AAZ IP Q

[Big Daddy Roth]

What is the solenoid on the front of the pump for?

When should it have 12v to it? Throttle switch (on top of pump) open or closed?

[wdkingery]

Speaking of which, what were those little black buttons on an ME for anyway?

[steevz]

What is the solenoid on the front of the pump for?

When should it have 12v to it? Throttle switch (on top of pump) open or closed?

If you look at the post for "Make your 1.9 a faster car" in the faq. It has something to do with reducing emissions if I remember correctly.

[JamesT]

Mine doesn't seem to get power at any point.
There's no throttle switch on my pump.
I've been trying to figure this out. It doesn't get power cold not running, glowing, cold idle, cold revving, warm idling, warm revving, or warm not running. The only thing I haven't been able to test is with load on, and I don't know how the car would know, since it's an early mk3.

Do you have a spare AAZ pump in your stash somewhere? (working or otherwise?) I'd like to figure out exactly how all the internal ports work in the dynamic advance part. I think I'm going to hook it to a switch and see how it affects my EGT's once I start to get everything set up properly.

[Big Daddy Roth]

Mine doesn't seem to get power at any point.
There's no throttle switch on my pump.
I've been trying to figure this out. It doesn't get power cold not running, glowing, cold idle, cold revving, warm idling, warm revving, or warm not running. The only thing I haven't been able to test is with load on, and I don't know how the car would know, since it's an early mk3.

Do you have a spare AAZ pump in your stash somewhere? (working or otherwise?) I'd like to figure out exactly how all the internal ports work in the dynamic advance part. I think I'm going to hook it to a switch and see how it affects my EGT's once I start to get everything set up properly.

pm'd

[Big Daddy Roth]

Anyone?

[410]

The solenoid on the front of the pump blocks a port and increases internal pressure when energized.  This pressure increase advances the timing a little for better cold weather operation.  I would leave it disconnected as long as you have your cold start advance cable hooked up.  Also energizing this solenoid during normal operation advances the timing too much.

The micro switch on the throttle lever is normally closed in low throttle positions which puts power to a vacuum solenoid valve that puts vacuum to the other side of the wastegate.  This opens the wastegate sooner reducing boost.  I think it's main purpose is to reduce exhaust back pressure increasing efficiency but I prefer disconnecting the whole setup and let the turbo do its job.  The engine is more responsive when this system is disconnected.  You can try it by disconnecting the vacuum line that goes from the vacuum solenoid to the wastegate and take it for a spin.

[dieselweasel]

Mine doesn't seem to get power at any point.
There's no throttle switch on my pump.
I've been trying to figure this out. It doesn't get power cold not running, glowing, cold idle, cold revving, warm idling, warm revving, or warm not running. The only thing I haven't been able to test is with load on, and I don't know how the car would know, since it's an early mk3.

The solenoid in question will receive 12v+ when engine RPM exceeds 3000 IIRC.  This keeps timing retarded below 3000 rpm, reducing NOx emissions.  On my cars I have always hotwired 12v+ to this solenoid and really never noticed a large difference in power or economy. 

[CrazyAndy]

Mine doesn't seem to get power at any point.
There's no throttle switch on my pump.
I've been trying to figure this out. It doesn't get power cold not running, glowing, cold idle, cold revving, warm idling, warm revving, or warm not running. The only thing I haven't been able to test is with load on, and I don't know how the car would know, since it's an early mk3.

The solenoid in question will receive 12v+ when engine RPM exceeds 3000 IIRC.  This keeps timing retarded below 3000 rpm, reducing NOx emissions.  On my cars I have always hotwired 12v+ to this solenoid and really never noticed a large difference in power or economy. 

So if someone ran an AAZ in an earlier car like MK1 or 2 they'd need to have 12v to this all the time the engine is on?

[410]

Energizing this solenoid makes enough of a difference in timing that you can actually hear it.  I had it wired up to a switch so I could advance the timing a bit when the engine was cold. 

There is a bleed port on the governor shaft that gets blocked to increase timing under high load conditions.  If that solenoid is energized it completely eliminates this feature since the bleed port on the governor shaft dumps into the line this solenoid is on.

[dieselweasel]

Mine doesn't seem to get power at any point.
There's no throttle switch on my pump.
I've been trying to figure this out. It doesn't get power cold not running, glowing, cold idle, cold revving, warm idling, warm revving, or warm not running. The only thing I haven't been able to test is with load on, and I don't know how the car would know, since it's an early mk3.

The solenoid in question will receive 12v+ when engine RPM exceeds 3000 IIRC.  This keeps timing retarded below 3000 rpm, reducing NOx emissions.  On my cars I have always hotwired 12v+ to this solenoid and really never noticed a large difference in power or economy. 

So if someone ran an AAZ in an earlier car like MK1 or 2 they'd need to have 12v to this all the time the engine is on?

That would be ideal, yes.

[410]

Mine doesn't seem to get power at any point.
There's no throttle switch on my pump.
I've been trying to figure this out. It doesn't get power cold not running, glowing, cold idle, cold revving, warm idling, warm revving, or warm not running. The only thing I haven't been able to test is with load on, and I don't know how the car would know, since it's an early mk3.

The solenoid in question will receive 12v+ when engine RPM exceeds 3000 IIRC.  This keeps timing retarded below 3000 rpm, reducing NOx emissions.  On my cars I have always hotwired 12v+ to this solenoid and really never noticed a large difference in power or economy. 

So if someone ran an AAZ in an earlier car like MK1 or 2 they'd need to have 12v to this all the time the engine is on?

That would be ideal, yes.

I politely disagree.   But that's just my opinion.

[8v-of-fury]

That would be ideal, yes.

I politely disagree.   But that's just my opinion.

Begin discussion!

[vwnut84]

I had my solenoid hooked up to 12v and I also did not notice an increase/decrease in performance or economy. 

[hippiekiller]

On my cummins VE the solenoid in calles a ksb (*german for kold-start) and does what 410 states, usually controlled by a  thermo switch on the cylinder head on those engines....I have that one hooked up to a switch for less smoke when cold starting....my vw one I wired as per the sticky but have always doubted the method...my 2