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Engine Specific Info and Questions => IDI Engine => Topic started by: iheartbeets on January 19, 2013, 05:21:10 pm

Title: Disconnecting altitude compensation
Post by: iheartbeets on January 19, 2013, 05:21:10 pm
I searched and see that this has been somewhat covered but here goes:
Car was NA with LDA. I now have an Eco engine that I rebuilt and installed. Giles converted the pump to true turbo. I want to clean up the engine bay. I disconnected the altitude compensation on the passenger wheel well and car proceeded to run like poo. Is there a way to delete that whole mess? 

Thanks!
Title: Re: Disconnecting altitude compensation
Post by: theman53 on January 19, 2013, 05:41:06 pm
get rid of the alt compensation and hook your new TD pump up to manifold boost presure.
Title: Re: Disconnecting altitude compensation
Post by: iheartbeets on January 19, 2013, 06:47:01 pm
The vacuum lines are fine. It's the electrical part that's giving me trouble. I want to eliminate the switch that's mounted to the fuel filter. If I simply unhook it, it causes rough idle. Maybe it's possible just to jumper it?
Title: Re: Disconnecting altitude compensation
Post by: TylerDurden on January 19, 2013, 08:35:16 pm
Does the IP still have the electric valve on the side? (The one fitted to the timing-piston cover)
Title: Re: Disconnecting altitude compensation
Post by: iheartbeets on January 21, 2013, 08:21:51 am
Yes it does. When Giles did the pump, he just modified the aneroid to respond to boost pressure. It still has the valve on the side and it has power to it.
Title: Re: Disconnecting altitude compensation
Post by: TylerDurden on January 21, 2013, 02:16:28 pm
If it runs like poo without 12v at the electric valve on the IP, I'd just split 12V from the fuel cutoff line over to the valve.

I can't remember exactly what the valve controls, but it acts the opposite of a fuel cutoff solenoid: it pushes out with 12v applied.

I went the other way: I put a 91 eco IP on my 89 NA, so I could do the turbo conversion to the ADA pump on a turbo engine (yet to be rebuilt).
Title: Re: Disconnecting altitude compensation
Post by: TylerDurden on January 23, 2013, 06:16:02 pm
Well, for grins I put my 89 NA IP with the ADA on my 85TD. I switched the ports on the aneroid chamber to mimic the TD setup.

I really can't tell the difference between the two pumps.

The electric valve seems to make no difference with 12v or none.  ???



Ok, not just for grins... my TD pump was leaking like a sieve from the cold snap. I plan to take it to the shop and have a new bushing installed while it's out of the car.
Title: Re: Disconnecting altitude compensation
Post by: R.O.R-2.0 on January 24, 2013, 08:00:01 pm
Well, for grins I put my 89 NA IP with the ADA on my 85TD. I switched the ports on the aneroid chamber to mimic the TD setup.

I really can't tell the difference between the two pumps.

The electric valve seems to make no difference with 12v or none.  ???



Ok, not just for grins... my TD pump was leaking like a sieve from the cold snap. I plan to take it to the shop and have a new bushing installed while it's out of the car.

i believe that you have to change more than just where the boost is supplied to the aneroid..
Title: Re: Disconnecting altitude compensation
Post by: 8v-of-fury on January 24, 2013, 09:36:04 pm
Said he couldn't see a difference between the pumps lol.
Title: Re: Disconnecting altitude compensation
Post by: srgtlord on January 25, 2013, 05:32:38 am
The late NA pumps look identical to turbo pumps
Title: Re: Disconnecting altitude compensation
Post by: TylerDurden on January 25, 2013, 05:45:25 am
The main external difference is the electric valve that has a tube leading to the cover.

(Disregard the annotation.)
(https://lh4.googleusercontent.com/-6mZLbgaBTWg/UQKLzoSfB5I/AAAAAAAAA7o/YJAk8C5TCgw/s800/IPmarks.JPG)

The Bosch docs I have don't indicate the function, but it may be a way to vary pressure on the side of the timing piston with the springs or a way to control pressure in the governor shaft.
Title: Re: Disconnecting altitude compensation
Post by: srgtlord on January 25, 2013, 09:23:25 am
I have 2 NA pumps with the tube running to the cover just like the one pictured. Does that mean that vw got lazy and just put the remaining turbo pumps on N/A cars in the early 90's ?
Title: Re: Disconnecting altitude compensation
Post by: TylerDurden on January 25, 2013, 09:35:24 am
There is also a version with no aneroid that has a tube going to the pressure regulator.

(https://lh5.googleusercontent.com/-i_yJD8GELdI/UQLBuEG2SII/AAAAAAAAA74/uEeYFLklKqA/s800/waxmotorKSB.jpg)

My understanding is that version is a hydraulic KSB (cold start), as it has no CS lever on the opposite side of the timing piston.
Title: Re: Disconnecting altitude compensation
Post by: bajacalal on January 25, 2013, 08:02:46 pm
It looks like the KSB (no idea what that stands for) I have seen on other engines including Cummins and Volvo, and yes, it's function is that it advances the timing when the temperature sensor reads below a certain temperature. It think it would be fairly easy to manually control the KSB circuit.
Title: Re: Disconnecting altitude compensation
Post by: 745 turbogreasel on January 26, 2013, 01:03:34 am
The Volvo one is different, and is a load compensating  timing control, depowered above 6000 feet.
(http://i222.photobucket.com/albums/dd74/marthin_f/DSCN3028.jpg)