Sender: <marv@lancaironline.net> (Marvin Kaye)
To: flyrotary
Date: Wed, 12 Mar 2003 21:08:48 -0500
Message-ID: <redirect-2051041@logan.com>
From: "Tommy James" <twjames@healed.org>
Subject: Injector Saga
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Hi Guys,
I had a real breakthrough today after several weeks of struggle.  The
culprit was my own confusion, lack of experience and one broken wire.
Also, many thanks to Ed and Tracy for their patient counsel and wisdom.. Of
course, all of you guys out there are a great help to me too.  In deed I
could not have built this Glastar which is almost ready for flight without
the help of friends on the Glastar list and the Fly-Rotary list.   Follow
this bloody trail with me as their may be something to learn from my errors.

1.	Beginning to run the engine in pre-flight setup and programming.  The
engine is running but very rough and will not idle down much below 1900
rpm…EGT’s running 300-400 degrees apart.  Peak rpm tried was 4300 with
plenty of throttle left.
2.	I started to think I had an injector problem, either not functioning at
all or at least out of balance on one rotor.  I had not installed the
injector cutout switches recommended in the EC2 instructions by Tracy. (
still have not put them in, but I will.)
3.	I put an email out to the group stating the problem with the Denso-2010
460cc injectors.
4.	Somewhere along the line, I got my wires crossed and focused on the
Denso-1350 460cc. Injectors that I also own but that are not used in the
plane.
Rusty posted this list this list:

Mazda RX-7(Gen 1 and 2) Fuel injector identification guide

Year | type | impedance | plug style | plug notch position | flow rating |
color | part number
------------------------------------------------------------------------

84-85 | 13B NT | low | square | center | 680cc | orange | 195500-0900
86-87 | 13B NT | low | square | center | 460cc | red | 195500-1350
86-87 | 13B T | low | square | center | 550cc | tan | 195500-1370
88 | 13B NT | high | square | offset | 460cc | purple | 195500-1350
88 | 13b T | high | square | offset | 550cc | purple | 195500-1370
89-91 | 13B NT | high | oval | center | 460cc | red | 195500-2010
89-91 | 13B T | high | oval | center | 550cc | purple | 195500-2020

5.	The 1350’s are low (2-3ohm) impedance. The 2010’s are higher at
12-16ohms.  Remember, I’m confused but unaware on my confusion..Duh?
6.	My mulitmeter is giving me strange readings.  That meter only had 10x and
1Kx scales.  This meter is an $8 Radio Shack wonder.
7.	My conclusion, again based on erroneous information, is that I have been
running low impedance injectors without the required 5ohm25watt resistors.
With the patient helpers advice I begin to get on the right course of
action.
8.	Enter DigiKey to the rescue.  I now have 5 resistors (one for screw ups)
and decide that this Meter has gone North and I must invest in a ‘real’
multimeter with the correct scale.  WalMart to the rescue.. Did you all know
they offer a quality digital meter for $18..?
9.	Now I have $30 worth of resistors and a new $18 meter..  Off to the
hangar.  I tested the meter against other injectors and resistors of known
value, so with confidence I put the meter on the installed injector and
those little hummers all measure in at 13.9 ohms…  That three of the four
measure that is.  The other injector is tucked away under a hose and more
difficult to reach.  Wonder of wonders.  I thought I had made a serious
mistake, but there was not mistake at all!!!  What a good boy!
10.	As I sat and pondered the stupidity of it all, I got the idea that I
should measure the last injector, because a difference in impedance my
reveal a faulty injector.  I pulled the clip off and that injector measured
13.9 ohms as well.  But the pay off came when I began to put the electrical
clip on and discovered that one of the wires to the clip had parted somehow.
No current to this injector for sure.., but when did it happen???  No one
knows for sure!
11.	Now, we have a bum clip and no replacement.  This little bits of brass
and plastic are very hard to find…(for me), and after trying to disassemble
this one I moved to other measures.
12.	I found that .110” wide crimp on AMP connectors, DigiKey #A0911-ND,
would go on the injector pins just fine, but I was a little concerned about
insulating in between the pins.  A 5/8” long piece of a nylon cable tie
wedged nicely into place.  Then the space around the pins was filled up with
liquid electrical tape.
13.	Now, if anyone can find fault with this arrangement, please let my know.
At least it will serve until I can find a replacement clip.
Dave Atkins has a supply of used ones.  Kathy, do you have a clip for the
89-91 Denso 2010?
14.	The engine then ran with much improvement until a thunderstorm moved in
to end the day.

The moral is that sometimes we think we have made mistakes and have not, but
the perseverance needed leads us to finding and fixing the real problem.
Does anyone need 5ohm resistors?
Thanks to All,
Tommy James<><