Timing Advance Mod

[SolarSteve]

I have read the Timing Advance Mod thread a number of times and I still am not sure of exatly where this cover that needs to be removed to get to the spring is located.  I just took a look at an enlarged parts breakdown of the IP and the only place I see a spring like the one mentioned in the mod is down very low on the front side.  Is this what I am looking for?  I have looked at my IP several times and did not notice any covers on the front side of the pump, but after seeing this parts breakdown I will look again.

Thanks

[rabbitman]

Yup that's the one. Although as long as the advance is in spec I don't see the point in messing with the shims. Rather it seems like making sure the internal pressure is up to spec first.

BUT, if you do feel like messing with the shims be sure you write down how many shims you took out/added and how far off the internal pressure was etc....I didn't and it's been a constant joy trying to get it right again.

If you want more advance and your internal pressure's low removing shims will help, but it's better to bump it up to where it's supposed to be.
http://www.vwdieselparts.com/forum/viewtopic.php?t=5936

[SolarSteve]

The pump on the Jetta(1991 N/A) has a cylindrical shaped device, possibly a solenoid, with a very small steel line coming out of the left side (while you are facing the motor) and a electrical connection on the right side.  This is bolted to the cover for the advance spring.  The pump on my spare engine that came out of a 1990 N/A Golf does not have this at all.

Does anyone know what this decive is and what it is for?

Thanks