| Mulcheese |
Sat Jul 30, 2005 6:19 am |
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| Is it possible to check/set the timing advance with out a tach. I have an old bench analyzer and the tach only reaches 2000/rpm. |
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| Randy in Maine |
Sat Jul 30, 2005 7:17 am |
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Ideallly you would pull of the vacuum hoses (leave open) and wind it up to 3000 RPMs. You want to be no more than 28* advanced at that point.
I would hook up the light and take it to 2000 then go some more to see where it is all in a 28* and then let it drop down to idle and see where you are at. Should be pretty close to the spec.
Really you are looking for a nice smooth advance and retard curve with the light and the timing scale. Lot to be said for clening the inerds of the distributor and re-lubing the pivot plate with some Bosch distributor grease (about $5 for a tube I think).
If you are using points, putting a drop of engine oil on the little pad around the shaft is nice to do. |
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| Mulcheese |
Sun Jul 31, 2005 6:03 am |
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When I set the timing at idle I did not pull any hoses. should I be doing that or pull hoses only when checking advance? And which hoses should I pull?
When I use my bench analyzer to check RPM's I hook it up to the pos. and neg. terminals of the coil. Is that right? |
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| mightyart |
Sun Jul 31, 2005 7:09 am |
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The older Bentleys tell you to pull and plug the vac. advance hose.
This is wrong and was later revised. when checking the timing leave all hoses ON.
I think the pos. (red or alot of tacs are green) goes to the - or negitive on the coil. The black wire goes to body. This is how basic tacs hook up yours might be different. |
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| Randy in Maine |
Sun Jul 31, 2005 6:26 pm |
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Sorry I have been out all day. Porsche show \:D/
On my tach/dwell, I hook mine up this way, the green or red clamp to the to the green wire side of the coil (that also has the white wire coming in from the ECU) and the black clamp to the engine gound (I use the bolt that holds the coil to the engine.
When timing the vacuum hose should be connected as per the Old Volks home spec.
"Timing Set At:: 7.5deg BTDC @ 850-950 rpm (Man Trans), 900-1000 rpm (Auto Trans) w/strobe, vacuum hose connected. (Bentley Table on Page 28.3 incorrectly states with hose disconnected).
Advance/Retard Range: Vacuum: 8-12deg Adv @ 7.9 In. Hg; Centrifugal: 9-14deg @ 1600 rpm, 21-25deg @ 3400 rpm"
When seeing what the max advance the distributor is putting out at 3000 RPM, the vacuum line is diconnected from the distributor (to remove any additional vacuum advance after max centricial advance). As we are all aware a stock SVDA dizzy with a type 4 engine is capable of putting out more than 30* total advance at partial throttle and up to 44* (if I recall correctly and which is why a 009 dizzy is so lousy in a type 4), so we want to remove the vacuum function to see if it is advancing like it is supposed to. |
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