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<x-charset iso-8859-1>Jim A. wrote: > > A while back I wrote about having a problem with hesitation on > > acceleration, under load. MY car is a Carb'ed '69 T34. > > Are they the OE carbs and the OE dist? If not, what are they? > All stock, though may be from a later year - Dist. - 311 905 205 T ?! > > Well, after checking the carb for vacuum at different rev's and > > checking the distributor for advance at different vacuums I've > > reached the conclusion that I'm getting to much advance, to soon. > > My carbs are new and are giving 200mmHg vacuum at 1500r.p.m and > > 300mmHg at 2000r.p.m. - according to the Bentley for a similar > > distributor this vacuum should only be reached at 3000r.p.m > > (crankshaft). > > You have to be careful when making comparisons between curves > of different carbs/dists. The Bentley only covers the FI dists. Also, > the Bentley graphs are taken straight from the Bosch literature, but > they are NOT intended for you to make translations from vacuum to > RPM. They are only written that way to allow the graphs to be > compact and still allow you to read the mechanical advance as a > function of the RPM and the vacuum advance as a function of the > vacuum. Let me clarify, I only read the graphs as vacuum to vacuum advance and then in a general way. About the vacuum at RPM I measure it by connecting my vacuum gauge to the outlet (stock PDSIT's ) and watching the tach, as I rev it. > > > This is confirmed by the car performing very well, on uphills > > (under load) it runs well at about a 1/3 pedal, but lousy above > > that, worse, the more I put my foot down - I hear a Brrrr... sound > > from the back - I guess this is pinging?! > > Probably not pinging. I'm guessing that it's more likely that you just > don't have the right advance at those RPMs. It's possible that you > have a mismatched dist and carbs and that they don't work > correctly together. > > You might find it instructive to put a Tee in your vacuum advance > line and run a gauge into the car. That way you can see what the > pressure REALLY is when things are running well and running > poorly. I suspect that you will be surprised. > I'll try this. . > > > So, what is the solution, less static advance i.e. set advance to > > 3 deg. BTCD instead of the current 7.5 BTCD ? > > Is 7.5 BTDC the correct setting for your car, or did you come to > this conclusion based on some info that you used to come up with > a timing scheme for your non-stock setup? > This is the correct timing for the Stock setup I have for a '69 (Actually for all the dual carb setup's) Herman ------------------------------------------------------------------- Unsubscribe? mailto:type3-request@vwtype3.org, Subject: unsubscribe </x-charset>