Injection pump question (what's this part do?)

[DRP67207]

Hello all.

So my injection pump is leaking fuel out the back, I believe where the cold start lever goes in.  I have a reseal kit to replace those couple o-rings (I'm going to hold off on replacing any other seals until they start leaking, if it ain't broke...).  Anyways, I was poking around there, trying to assess the situation and plan my attack, and noticed that the cold start lever on this pump (supposedly an '84 Jetta engine) was different than a spare pump i have off an '81 caddy.  As the pictures below shows, it has a rod connecting to a pivoting mechanism above it with two adjustable stop screws.  I was just wondering what this part is, and how it affects the injection pump when you pull the cold start lever.





The pump from the '81 (below) has no such mechanism. 


Why the addition and how does it help the injection system? (I assume it's some "improvement" added on later models) Just curious.

Thanks in advance for any insight.

[coke]

That is a two part system. One increases idle speed, and one increases cold start. Its from a later model A2 / MK2 vehicle.

[Vincent Waldon]

... and so one of those screws with the locknut sets the normal idle speed, and the other sets the "fast idle when the cold start handle is pulled" speed.

The normal idle speed is also affected by the length of the pushrod... adjusted by turning the screw on the left of your first picture with the coiled spring.

[Dakotakid]

If you decide to run the earlier pump, I'd sure make a new home for this one!
Let me know if you want to part with it.

[DRP67207]

Thanks for the info, that makes sense.  I'm going to stick with running this pump for the immediate future, seems to be doing well, so no reason to change.