Convert NA pump w/ altitude correction to TD pump?

[TimpanogosSlim]

Just back from the junk yard. One of the goodies i brought home was an IP i had thought was a turbo pump.

Numbers on the pump:

0 460 494 200
R 254 BS 4010
068 130 110 N

Everything I've found with google indicates that what i have here is not a turbo pump - it's an NA pump with an aneroid for altitude correction.

Configuration is like this (not my picture):



Ideally I'd like to re-seal this pump myself, perform the governor mod, install a higher performance cam disk, and do whatever needs to be done to use it as a TD pump on my 1.6TD.

What parts do i need (aside from seal kit) and where do i get them? I do know a good bosch dealer but he is no VW specialist.

[mk2drtydiesel]

I have a td pump on my n/a. The alt compernsotr bolt is open... On a normal td it goes to intake side reads boost pressure on a n/a there is none on my injection pump I just have a open hole there ,no liner reading atmospheric pressure. It doesn't work seeing no boost pressure, can conpensate by playing with fuel screws.

[mk2drtydiesel]

I would call Giles see what he could do google search you'll find him

[TimpanogosSlim]

Yeah i know about giles. I was pretty sure i saw some discussion of how to convert the LDA from atmospheric to turbo but *Shrug*

I should also get the part number off of the LDA.

[TylerDurden]

The aneroid in/out fittings just need to be swapped. Done.

[jlpst94]

Assuming that it doesn't need rebuilt....... Yes you just swap the in and out.
Also,  Giles can take care of this and make your pump perform.   I just had him do this swap and rebuild and it was worth every penny.   I had all of the DIY mods done to my previous pump, turbo, downpipe, etc... and  my 1.6 did run pretty well.     But.... Not even close to what it runs after letting Giles rebuild the pump and matching the boost to what he recommended.     Couldn't be happier.   We have an A3 TDI,  but for daily driving I'd much rather jump in my 91 jetta

[TimpanogosSlim]

I'm well aware of what Giles can do for me. But i am not at a stage of my build or in a financial position to go all out and drop a couple grand on a super pump and a holset turbo.

.:Sent by pneumatic tubes

[ToddA1]

The aneroid in/out fittings just need to be swapped. Done.

You sure that's it?  I'd figure everyone would swap the fittings and ask more for their standard pump. I could have sworn I've read there was more to it.

-Todd

[TylerDurden]

I'm running one on my '86 1.6 without issues.

[TimpanogosSlim]

I ought to take some good pictures of this pump and post them. How hard or fraught with peril is it to take the lid off and look at the lda pin? I have some watchmaking experience fwiw, but gear trains are more straightforward than pumps.

.:Sent by pneumatic tubes

[theman53]

the LDA pin is easily gotten by taking the 4 screws off the top and lifting the rubber diaphragm. You do not need to take the top of the pump off just the flat piece on the very top. Nothing too hurtful in there. Check the make your 1.6 td a faster car thread and see the description.

[TimpanogosSlim]

Thanks. some day soon I'll give it a whirl.

[jmaddocks]

I did this last fall.  On mine ('89 NA), the aneroid in and out have different size threads, so I couldn't just swap them.  I ended up replacing the upper fitting with a brass threaded barb connected to a manifold pressure signal and letting the bottom one vent to the atmosphere.  I increased the spring preload with the star wheel and rotated the LDA pin for the greatest delta between on and off boost. 

Unfortunately, the aneroid spring in those pumps is really weak, so it starts increasing fueling way too early.  I thought about ordering a high performance spring for a cummins VE pump (google "cummins AFC spring") but didn't know whether it would fit.  The local diesel tuning place didn't have any either.  In the end, we've learned to simply modulate the throttle manually until boost starts building, which doesn't take very long.

[libbydiesel]

As mentioned, the IN/OUT for the aneroid are different thread sizes so the fittings do not just swap.  The fitting for the atmospheric side has a small filter to keep dust out of the aneroid.  I would not recommend leaving it just open.  The TD pump fittings will fit in the correct locations.  Also as mentioned, the spring is weak in the alt comp pump.  Also the boost pin is less aggressive than the TD version.  It will work with the boost to the correct side of the diaphragm and is a step up from a non-turbo pump but does not have the same range of on/off boost fueling that the TD pin and spring will give. 

[TimpanogosSlim]

fwiw, here's a picture of the configuration as pulled from the junkyard: