Boost Pin Question

[homerj1]

I was going to change the boost pin orientation  ( by turning the pin) on my 1.6td for a little more get up and go.  Everything I have searched shows the pin\diaphragm assembly removed from the pump. 

Do I need to physically remove the pin or can I just turn the pin\diaphragm assembly while it is still in the pump. And if so, how far to I turn it counter-clockwise?

Travis has a pic\post where he has it turned about 180 deg.

running k03, homemade dp and 2.25 inch exhaust - also have an egt gauge. Also the fuel screw has been turned up.

[carrizog60]

pull all the thing out and rotate.install.

[libbydiesel]

You can rotate it without turning it but bear in mind that the 'washer' with the dot on it can be rotated on the boost pin and so without pulling the pin out and looking at the ramp, there is no way to know what the relationship is between the dot and the ramp.

[homerj1]

Thanks,  So just pull it out turn it and then back in?

No tricks to getting the pin out or back in?

And any suggestions to how much I rotate it?

[libbydiesel]

Sometimes if the boost pin can get hung up on the pin that rides on it.  When that happens I clamp vice grips onto the nut and give a good yank that way.  How much you rotate it and which direction depends on what you are trying to accomplish.

[Trips_B]

forget turning it, take it out and grind a new more  aggressive slope 

[libbydiesel]

You could to that, but only if you want to destroy the functionality of it.     If you just want to smoke, then turn up the max fuel.  It's easier than ruining the boost pin.  Or better yet, just run a turned up non-turbo pump and sell the turbo pump to someone who actually wants a well-tuned fueling curve.  The boost pin is a variable ramp for very good reason and any grinding on it will destroy it, not make it better.

[vanbcguy]

I've generally been able to get the boost pin out without being too aggressive with it.  Usually if it hangs up I can get it out by turning it around a few times and wiggling without needing to put a ton of force on it.  I've never had to use tools on it personally.

Don't mess with the accelerator lever while the boost pin is out - the 'feeler' pin will pop out and block the hole otherwise.  If you do that you can push it back in with a small screwdriver but there's no reason to have to do that in the first place.

Remember there is a seal on that 'feeler' pin that can be damaged.  It is the most difficult seal to replace in the entire pump, so I try to disturb it as little as possible when messing with the boost pin.

In terms of adjustment, you can remove the white plastic collar on the top of the boost pin if it hasn't already been removed.  It prevents the boost pin from moving to its full power position.  It is part of the LDA tuning done by the factory, but it assumes you want stock power and boost levels.  Overall adjustment-wise I try to get the car to run smoke free without the LDA connected and then set it up to go as fast as possible with acceptable smoke while the LDA is plugged in.  There's basically 4 adjustments, not including swapping out parts:

- Total boost pin travel (the white collar)
- Boost pin ramp (what you change by rotating the boost pin)
- Initial boost pin position (the nut/torx screw on the top of the LDA housing - not there on AAZ pumps)
- Spring pre-load (the 'star wheel' that the boost pin spring sits on - not there on AAZ pumps either I believe)

[homerj1]

Thanks for the clarity and all the help! 

[libbydiesel]

The top bolt is somewhat redundant as any effect of changing it can be accomplished by adjusting star wheel, max fuel and idle.    On pumps that have the bolt I just set it so it so that it is up enough to not contact the boost pin so that I have maximum pin travel. 

Here's a trick to make LDA adjustment easier.  If you remove the rubber boot from the atmospheric bleed fitting and then remove the fitting, you can run a screwdriver in through the hole and have direct access to adjusting the star wheel without removing the lid and boost pin.  That makes fine-tuning the spring pre-load very easy.

[vanbcguy]

Here's a trick to make LDA adjustment easier.  If you remove the rubber boot from the atmospheric bleed fitting and then remove the fitting, you can run a screwdriver in through the hole and have direct access to adjusting the star wheel without removing the lid and boost pin.  That makes fine-tuning the spring pre-load very easy.

Brilliant...

[carrizog60]

on stock form the boost pin doesnt allow full travel,i have grinded mine and i still can avoid smoke on normal use,despite a full turned up 9mm pump.
its harder to do,but it can be done and that way i know for sure that the boost pin is allowing full travel.

[shorttimer]

Please make this a STICKY !