Injector Pump Question

[VelocityConservation]

Noobie question I am sure but I have not been able to find anything on this yet...

I have a 1990 1.6L N/A Jetta, it came stock with this injector pump installed.  It has the Altitude compensator stuff on it.  Could some one please tell me what the piece that the arrow does.  A little explanation of how the Altitude LDA differs in operation from the TD (I know it limits the fuel rather than enhancing it :wink: ) would be greatly appreciated as well.



The second question is: What does the adjustment "linkage" (arrow) do?



Thanks Everyone.

For the long explanation.  I have installed a new pump without the Altitude compensation.  The car runs very good, except the governor seems to come in much sooner.  The new (rebuilt) pump had "nooses" around the max fuel, residual fuel (not sure if this is the correct term) and the linkage in the second photo.  I want to make sure that I have done all the other things I can before I do the Gov-mod.

[91turboeco]

the ''linkage'' is a fuel screw loosen the lock nut and turn it in it feed more fuel to the motor, but you said n/a so its not go to help much if any.

as for thr first question can help you

[moosiah]

Hi the "solinoid" looking thing is a injection advance  control device., it cuts off the advance below X engine rpm... wire it to the fuel shutoff terminal or figure out how to remove it ........  in the other pic the arrow pionts at the max fuel screw, the linkage is hooked to the coldstart advance lever and the idle stop.kinda like a choke on a gasser, pull the leveron a real cold morning, get a couple 'a degrees advance and a bump in idle.......   it works by pulling a vacume under the dia in the aneriod , then bleeding air in to back it off to limit fuel at altitude... someone on this list switched the hoses and used it as a regular enrichment boost type pump, can't remeber now who it was ...... the good news is that your block has the oil piston cooling jets and could be made a turbo.. ...  or a NA that would last a real long time............
PS I've got one of these too  on a 89 engine.......

[Northboundtrain]

...... the good news is that your block has the oil piston cooling jets and could be made a turbo.. ...  or a NA that would last a real long time.............

When did VW start putting oil squirters into NA blocks?  Does any NA engine that came with the the altitude compensation device on the pump for sure have oil squirters.  I have a '91 NA engine with this type of pump, and it would be great if I could convert it to TD some day.

Thanks

[bryanbryan89x]

injection advance  control device., it cuts off the advance below X engine rpm... wire it to the fuel shutoff terminal or figure out how to remove it

Hi, I am going to be putting one of these pumps in my 81na soon.  how/why do you need to remove this thing??

Thanks, Bryan

[wyldman]

Is is strictly for emissions.It will hurt power and economy.

[VelocityConservation]

My ETKA part CD does not show oil squirters for ME (N/A) engines.  Although I have not had the pan off of this engine I do not think it has the stuff to make an easy transition to a TD, and I do wish it did.

Note: I now have had the pan off of this motor.  Definitely no oil squirters in this ME.

[VWDieselDoc]

Hmmm... there seems to be a little bit of confusion as to how this thing works.

First, the solenoid operates totally independent of engine RPM.  It operates based solely on barometric pressure, or altitude.

The Anerioid on top of the pump operates on vacuum.  Notice the vacuum line is connected to the lower part of the diaphragm.  It pulls the diaphragm DOWN, just as the pressure from a turbo engine pushes the diaphragm down under boost conditions.  In short, it adds more fuel.  There's a valve mounted next to the fuel filter.  This valve bleeds off vacuum at high altitudes, but remains closed at lower altitudes.  When the valve is closed, The vacuum pump creates vacuum in the line, which in turn pulls the diaphragm down.  The pump delivers its normal amount of fuel.  At high altitudes, the valve opens and the vacuum is bled off.  No vacuum to pull the diaphragm down results in less fuel delivery.  To disable it, you need to remove the "tee" from the line and connect the line from the vacuum pump directly to the aneriod, thus taking the altitude valve completely out of the loop.  Also disconnect the electrical connection to the solenoid so it can not be energized.