TD IP vs. NA with Altitude Compensator

[VelocityConservation]

What are the differences between these two IP's?

I am saving my coins for a Giles IP rebuild.  I have a NA pump with the altitude compensator.  Will Giles be able to build a good TD pump out of it as a core? or am I better off buying a "real" TD pump core?

Thanks,

VelocityConservation

[jtanguay]

he should be able to make that pump act like a TD pump.  its basically a fuel enrichment device, but reduces the fuel at higher altitude.

[spencebm]

I have one of these too but I am not sending it to giles, is it worth it to try and convert the Altitude Aneroid to see boost and add fuel or would it be better if i spent the money on a real turbo pump?

[Vincent Waldon]

You know how friendly we Canadians are... if you call him I bet he'll tell you exactly what mods are possible with the altitude-correction version of the pump.

[Ziptar]

From what I read TD IP LDA and a NA Altitude Compensator are no different. It's the plumbing that is different.

While an LDA relies on boost vacuum to control fueling, the ATM works just the opposite. Vacuum moves pin in the opposite direction. So basically swapping the lines and fittings on an ATM and connecting a vacuum line from the top fitting on the ATM to the intake manifold gives you an LDA.

From what I have read internally they are identical with the exception of the spring, ATM spring is softer and kicks in sooner and leads to earlier spooling, other than that the boost pin and internals are identical.

http://www.vwdiesel.net/phpBB/viewtopic.php?t=5710

[cowboybootlegger]

VelocityConservation, please remove the four screws on the top of the aneroid and pull out the aneroid pin/diaphragm on the altitude compensation pump.  Snap a picture of it along with a picture of the internals of the aneroid and post them here.  Then put it back together.  BTW those four flathead screws can be tight.  I often use a screwdriver that accepts a flathead bit and a 1/4" six point wrench around the bit for leverage.  Press down on the screwdriver handle hard while turning with the wrench.

Andrew

Or use an impact type screwdriver if they're too tight for Andrew's trick, that seems to work well on steel screws in aluminum housings, i've used it a ton on motorcycle transmission casings and such.  They're fairly readily available, for cheap.  

[CoolAirVw]

Or use an impact type screwdriver if they're too tight for Andrew's trick,

Hey you!  Thats what I was gonna say!

[jimfoo]

Haven't tried taking a phillips out of a motorcycle have you?  :lol:

[VelocityConservation]

Well back to the question.

http://i96.photobucket.com/albums/l193/PhlatOut_2006/IPAneroid003.jpg
http://i96.photobucket.com/albums/l193/PhlatOut_2006/IPAneroid004.jpg
http://i96.photobucket.com/albums/l193/PhlatOut_2006/IPAneroid006.jpg

There is a needle that rides on the aneroid pin down there.  My camera can't focus that macro.  I will try to get a photo straight down tomorrow.

Well the 4 screws came out with just some elbow grease (and one grunt), no need for the Libbybapa trick or my impact tool.

VelocityConservation

[jtanguay]

just as i thought... just hook up a boost line to it and adjust the starwheel. its basically a turbo pump.  looks like a 1.6TD boost pin too!

[zukgod1]

Yip, I changed my altitude LDA pump over for boost referance...

good to go...

[ScottyTD]

im bringing this back from the dead.  so from this thread the NA pumps with an  altitude compensator is exactly the same as a TD pump?   and does any one have the pics to put up again? 

[Cynical 1]

i'm inteested too, as the pics seem to be down...

any how-to pics for this?

what parts to swap/change?

[ScottyTD]

Well as far as I can tell the altitude compensator has a LDA but it connects to exactly that the atmosphere.   I think if you just connect a tube from the top of the LDA to the turbo it should act the same?     There is also a wierd switch on the front side of the pump with  a thin hardline that goes right above the gear ?  I will try to get pics

[ScottyTD]

 that helps alot!  so we bought a 1.6na motor and got an injection pump thats pretty much a TD...  Very Nice