hey,
how do I remove the govenor in my pump? I know yoou have to remove the spring and replace it with something solid but how do I actually access the spring.  does anyone have pics of this being done?
thanks fo the help

The place to start is by stuying this thread from our old forum.

That having been said, it is clear from your posts that you are not too familiar with these engines. If you go nuts and blow up your engines, may a pox be upon you! (That's old timey talk for, it's your own fault!)

I'm not going to say too much here, because I don't remember the exact numbers, and Giles is away on vacation till june 18th. But, I believe that the advance mechanism actually stops advancing at a significantly lower rpm that what you'd expect. There is a considerable gain to be had beyond this point by having the advance mechanism modified. Replacing/modifying the max speed govenor spring is only half the battle.
(but definitely far better than nothing)

Edit: let's try and research if a custom timing advance cover could improve the timing much.  If it might be helpful, I might be able to design and get a batch of them CNC machined but initial cost is high (It's at or above $100 and that cost doesn't seem to matter how many are made!) so the cost per unit goes down dramatically if we were to have a number of them made.  But I would have to be smart in the deisgn so I don't have 100 non-useful covers made up.   :?

At 1.17mm, the engine ran rougher, seemed to smoke more at part-load, sometimes backfired or reverse-fired or something awful like that when starting (no need to pull out the cold start knob - also I sure wouldn't recommend using spray ether with this much advance setup ever!)  I really didn't like that whole starting backfiring thing.  But, it did work OK like that for power (IE: it didn't hurt power anywhere running that much, but only helped slightly at highest rpm measured, 5750rpm.)  I actually drove to Topeka Kansas and raced at nationals in 2003 with my injection timing set at 1.17mm.  But now it's back to 1.00mm and it's much happier (I would have set to to 1.00 for nationals too but just left it at 1.17mm because I didn't have time to change it then.)

If you were to over-advance it beyond 1.17mm I'd be weay of loosing power somewhere in the usable power range.  When I was dyno testing I couldn't easily try anything above 1.17mm because that's all my pump would rotate without changing the timing belt over 1 tooth on the timing belt.  Dyno time was a little too precious to take the time to do that for me.  But I felt 1.17 was pretty far advanced enough and woulnd't gain much testing benefit testing higher values.

In other words, it doesn't make sense to optimize your entire rpm range of timing for just one specific, very high, and not very usable rpm.  But, it may have been useful to determine what rpm got helped from advancing the timing this much, if the results can be trusted which I am not 100% confident in, it might help us figure out what is happening with the timing advance mechanism.  If the dyno results can be trusted, I would conjecture that the 84 Jetta 1.6lTD stock pump is limiting timing advance somewhere between 5500-5750rpm, possibly a little lower but not likely by very much.

Oh by the way the timing advance mod I am talking about above would leave the timing unchanged until the stock timing advance piston ran out of travel.  It would just increase the travel that it had available.  I'm not sure if it's possible with just an external pump cover swap, or if more extensive internal pump modifications are required though.  It depends what exactly is limiting the travel of the timing advance piston, which I am not yet sure if it's just the cover itself or if it's something inside the pump.

A couple of thoughts in terms of cost. (assuming that Jake is right and this will work)

1. A spacer could be used, not a complete new cover. These could be made on a digital readout mill quite easily, especially if the diamond shape wasn't critical. As I mentioned in another post, I think the Dr. Diesel trimmed 3mm on his pump. Why not make 1mm spacers so there would be some tunability? Actually, as I think about this, it gets even easier. The holes are only for clearance so you could take a stack of 1mm shims and just drill three holes through them on a crappy drill press.

2. If the cover can be round instead of diamond shaped, they can be turned on a CNC lathe in about 75 seconds per part. You would still need to drill the bolt holes though unless the lathe had live tooling.

Dropout

Edit: let's try and research if a custom timing advance cover could improve the timing much.  If it might be helpful, I might be able to design and get a batch of them CNC machined but initial cost is high (It's at or above $100 and that cost doesn't seem to matter how many are made!) so the cost per unit goes down dramatically if we were to have a number of them made.  But I would have to be smart in the deisgn so I don't have 100 non-useful covers made up.   :?

That too, but I'm sure there was something with the advance mechanism. I tried the old site to check, but it's down.

Dropout

Dr Diesel has a small amount (less than 1 mm IIRC) shaved off the back end of his engine's injector pintals. This allows faster injection since when the injector opens less of the tip of the pintal is obstructing the injector hole. The modification is not related to timing, per se.

I have never seen a detailed explanation or write up of how either of these mods work.  Only teasers that they exist!  :?  And I have asked how they work but no one answers.

C'mon...  I share everything I know with you guys.  Is that too much to ask in return?