Installing the Jacobs Omni Pak Ignition
From: "Marc L. Summers-SysAdmin" <marcs@tdd.hbo.nec.com>
Subject: Detailed Instructions For Jacobs Ign.
To: uunet!validgh.com!mr2-interest@uunet.uu.net
Date: Mon, 15 May 1995 5:10:27 PDT
Mon May 15 05:07:32 PDT 1995
Detailed Instructions on how to install the
Jacobs Omni Pak Ignition system on a
1993 MR2 Turbo
===============================================================================
WARNING DISCLAIMER: Any and all work you do on your car is your responsibility
You under take this task at YOUR OWN RISK, as you do with
anything that YOU do to your car.
===============================================================================
WARNING:
This installation makes the assumption that the HKS super power
flow air filter or something similar has been already installed
such that the stock filter air box has been removed and
that the rubber bushings and mounting screws were saved from
the air box bottom.
===============================================================================
WARNING: All of the measurements, wire lengths, and any other measurements
should be considered APPROXIMATIONS. To follow my specific wire
lengths to the letter would make the ASSUMPTION that the product
is manufactured all the same, which MAY NOT be the case.
Always measure your own specific application before cutting ANY
wires to length. You may want to do it differently.
===============================================================================
CAUTION: You must make your own decision as far as what specific safety
precautions you want to adhere to. I can tell you what I did, but
that may or may not be what you consider prudent or safe.
You must decide what level of safety you consider appropriate.
As always when working with or on any machinery certain basic
COMMON SENSE safety precautions are prudent.
In this particular installation I did NOT disconnect the battery.
But by all means ensure that the key is OFF.
===============================================================================
NOTE: PLEASE read through the instructions at least once before attempting to
actually do the installation.
===============================================================================
NOTE: I have proof read this text, but I am only human, I do make
mistakes, and could have possibly left out some key piece of info.
If you find such a mistake please notify me so that I can get it
corrected.
===============================================================================
TOOLS USED:
Torque wrench that can go to at least 25 foot pounds
14 (inch), 1/4 inch drive extension
1/4 to 3/8 drive adapter
10 (inch) 3/8 drive extension
3/8 drive ratchet
1/4 drive ratchet
5/8 spark plug socket (3/8 drive)
small pair of wire cutters
10 mm socket 1/4 drive
6 (inch) 1/4 drive extension
10 mm open end/ box end wrench
#2 phillips screw driver 6 (inches) long
12 mm socket 1/4 or 3/8 drive
25 watt soldering iron
60/40 electronic (resin core) solder
dial calipers
spark plug gapping tool that goes to at least .031
small tube of lock tite
small tube of anti sieze
duct tape
electrical tape
two 7 (inch) tie wraps
one 4 (inch) tie wrap (if you have to mod the universal trigger)
channel lock, or standard set of slip joint pliers
hack saw
pair of scissors
two electrical terminals, with 1/4 center hole for #18 or #20 wire
two 1/4 center hole star washers
electrical terminal crimps, or just use the pliers
air compressor with 100 psi capability
shrink tube heat gun, (much hotter than a hair drier or use a
cigarette lighter
wesleys Black Magic
4 large bath towels
4 small rags
===============================================================================
PARTS PURCHASED:
Jacobs Omni Pak, part number #380888
When ordering the Jacobs omni pak you MUST specify exactly
what you want for the Jacobs to distributor wire, and the
Jacobs Universal trigger assembly.
To order specify the following for the (jacobs to distributor wire)
#13 terminal and boot on the distributor end.
And 13 inch length.
For the Universal trigger assembly, specify #13 terminal and boot
for the coil end and spark plug wire length of 5 inches.
If they do not get the trigger wire length correct then I have the
proceedures to adjust that length.
Jacobs Spark plug indexing washer set part #380800
8 (inch) piece of 1/2 shrink tubing
4 (inch) piece of 3/8 shrink tubing
NOTE: shrink tube was purchased at a local electronics store
(not Radio Shack), the stores name is Norvac electronics.
If you just can not find any shrink tube I will send you two
pieces cut to the proper length if you send me a stamped
self addressed envelope, send it to:
Marc L. Summers
11835 S.W. 113th Place
Tigard Oregon, 97223-4105
4 3924 Autolite Spark plugs
Aluminum plate .125 thick 5 (inches) long and 2.5 (inches) wide
2 rubber bushings .500 high, .770 dia. .240 center hole
2 (1&1/2) inch bolts .233 dia (measurement made with dial calipers
clamped down on threaded part of bolt.
2 nuts for those bolts
===============================================================================
PARTS RETRIVED:
Two rubber bushings and two screws that held down the stock
air box.
===============================================================================
ASSEMBLY OF THE OMNI PAK MOUNTING PLATE:
Using the dial calipers, or some other measuring device if you have
no dial calipers, we are going to measure and drill two holes that
the Omni Pak will screw down to.
Measure over from one of the 2.5 inch sides, .836 and mark a straight
line, do this on both ends.
Now measure over from the 5 inch side, .260 and mark a straight line
where these two lines cross is where you drill a .235 hole on each end.
Now measure in from the 2.5 inch sides .870 and mark a straight line
on each end, then measure center of the 2.5 inch wide, and mark a line
to cross the previous lines made. Where these lines cross drill
a hole .230 dia. NOTE: the distance between these two hole centers
should be approx. 3.135 This is the distance for the centers
of the two larger mounting bolts that were retrieved from the stock
air box.
==============================================================================
START BY SETTING UP YOUR TOWELS AND TOOLS:
Spread your bath towels over the rear of the car and over both the
drivers side (US) and the passengers side (US) of the car.
Lay out the tools that you will need so as they are in easy reach.
===============================================================================
MOUNTING THE PLATE IN THE CAR:
Assuming that the HKS super power flow air filter has been installed
properly, then it should already be using the lower left screw hole
on the mounting plate that the stock air box was mounted to.
The two remaining empty holes should be diagonal from each other one
in the upper left and one in the lower right as you look down on the
plate from the drivers side (US).
Assuming that you have measured and drilled the holes properly then
assemble the two large screws and rubber bushings from the stock air
box, we will do the left screw/bushing first, setdown the rubber bushing
and then the aluminum plate on top and then the screw/washer combo
screw the bolt down just a little, then do the same for the other right
side bolt plate bushing combination. Using the 12mm socket the 10 inch
drive extension and 3/8 drive ratchet, tighten the two bolts in place.
NOTE: notice that the placement of the plate should be such that the
two mounting holes for the Jacobs Omni Pack are towards the left
side of the plate and back as you look at it on the diagonal.
ie.(towards the side of the car as apposed to towards the engine.
MOUNTING THE JACOBS OMNI PAK:
First you will need to shave off the front right corner of the
Jacobs Omni pak so that it will clear the Air canister.
Orientation, orient the Jacobs so that the black wire group and the
high tension terminal are facing away from you, and the top of the
Jacobs is up. Using a hack saw saw off about a 1/2 inch corner piece
such that it makes a small triangle off the right front corner of the
Omni pak.
Now comes the hard part, mounting the Jacobs Omni pak to the aluminum
plate. Start with the left side screw first, be careful not to drop
things as I did, they are difficult to retrieve.
Orientation of the Jacobs Omni Pak is such that the black (four wire)
group and the high tension terminal are pointing at a diagonal towards
the distributor cap. I call this the front of the Jacobs omni pak.
As you look at the side runners on the Omni pak, you see a hole, a
slot, and another hole going from either front to back or back to front.
First using the 10mm box end wrench, take a small piece of scotch tape
and wrap it around one side of the box end so as to form a cup that the
nut will set in. This will allow you to place the nut on the bolt with
out dropping it.
Now open the small tube of lock tite and put just a little on the
end of the bolt and maybe a little on the nut also.
Insert the 1&1/2 inch bolt through the rear hole (not the slot)
position the Omni pak on top of the plate, and then slip one rubber
bushing (one that you purchased), under the Omnipak such that the Omni
pak sets on top of the bushing, then press the bolt down in place so
that it extends through the hole in the plate. Use the 10mm/nut combo
prepaired and position it with your left hand,(I'm right handed)
and have the 14 inch 1/4 inch drive extension, 10mm socket and
1/4 drive ready in your right hand, position the nut and start turning
the bolt until it catches on the nut.
Tighten it only part way. Now comes the really hard part.
The 10mm box end/ nut combo did not work for me on the
right bolt because the rubber bushing for the plate mount gets in the
way, so I had to position the nut with my left hand twisted around
clock wise about 90 degrees. Push the bolt up so that it is flush with
the bottom of the plate, then position the nut, (I assume that you put
some lock tite on them already), now with your right hand use the
14 inch extension and 10mm socket and 1/4 drive and turn the bolt while
with your left hand trying to position the nut. It is VERY difficult
to do, and it took me about 20 minutes of trying to do it. Perhaps
if you see a better way to do this, you might try that. Anyway, I did
finally get the nut started on the bolt. After that, then tighten each
bolt just a little in turn, going back and forth until they both are
tight.
WIRING THE JACOBS OMNI PAK:
SECOND WARNING: the wiring measurements that I give should be treated
as approximations, measure the wire for your self, you may not want to
install it just exactly as I did.
-----------------------------------------------------------------------
NOTE: at this time plug in your soldering iron so that it is getting
hot.
I measured and cut 53.5 inches off the black(four wire group) comming
out of the Omni pak. Now peel back about 5 or 6 inches of the tough
outer black sleeve of the four wire group. I used a knife and scored
the outer surface of the black plastic sleeve and peeled it back.
Be careful not to cut into any of the four inside wires.
Once this is done cut the white wire down to a stub, as it is not used.
Cut 1/4 inch of the insulation from the red, green and black wires.
Using one of the electrical terminals with the 1/4 inch hole in the
center, and accepts size 20 or 22 wire, push the end of the black wire
into the crimping end of the electrical terminal, and crimp it with
a crimping tool or a pair of pliers or cutters(be careful), and then
using the soldering iron and solder, solder the terminal to the wire.
Now we move our attention to the (two wire) connector comming out of
the top of the stock coil. If you use the mirror and flashlight you
can see the small locking mechanism that holds the connector in place.
Either position a small flat blade screw driver or your finger nail if
you have them, and pry up the small tab on the lock and then pull the
connector straight off. As you look down just off the end of the fuse
box, you notice a large wire bundle comming out of the end of the fuse
box, follow it just a little ways, and you will see that the two wire
connector comes out of the right side of it. Push up the connector so
that it comes up the right side and out on top of the large cable group.
Now you have a little room to work on it. You notice that the two
wires are covered by a loosely fiting plastic sleeve, using the small
wire cutters, nip away at the sleeve making a cut about an inch or so
long, remove that section of sleeve. Be careful not to cut the wires.
NOTE: the two wires in this operation are NOT cut from the connector.
We are going to TAP into them as the ECU demands that the stock coil
MUST be hooked up or the ECU will shut down the car.
Once the outer sleeve is cut away, you will notice two wires one a
thicker black/red stripe, and one a thinner black/white stripe wire.
We will work on the thicker black/red stripe wire first. We are going
to proceed to stagger two insulation cuts on these two wires so that
the bare wires are not directly adjacent to each other. Grasping the
thicker black/red stripe wire, carefully shave the insulation off the
wire using a sharp knife or exacto knife, be very careful not to cut
down into the copper wire. WARNING: given that an exacto knife can be
very sharp, there may be a tendency to use too much pressure and cut
through the wire. This removal of the insulation should be positioned
closest to the end of the outer sleeve. Once this is done and the bare
wire is exposed, locate the red wire comming out of the Jacobs Omni pak.
Feed the wire down and under the large wire group comming out of the
fuse box, and up to the exposed bare wire on the black/red striped wire.
Make a small bend and bend the red Jacobs wire so as to wrap it around
the bare part of the black/red striped wire. Make a fairly good
mechanical connection. Now with the soldering iron, and solder, solder
the two wires together. Make sure you leave the iron on there long
enough to make a good bond. Now, I used some special transformer tape
that I had, but since you don't have such tape, then lay down a 4 inch
piece of black electrical tape, and using the scissors cut down the
center of it such that it is 1/4 inch wide strip about 4 inches long.
Feed that strip of tape onto the area you just soldered, wrapping it so
that it covers the area well.
Now we are going to strip a similar 1/4 inch piece of insulation from
the black/white stripe wire, but remember to stagger it so that
it is not directly accross from the other joint. Once you have removed
the insulation, then feed the green wire from the Jacobs down and up on
the right side of the large wire group comming from the fuse box and up
to the bare wire. Wrap the end of the green wire onto the black/white
stripe wire, and then as you did on the other, solder the two wires
together. Now with another 4 inch piece 1/4 wide strip of elec. tape
wrap this connection well. Now using a 5 or 6 inch piece of 1/4 wide
black electrical tape, bundle the wires together and wrap the whole set.
Now push the connector back down the right side of the large wire group
comming from the fuse box, and position it so that you can press it
back onto the stock coil. You may need to use the flashlight and the
mirror to check the orientation. Once pressed in place, then use the
flashlight and mirror to check that it seated properly.
As you look at the black (four wire group) comming out of the omni pak
it goes over to and under the large group of wires comming out of the
fuse box, at the point where the Jacobs wire crosses under this large
wire group, use a 7 inch tie wrap and tie wrap the jacobs wire in place
to the large wire group comming out of the fuse box.
WIRING THE UNIVERSAL TRIGGER:
If you are as I was, Jacobs did not send me the proper universal trigger
wire, the right length. So rather than sending it back, and having to
wait yet another two or three weeks, and since it already had the proper
terminal I then proceeded to modify the universal trigger myself, which
proved to be a very simple job.
I will explain this proceedure now. NOTE: if you were able to get jacobs
to send you the correct length wire, then ignore this.
REDUCING THE LENGTH OF THE HIGH TENSION WIRE ON THE UNIVERSAL TRIGGER:
----------------------------------------------------------------------
WARNING: when shrinking the heat shrink with what ever heat source you
decide to use, please be careful that you do not OVER heat the
area.
Notice where the high tension 8mm wire comes out of the end of the PC
board, using a small pair of cutters clip and cut back about a 1/2 inch
piece of the large shrink wrap. You will see that the high tension 8mm
wire is held in place by a tie wrap. Cut the tie wrap and carefully
pull the wire off the end of the board and off the end of the resistor.
You will see the bare lead of the resistor now. I went out to the car
and held the universal trigger in place and placed the coil end of the
boot in place at the coil so that I could judge how long to cut it.
It turned out to be about 4 to 5 inches long. So I cut the high tension
8mm wire so that from the end of the boot to the end of the wire is about
4 to 5 inches long. Then press the bare lead of the resistor back into
the high tension 8mm wire and press the wire back into place in the PC
board. Now using a small 4 inch tie wrap, tie the wire in place. Pull it
tight. Trim off the excess end piece.
Now cut a measured size of 1/2 inch shrink tube and slip it over
the PC board so that at least 1/2 inch lap over the ends.
Use either a proper shrink tube heat gun or a cigarette lighter, heat the
shrink tube in place around the PC board. Now cut a 3 or 4 inch piece of
the 3/8 inch shrink tube and slide it over the two wire (green and black)
end of the universal trigger, lap it over the shrunk part of the 1/2
shrink tube, and use your heat source and shrink it in place.
------------------------------------------------------------------------
Now we are ready to install the universal trigger. Notice the stock coil
to distributor wire. Lifting the lock tab on the coil end, then pull the
wire connector off, and also on the distributor end, lift the small lock
tab and pull the distributor end off the distributor. I would suggest
keeping this in an easily reachable place ie.(your glove box), just in
case you might for some unknown reason need it. Then, press the boot
end of the universal trigger onto the stock coil. Press it on good, it
goes on just a little hard. The universal trigger PC board should now
be comming up on the left side of the large wire group comming from the
fuse box. Position the universal trigger PC board part so that it goes
diagonally across the side of the fuse box. Now locate the second
electrical terminal with the 1/4 hole in it, with the wire end for #18
or #20 I cut 32&1/2 inches off the black wire leaving about a 3 or 4
inch piece off the end, and cut the green wire down to a stub as it is
not used.
Strip a 1/4 inch piece, if you haven't already, off the
black wire comming from the end of the universal trigger. Place the
black wire in the end of the terminal and crimp in in place and then
using your solder iron solder the wire to the terminal.
Now notice to your right, as you lean over the drivers side of the car
a black relay that is screwed to a bracket. Using the 10mm socket and
1/4 drive or 10mm wrench, remove the bolt holding the relay in place.
You should now have two black wires with electrical terminals that you
soldered to the ends, one comming from the 4 wire group from the Omni pak
and one comming from the end of the universal trigger. Feed on one of
the 1/4 inch star washers, then the two black wire terminals, and then
a second star washer making a kind of sandwich. Then position the
relay and press the bolt in place and screw it down using either the
10mm wrench or the 10mm socket and drive.
Now notice that the PC board of the universal trigger runs kind of
diagonally across the side of the fuse box. Right in the center of
the fuse box as you look at it leaned over the drivers side (US) of the
car, there is a kind of tab hook holder that holds the top of the fuse
box in place. On the lower lip of the holder you will feed a 7 inch
tie wrap down through the lower lip, and up and around the PC board of
the universal trigger. Tighten this tie wrap, and flush cut the free
unused end. You will also notice that by using this lower lip of the
fuse box, that it does not interfere with the removal of the fuse box
lid.
INSTALL THE JACOBS TO DISTRIBUTOR HIGH TENSION WIRE:
Locate the jacobs to distributor high tension wire and press the jacobs
end on to the jacobs omni pak such that the wire goes down and away from
the top of the jacobs omni pak. Now press the distributor end onto the
center of the distributor making sure that the boot seats well.
NOW GO BACK AND CHECK YOUR WORK:
Check that the omni pak is mounted securely and can sort of bounce a
little on the rubber bushings. Check that the high tension wire comming
out of the omni pak does not come in contact with the four wire group
just below it. If it does move them slightly so that they do not touch.
Check that the four wire group comming out of the omni pak is tie wrapped
to the large wire group comming out of the fuse box. Check that the
two wire connector on the stock coil is on and locked in place.
Check that the PC board of the universal trigger is tie wrapped to the
lower lip of the fuse box holder. Check that the two black wires, one
from the omni pak, and one from the universal trigger have electrical
terminals soldered to them and that they have been securely bolted in
place on the bolt that holds down the small relay just next to the
right of the fuse box.
STARTING THE CAR:
Once you are satisfied that the wiring is correct then jump in the
car and it should start up immediately. (Mine did!)
If there is some problem, go back and check your wiring.
INSTALL AND INDEX THE NEW SPARK PLUGS:
WARNING: make sure you read the instructions that come with the
Jacobs indexing washers, or what ever indexing washers you
decide to use. REMEMBER: that you can only use ONE washer
at a time, NEVER STACK THEM.
Locate your four 3924 autolite spark plugs, and your gapping tool.
Remove the crush washer that comes with the spark plug.
(NOTE: this assumes that you are going to follow the indexing as I
have outlined below.)
Gap the four plugs at .031 (stock gap), NOTE: if you have made any other
modifications to your car such that the stock boost pressure goes any
above 10 pounds or is already at 10 pounds of boost, then making the gap
any larger than stock gap could cause the spark so be blown out at the
higher boost levels. I DO NOT recommend going to any larger gap.
Jacobs may or may not recommend a gap even as high as .050 or .060
DO NOT use a gap that large, it will not work at higher boost levels.
Once all of the spark plugs are gapped, then locate your long 3/8
extension, the 5/8 spark plug socket and the ratchet drive.
Use a short piece of the duct tape and tape the 5/8 socket to the
end of the extension bar. This is so it will not pull off and then
be a pain to pull out of the spark plug well. Leaning over from the
drivers side (US), firmly grasp the closest spark plug boot and pull it
up. NOTE: work on these ONE AT A TIME. DO NOT remove all of the spark
plug wires at once. Completely remove this one spark plug wire assembly
ie.(wire and boot ends. Locate the Wesleys Black Magic and spread a
little of it on a clean rag. Then using it, wipe off the large spark
plug boot assembly and the smaller distributor connector end. Lay it
asside for now.
Charge up your air compressor to about 100 psi, and blow out the inside
of the spark plug well, (BEFORE YOU REMOVE THE SPARK PLUG), If you don't
have a compressed air source you might try using a vacum cleaner with a
small hose attachment such as comes with some car cleaning accessories.
Now using the 5/8 spark plug socket/extension assembly and the 3/8 drive
ratchet break loose the spark plug and unscrew it and pull it out of
the spark plug well. Now would be a good time to examine your plugs for
what ever information you can obtain from them.
Now place the spark plug in the 5/8 socket/extension assembly. Cut a
small narrow strip of tape and place it on the extension such that it
lines up with the open end gap side of the spark plug and is easy to see
when the extension is placed in the spark plug well.
Open the pack of .043 copper indexing washers, and place one of them over
the end of the spark plug. As it sets at the bottom of the spark plug
threads, using a pair of pliers gently squeeze the copper washer just
a little bit so that it can not fall off the end of the spark plug.
Now locate your tube of anti sieze and place a liberal amount of it on
the threads, spreading it around with your finger and removing the
excess at the same time. Wipe the excess off your finger on a rag.
Now place the spark plug/socket/extension assembly down the well and
screw the spark plug down but not down to torque. Now check the owners
manual or read the back of the box of spark plugs for the proper torque
spec. There is a difference for iron and aluminum blocks.
Set your torque wrench to the proper torque, and torque it down, at the
same time checking where the thin piece of tape on the extension is.
When properly indexed it should be pointing towards the rear of the car.
Being that there are two intake valves and that one of them opens from
0 to 4200 rpm and that the other opens at 4200 rpm + then since I do
most of my driving at below 4200 rpm, I would point the open gap of
the spark plug at that valve. (NOTE: at the time of this writing I do
not know which valve is which). So I pointed my gap in the center of
the two valves, or 180 degrees from dead top, ie.(face of block towards
the front of the car.)
If that .043 copper washer does not index the spark plug properly then
try the next size. Remove the spark plug and squeeze the copper washer
such that it can now be removed from the end of the spark plug and try
the next sized washer. If it doesn't work then try the third size.
You should find, as I did, that one of them will set the gap fairly close
to where it should be. After you have this spark plug indexed and
torqued then replace the stock spark plug wire and boot assembly and
proceed on to the next one. Follow the same proceedure with it also.
Now when you get to the third spark plug over from the drivers side (US)
you will have to switch sides and go over to the passenger side (US)
to complete the operation. The third spark plug or the one under the
pipe that comes from the intercooler, is a little bit of a problem.
Here's what I did. You will have to work at it a bit, unless you have
a proper spark plug boot puller, (I did not), and pull the boot off.
Remove the wire/boot assembly as the others, and clean it with some
Wesleys Black Magic. Lay it asside for now. Locate and assemble
the following: 14 inch 1/4 inch drive extension, 1/4 to 3/8 adapter,
Using a piece of duct tape, tape the adapter to the end of the drive
extension. Then place the 5/8 spark plug socket on the adapter and tape
it to the extension also.
The 1/4 extension allowed me sufficient room to easily remove the old
plug and place the new one. WARNING: torquing with a long thin drive
extension may give you a false torque reading, to do the torque use
the 3/8 drive extension on this plug.
After having done the third spark plug then move on to the fourth and
complete it, but you can use the 3/8 extension assembly because it is
easily accessible.
After you have finished all, and replaced the stock wire and boot
assemblys, then check your work, make sure that the wires are placed back
in the seperators properly.
CHECK THE ENGINE STARTS:
Now start up the engine and check that it runs OK.
CLEANUP AND YOUR DONE:
Clean up your area and put all of your tools away for another day.
ADDENDUM
See article on using Jacobs spark plug wires.
Marc L. Summers