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914World.com _ 914World Garage _ Timing question - plugging the vacuum advance hose
Posted by: john_g Jan 11 2013, 04:15 PM
I have only had experience using John Muir's static timing method with VW's, so am not used to the strobe light procedure for the 914. So, I have a number of questions:
1) To get a starting point, using a static timing light or voltmeter, what's the static timing mark to use with a '74 2.0 engine - 5º or 7.5º?
2) Before using the strobe light, some instructions say to remove the vacuum hose from the distributor, others say to remove AND plug it with something. What's correct? And, if I plug it, do I plug the hose end or the connector to the distributor, or both? 
Thanks.
Posted by: SLITS Jan 11 2013, 04:39 PM
2.0L engine .... 27 degrees @ 3000 RPM** is what I use. No static numbers published as far as I know.
On a 74, there is only Vac Retard ... Vac Advance is not hooked up. You plug the line so that your idle doesn't go up from the vacuum leak you create. Plug the hose with a pen or pencil so that you don't have an open vac leak at the throttle body.
** Some say 3500 RPM, but as far as I am concerned, all mechanical advance should be in at 3000.
Posted by: john_g Jan 11 2013, 04:58 PM
Thanks. So ... I only plug the hose end, not the connection to the distributor, right?
Posted by: rmital Jan 11 2013, 05:13 PM
Thanks. So ... I only plug the hose end, not the connection to the distributor, right?
Correct, and I like to use a golf tee to plug the hose
Posted by: SLITS Jan 11 2013, 05:40 PM
Thanks. So ... I only plug the hose end, not the connection to the distributor, right?
Correct, and I like to use a golf tee to plug the hose
Sorry Ray ... I don't chase little white balls around a Cow Pasture ...
Posted by: Dave_Darling Jan 11 2013, 07:52 PM
Just use TDC as a static timing point; it should get you close enough for the engine to run.
With the D-jet system, you don't actually have to plug the vacuum line. It's good practice, though, since leaving it unplugged can cause problems with L-jet or carbs. It also keeps un-filtered air from getting into the engine, which can be nice if you live in a dusty area.
--DD
Posted by: john_g Jan 13 2013, 04:37 PM
Just use TDC as a static timing point; it should get you close enough for the engine to run.
With the D-jet system, you don't actually have to plug the vacuum line. It's good practice, though, since leaving it unplugged can cause problems with L-jet or carbs. It also keeps un-filtered air from getting into the engine, which can be nice if you live in a dusty area.
--DD
Thanks - that jives with the Haynes manual which just says to disconnect the hose and says nothing about plugging it.
Posted by: last337 Jan 13 2013, 05:11 PM
Where is the vacuum connection you guys are talking about? I have nothing going to my carbs or distributor but not sure where then original vacuum connection was. Any pics?
Posted by: Dave_Darling Jan 13 2013, 05:44 PM
We're talking specifically about D-jetronic fuel injection. Carbs are a different beast.
On the original injected motors, there was a vacuum dashpot on the side of the distributor. Most 914s had two hoses connected to the dashpot; one vacuum retard line that went from the fitting pointing toward the distributor body to the throttle body after the throttle plate, and the other a vacuum advance line that went from the fitting pointing away from the distributor body to the throttle body before the throttle plate.
Carbs usually don't have the fittings for either of those. And more often than not, the distributors are replaced when carb conversion is done so that the distributors don't have the vacuum dashpot either. So don't worry about them.
--DD
Posted by: last337 Jan 13 2013, 07:04 PM
We're talking specifically about D-jetronic fuel injection. Carbs are a different beast.
On the original injected motors, there was a vacuum dashpot on the side of the distributor. Most 914s had two hoses connected to the dashpot; one vacuum retard line that went from the fitting pointing toward the distributor body to the throttle body after the throttle plate, and the other a vacuum advance line that went from the fitting pointing away from the distributor body to the throttle body before the throttle plate.
Carbs usually don't have the fittings for either of those. And more often than not, the distributors are replaced when carb conversion is done so that the distributors don't have the vacuum dashpot either. So don't worry about them.
--DD
Thanks for reply. I was wondering what the spot is for a hose next to the #2 spark plug. I don't have anything plugged in there but looks like something should go there
Posted by: Dave_Darling Jan 13 2013, 09:37 PM
The #2 plug? That doesn't sound familiar. Is it on the carb manifold, or coming out of the head, or something else? If it's coming out of the head, then it's for the Positive Crankcase Ventilation system.
--DD
Posted by: last337 Jan 14 2013, 09:47 AM
The #2 plug? That doesn't sound familiar. Is it on the carb manifold, or coming out of the head, or something else? If it's coming out of the head, then it's for the Positive Crankcase Ventilation system.
--DD
I was talking about this one right next to that with the braided hose on it. That hose doesnt appear to go anywhere after that. It just goes into the cover it looks like.
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