When it comes to ignition timing, they always say to set the idle first, and then check the timing. Okay fine... but your timing also affects the idle speed, so how do you "de-couple" them?
In other words, on my fuel injected 1975 VW bus (with an upgraded 2.0L engine, which uses the original 1.8L distributor), the timing at idle is 5 ATDC. And I always check not to exceed 32 degrees at 3500RPM... okay fine. But I have noticed that if my idle speed is low, and my timing is slightly retarded, I can do two things that give identical results, but different performance:
First off .. you have some facts confooooosed.... 32 Deg at WOT is for typeI engines with 009 distributors.. not T4 engines with factory distributors
sooo.. start off....
always set your timing first,, fuel last.. i.e. replace tune up parts,, set valves, dwell,, timing, then idle....
set you Dwell at 50 .... then set your timing with no advance at spec. to be 7.5deg BTDC
then adjust your idle . so you have the correct idle. 850-950 rpm Man. Trans
Then check your WOT full advance.. and I bet you will see it goes to about 43 deg .... perfectly to specs.
You may not have the correct distributor.. you can check the specs of the distributor you have using this pagehttp://www.oldvolkshome.com/ovhignbo.htm
then you can see what the full advance will be for the dist your using..
Also, my distributor has a dual vaccum line connection. The vaccum lines both retard (at idle) and advance. I thought I read somewhere that these latter day VW distributors should be allowed a bigger advance at full throttle (relative to the standard 009 centrifigul advance), but I have not been able to confirm this.
To make matters more confusing, my whole engine set-up is somewhat "bastardized" (non-stock). I am running a 1975 distributor (I think), computer, and flow meter, with a 1978 2.0L engine. The original 2.0L engine had 7.5 BTDC timing at idle. I have a modified transmission with higher 3rd and 4th gears. So I can easily cruise down the freeway at 70 MPH with my foot barely on the pedal, and pulling less than 3500 RPM's, so it seems i should be able to advance it a tad more than normal.- Tony
Most likely you have a different 4th,, and R&P ,, sounds like the 4.57 R&P and the ).82 4th...but a stock 3rd, unless you know what gear set was installed....
Do NOT advance the distributor ,, unless you have a CHT gauge .... as it will run tooo hot unless you richen the mixture significantly..
the only diff between a early 2liter and a late 2liter is hydraulic lifters... which makes no difference to the dist or the idle bypass settings
The retard part of the dist will alter the WOT setting as you drive..
if you want more info.. subscribe to type2.com list.. and ask ... the experts there , who will set your mind at ease.
Hope that helps