Low cost MINI-STARTER
03-05-2018, 03:24 PM
#61
Rennlist Member
There are definitely only two terminals on the IMI starters, the stud for the 12V battery connection and the spade terminal for the starter-switch to solenoid connection. The pale blue cover is the internal connection between solenoid and motor. The solenoid does two things: It pushes the pinion gear into engagement with the ring-gear on the flywheel, and closes a high-amperage switch contact between the battery connection and the motor itself.
The wiring diagram for the '84 does indeed show a third connection on the starter for the US/Japan cars, so I guess you are not crazy
The extra connection is a second switch contact which connects the 12v battery lead directly to the ignition coils, bypassing the two resistors. Prior to electronic ignition, coils would overheat if fed with a constant 12 volts so a ballast resistor was used to limit the current. However the battery voltage drops when starting, so there is a bypass to provide full voltage to the coils when cranking. This is the third terminal.
And yes, a diode from the starter-switch contact will accomplish the same thing and work fine. (Never bet against GB, by the way). I don't know what the coil current would be, but I would think a 10 or 20-amp rectifier diode would do nicely. The "arrow" (direction of current flow) points towards the coil.
But are you sure that your starter is the problem? I would check over the connections and terminals carefully first. The IMI starters work fine and are really nicely made, but it is hard to say that they are "better" than the stock starter for stock applications. Mostly they get used to provide clearance for a pan spacer or some other necessity.
There is one more wrinkle with the IMI, the orientation of the 12v stud which I will post shortly.
The wiring diagram for the '84 does indeed show a third connection on the starter for the US/Japan cars, so I guess you are not crazy
The extra connection is a second switch contact which connects the 12v battery lead directly to the ignition coils, bypassing the two resistors. Prior to electronic ignition, coils would overheat if fed with a constant 12 volts so a ballast resistor was used to limit the current. However the battery voltage drops when starting, so there is a bypass to provide full voltage to the coils when cranking. This is the third terminal.
And yes, a diode from the starter-switch contact will accomplish the same thing and work fine. (Never bet against GB, by the way). I don't know what the coil current would be, but I would think a 10 or 20-amp rectifier diode would do nicely. The "arrow" (direction of current flow) points towards the coil.
But are you sure that your starter is the problem? I would check over the connections and terminals carefully first. The IMI starters work fine and are really nicely made, but it is hard to say that they are "better" than the stock starter for stock applications. Mostly they get used to provide clearance for a pan spacer or some other necessity.
There is one more wrinkle with the IMI, the orientation of the 12v stud which I will post shortly.
Here's my idea to hook up my three wire car to the IMI starter. Does that make sense to you?
Thanks,
Dave
03-05-2018, 03:27 PM
#62
Rennlist Member
Here's the connection wrinkle: The battery terminal is at the back of the stock starter, while the IMI terminal is on the side, and the battery cables are large. I had to torture the two old/stiff factory cables to connect them, it worked but they were not happy-- lots of stress on the connection.
The other problem was that the battery stud was not long enough for the two factory cable terminals and the nut, only one or two threads were engaged:
I scratched my head a bit, thought about a separate connection post, and then contacted Matt at IMI for ideas. He immediately sent a right-angle terminal which resolved both issues:
Everybody is happy now, and Matt was very responsive and great to work with:
Your mileage may vary depending on terminals and how flexible your battery cables are, but if you run into an issue this was the perfect solution.
03-05-2018, 03:31 PM
#63
Rennlist Member
You are a stud, Jim. Pun intended. I called and they will include the extension terminal with my order.
What can I say. Thanks again,
Dave
What can I say. Thanks again,
Dave
03-05-2018, 10:06 PM
#64
Rennlist Member
..... The one thing I will need to do is cut the ring connector for the starter switch from my new harness and change it to the spade connecter for this. That's a bit of a bumper. I wish this had a post style so I didn't have to modify my harness. It will be a while before I install this guy, I need to finish some interior and AC work first. Maybe this spring.
I ordered this starter thanks to yours and Jim's documentation. I was thinking of cutting off my small ring terminal, and adding a splice. I would shrink wrap and make it look good. I'm trying to see a drawback to this method vs. two ring terminals joined by a very small screw, also shrink wrapped. Any opinions?
Thanks,
Dave
03-05-2018, 11:41 PM
#65
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The drawback is destructive modification of the engine harness. If you ever want to go back to the OE starter you'd have to cut and splice again.
03-07-2018, 06:00 PM
#66
Rennlist Member
Hi Guys,
I called IMI on Monday and ordered their starter. It got from California to Chicago today, Wednesday. It looks like a nice item. It is exactly like pictured above. On my car I used the outboard configuration as Jim described above (not as he pictured), and just as IMI clocked the unit. I tried it 180* opposite, just to see. I had some oil pan interference, so I went back to the outboard setting. I used the right angle terminal extension as Jim pictured. It all fits very nicely. The upper starter bolt is a bear to tighten.
I am waiting for my diode to come, so I'll finish the electrical install soon.
So far it looks good, fits well, and I'm confident it will work well also.
Thanks for all the help,
Dave
I called IMI on Monday and ordered their starter. It got from California to Chicago today, Wednesday. It looks like a nice item. It is exactly like pictured above. On my car I used the outboard configuration as Jim described above (not as he pictured), and just as IMI clocked the unit. I tried it 180* opposite, just to see. I had some oil pan interference, so I went back to the outboard setting. I used the right angle terminal extension as Jim pictured. It all fits very nicely. The upper starter bolt is a bear to tighten.
I am waiting for my diode to come, so I'll finish the electrical install soon.
So far it looks good, fits well, and I'm confident it will work well also.
Thanks for all the help,
Dave
03-07-2018, 07:33 PM
#67
Inventor
Rennlist Member
Rennlist Member
03-07-2018, 08:01 PM
#68
Rennlist Member
03-07-2018, 08:37 PM
#69
Rennlist Member
03-07-2018, 10:18 PM
#70
Nordschleife Master
I think that "inventor" tag indicates that he's at least 'sorta smart'.
I'm just happy he's directed his smarts at these cars, instead of, say, a Honda.
Ya know?
03-07-2018, 10:39 PM
#71
Rennlist Member
Well I finished the electrical part of the install. I had to manipulate the female spade plugs to accept the ring connectors, but they ended up tight and secure. The car started right up. It sounds different, but I don't exactly remember what the old starter sounded like. The wiring looks neat, and the starter is quite compact. So far I'm happy with it. Hopefully it will be reliable.
Thanks for all the help.
Dave
Thanks for all the help.
Dave
03-08-2018, 02:00 AM
#72
Rennlist Member
Tease...
pics and and and audio file would be appreciated 😸
pics and and and audio file would be appreciated 😸
03-08-2018, 01:09 PM
#75
Rennlist Member