advance. I have seen where the mechanical advance gets stuck
and you don't get any and I have seen problems in the vacuum circuit
and no vacuum advance. One of your timing advance systems is not
functioning. Very easy to check, disconnect the vacuum line to the
distributer and see if you get any advance. If you do then you know
the vacuum is the problem. Verify the markings for TDC on the scale
and make sure your initial (base) timing is correctly set @ 13
degrees. Refer to M:01:04 in your Workshop Manual. A vacuum hand pump
is not expensive and would make it much easier to troubleshoot your
vacuum circuit.
David Teitelbaum
vin 10757



--- In dmcnews@xxxxxxxxxxxxxxx, Jason Ferrara <jason@...> wrote:
>
> 
> My car is pinging at high RPMS under heavy acceleration. So I checked  
> the timing.
> 
> The centrifugal advance at 4000 rpm is 22 degrees instead of 20.  
> Would this be enough to cause the pinging, or is that within normal  
> tolerances?
> 
> Is there a way to check the vacuum advance without a vacuum pump?
> 
> Thanks
> 
> - J
>









To address comments privately to the moderating team, please address:
moderators@xxxxxxxxxxx

For more info on the list, tech articles, cars for sale see www.dmcnews.com

To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/dmcnews/

<*> To unsubscribe from this group, send an email to:
    dmcnews-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/