Re: [T3] upgrades to stock-FI motor?

[Jim Adney <jadney@vwtype3.org>]

On 20 Sep 2006 at 11:12, Constantino Tobio wrote:
  
> I actually made a leak tester for my injectors. Essentially I made a
> "tank" made of 4" PVC pipe (has a volume of maybe 20 oz), a 5/16 hose
> barb, a pressure gauge, and a quick disconnect for my compressor.

I've actually got an alum can for the injectors to spray into and a lucite lid 
to hold a pair of injectors in the usual geometry. I just have to add a pump, 
filter, pressure regulator, some support framework, and plumbing.

> I fill up the "tank" about halfway with kerosene and I put the injector
> on a hose. I pressurize the "system" to 30 lbs by setting the compressor
> regulator to this. I leave the injector in a mason jar and see if it
> leaks after a few hours.

That seems like a pretty reasonable way to do a simple leak test. A leak that 
takes more than 15 minutes to show up is probably not significant enough to 
matter.

> As for exercising them. I imagine you could somehow rig an ecu, feed it
> power and pressurized fluid to the injectors, and have something that
> would oscillate the trigger contacts circuits. Am I on the right track
> here? Or would it be simpler to oscillate an electrical signal at the
> right voltage for the injectors while delivering pressurized liquid?
> Someone with knowledge of simple electrical circuits could probably
> design this easily and make it in a breadboard.

I've got an exercise circuit on a breadboard, but I need to resurrect it and 
make a permanent version. It's adjustable in pulse frequency and pulse width. 
Once done, I need to mount it to the same framework and set it up to get power 
from the same 12 V source as the pump.

-- 
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

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