DIY injector cleaning

[Christopher J. Bruno]

> >  Andris,
> > i guess the answer was NO there isnt a GOOD way for the DIY to clean injectors other than a additive in
> > the tank.
> >
> 
> > Jimm L.
> > the injector " guru"
> 
>   Well, I'd like an expert's opinion, but we've been using a machine which circulates a solution of
> gasoline and cleaner through the injectorsand fuel rails while they are on the vehicle.  It's called
> Motorvac, and it's made by Sun Equipment.  The point of the machine is to remove carbon from the engine but
> I have seen visible improvements in GM TBI spray patterns, and Ford port setups respond really well.
> 
> The cleaning solution is so similar to GM's Top Engine Cleaner that we've used the GM stuff pretty
> interchangeably.  Shouldn't be too hard to rig up a tank, pump, supply and return lines and let this stuff
> circulate for a while.  If you could fire the injector(s) the solution could flow through them for a while,
> and after that I'd replace the filters and O rings.
>

Hello gang,
	First off I would like to say thanks for the incredible
amount of information this list has.  The discussions have re-
sparked my interest in learning enough EE to construct my own
circuits to drive an FI system.  I would also be very interested
in the proper connections to the ALDL to connect to an RS-232 port.
I haven't written much serial interface code but I'm sure I could
learn so if anybody has this data I would gladly research the
software side to try to supply a scanning code that would be free
for all of us.  In any case I have a little something to offer
on the fuel injector cleaning.  
	I haven't yet completely disassembled my newly acquired
TPI setup which is strewn about on my basement floor as a trace
all the wires, BUT I was working on my SHO with a friend one day
when he showed me a very interesting way to clean the injectors
while in the car. We took an air compressor line water filter with
the filter removed, and filled it with straight fuel injector
cleaner (like what you would buy at K-mart).  We then tripped the
inertia switch on the fuel pump to shut off fuel flow and connected
one end of the 'water filter' to the schraeder valve on the fuel
rail.  The other end of the 'water filter' was connected to a simple
air compressor regulator which we regulated to around 35 psi and then
turned on the air.  We started the car and ran the straight fuel
injector cleaner through the injectors.  
	Apparently, this is in essence the same way garages and 
dealerships use to clean the injectors while on the car (using
perhaps slightly less kludged equipment).  Although it doesn't
account for backflushing or screen replacement, it did make
an excellent difference in the idling and off-idle performance
of my car.  Not so much in power but in smoothness.  All done with
probably $15 worth of hardware (providing you already have an
air compressor).
	Well, this is my mechanical advice (coming from an ME),
but if anybody out there (I see Bruce Bowler adds a lot in this
category) can offer tips and ideas on circuit design (perhaps
more catered to non EE's) I know I would enjoy it.  BTW, if anybody
has any books they can recommend for me to learn about the different
chips (i.e. what a 555 timer is) I would appreciate it.

Thanks!

Chris Bruno
Mechanical Engineer
Teradyne
321 Harrison Ave. H63
Boston, MA 02118
bruno at icd.teradyne.com