anybody ever try a lighter (easier to compress) spring under the lda diaphragm?
if so how was it?
i think i nam going to try it, but i am still waiting for other parts for the car.

i just took the top off of another pump i had, came off of a 89 1.6na with altitude compensator. the spring in there is much softer. my thought is the turbo would posably spool faster once it has started to build pressure, because it would be adding more fuel sooner due to the softer spring. just a thought?

by the way how do you upload and post pics here?
thanks

  imageshack hosts pics for free, you can link them to any web site you want, works great for me.

PS - pins of the VE pump altitude compensators I have looked at were not interchangeable with a LDA pin.  Was the one you looked at interchangeable?

The main difference in the ones I've looked at were, there was a big metal bellows in the top of the housing, and since that contracted when atmospheric pressure increased, and expanded when atmospheric pressure decreased, it moved the pin down when max fueling needed to be restricted more, and up when max fueling could be increased.  This is the opposite of an LDA function where downward movement of the pin means allow more fuel.

But maybe the atmospheric compensator you looked at was a different design?  The one I looked at was found in a VE pump but it wasn't from a VW (it was from a mitsubishi pickup truck, or some other mid-80's truck, I think.)  I do have it sitting in my garage, so can take another close look at it and pictures, etc if needbe.

PS - Thanks for the info on the boost pin numbers.  I added that info into the thread where we are collecting that data for comparison, here:
http://www.vwdiesel.net/phpBB/viewtopic.php?p=8179
It is interesting to note that someone else has found a different boost pin number in an '86 Jetta.

.I believe that the 89 hyd na motors also come with piston jets??..Idea . if so it looks to me as though a tricky guy could build him self a td motor w a intake man and turbo setup.

I have been told that all 1.6na don't have piston jets, but if you find out something different make sure you tell us all.  My car was manufactured 01/91(When ecodiesel production started), must be one of the last dreadful na models made.  Talk about luck huh?  Sorry for going a little off topic here, been stuck in the slow lane too long.

Nick

i have come across 2 that were na and had oil sprayers. they were automatic trans, one was a 91 and the other 92

some of my work in progress. the same dial indicator i use to set the ip timing threads into the hole in top of the lda. that and a pressure guage and pressure regulator alows me to set how much fueling ant certain psi, helps me decide choice of spring and starwheel ajustment and preeload.
i hate lots of smoke out the tail pipe for normal driving, but i do have an electric solinoid on a vacuume line going to the bottom side of the lda diaphragm. i flip a swithch and it pulles the diaphragm down with no boost and i can lug it and smoke out the "nice" people behind me. i also have a 2 stage custome boost cotroler for stock 10psi and power(22psi), i have plans that i drew up but sourcing the parts is hard unless you have "friends" that fix school busses, all the solinoids and hose and regulators are from various door and radiator shutter controlls on big school busses :lol:  whadda i know. it fell of the bus when i was driving behind it

I see you got the imageshack account set up. .

yup thanks for pointing me in the right direction



 .[/quote]  Your smoke on demand set-up sounds like it could be fun for tailgaters.[/quote]

oooh yea. thats why i have it. the car in the pics is going to be my autocrosser

its a 83 gtd. the head is on my bench awaiting the 3 angle valve job and a port (to a D port tdi manifold) and polish. i still have not decided what turbo to use but i am thinking  ecodiesel turbo, with my custom mitsubishi air to h2o intercooler.  i want as much powerband as possable for the track.
the autoX events i go to are usually small, but they get a kick out of a diesel cleaning up the track. time will tell the winning combo, but it will be fun :lol: in my pocket rocket.

That's a great idea to measure the displacement of the LDA device using a dial indicator set up like that, with a known amount of pressure... and really the threads are same as in the injection pump timing measurement hole?  Amazing, and you're the first I know to have thought of it.



In the past I've measured LDA cone setup by installing it, running it a few days, and observing the "scratchings" made on the control cone from the feeler needle... but using the dial indicator seems more reliable and quicker.

yup same threads, and i use a litthe grease around where the dial indicator fits into the pump adapter.  i measured the length of the ramp on the cone and compare it with the reading on the dial to make sure i am getting the full travel

So another GTD autocrosser... sweet!    I also love making people say "wow! That's a diesel?  I never knew a diesel could go THAT FAST!"  Beware that a ported head and turbo swap would put you into pretty tough classing category under SCCA rules, which is what is used for the most competitive national level.  I'll bet you could do well with it and have plenty of fun with it locally, though.  Does your local club use SCCA classes or their own?

using a ecodiesel turbo is still stock, there are no other vw's at any of the events i go to, and i was realy not going to tell them what i did.  thats why i want smoke to a minimum. the rule class book also does not show a gtd as an option, so they said i would go under a turbo diesel, "G Stock" but if i put the intercooler on it will get me to a "prepared cless"  the reason why i have no thought of telling them what i did to the car is, last year when i raced my stock 91 peugeot 405 mi16 "H Stock"and cleaned up track, i got disqualified for cheating, but i never cheated. i won every event in my class and in the next class up fare and square. maybee they dont like french cars, well they banned that car from the track. sore loosers. it even had the stock exhaust and intake with paper filter and posi from the factory and original clutch with 80,000 miles on it.   so since i cant race the Peugeot, the old "rabbit" is going to be next to clean it up, but it will take time and experimentation with what combo of tires/pressure and shocks and springs. schirocco sway bar and springs are next.   oh yea, the first time i raced the peugeot, they laughed in my face and said "you wanna what withe the family 4 door" i told them "just wait n see"   well i took second place, with h rated tires, real junk.
 :lol:   the rabbit will be a harder challenge, it does not handle nearly as well as the peugeot.