Ti ignition problems
Thread Starter
Intermediate
Joined: Oct 2017
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Have you tried pulling the coil wire out of the distributor cap, and placing the end near a ground so that you can look for a spark while cranking?This would supply some information on where the problem might be.
Also do you have access to a couple simple parts like resistors and LEDs? I was thinking you could disconnect the coil C+ wire and have the module drive the LED instead of the coil, and you could do some cranking (or just momentarily shorting the white/green (?) distributor lead to see if the module correctly shuts off the current to the LED.
The TI system is very simple compared to later ignitions. It's easy to do some simple test debugging on it.
Also do you have access to a couple simple parts like resistors and LEDs? I was thinking you could disconnect the coil C+ wire and have the module drive the LED instead of the coil, and you could do some cranking (or just momentarily shorting the white/green (?) distributor lead to see if the module correctly shuts off the current to the LED.
The TI system is very simple compared to later ignitions. It's easy to do some simple test debugging on it.
So, I pulled the distributor wire and placed it next to ground and had the wife turn the key. A small spark at the beginning of crank and a small spark when the key was released was the result. Any Ideas? Sounds like the amplifier to me, how about you?
Tech Contributor
Joined: Jun 2004
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Just asking, because I remember a thread a couple years ago where a poster was having starting issues and there was a problem with his ignition switch (at the bottom of the column) doing funky things.
This might not be the/an issue, but just nice to know for everybody here so we can all eliminate one variable.
Melting Slicks
Joined: Oct 2001
Posts: 2,064
Likes: 1,382
From: Halifax, Nova Scotia, Canada
By "disconnecting" the wire from the starter to the TI harness, I would get good spark while cranking.
As I said before, this makes no sense at all, however it fixed that problem.
The only thing I did a while later was put a relay in the +12 ign feed.
Used the pink ign feed to pick/energize the relay, and the relay connected main power from the horn bus to the TI ign wire.
This gave a higher voltage to the TI while cranking.
The starter to TI wire remains disconnected and starting has never been this good.
Last edited by Barry's70LT1; Nov 10, 2017 at 01:32 PM.
Thread Starter
Intermediate
Joined: Oct 2017
Posts: 49
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Quick question just to refresh my memory. Are you getting voltage to the module during cranking? The small sparks at the start and end of cranking are possible if the supply voltage to the module & coil is toggling off and on when the ignition switch is moved from ON->CRANK->ON.
Just asking, because I remember a thread a couple years ago where a poster was having starting issues and there was a problem with his ignition switch (at the bottom of the column) doing funky things.
This might not be the/an issue, but just nice to know for everybody here so we can all eliminate one variable.
Just asking, because I remember a thread a couple years ago where a poster was having starting issues and there was a problem with his ignition switch (at the bottom of the column) doing funky things.
This might not be the/an issue, but just nice to know for everybody here so we can all eliminate one variable.
Tech Contributor
Joined: Jun 2004
Posts: 20,860
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I'm not following what you mean by "what is coming back from the amplifier that is deficient".
Thread Starter
Intermediate
Joined: Oct 2017
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Unplugging the module will tell us if there's a voltage source connected during cranking, but it doesn't tell us if the source is the ignition switch (through the harness ballast resistance) or if it's the low/zero resistance 12v feed from the starter solenoid. We need to somehow read the voltage at the module (while connected to the harness) during cranking.
I'm not following what you mean by "what is coming back from the amplifier that is deficient".
I'm not following what you mean by "what is coming back from the amplifier that is deficient".
Remember in the previous post that we determined that the ignition wire was resisted. I have not taken the dash apart yet to get to the ignition terminal to run a dedicated non-resisted wire. This measurement of voltage is while having a jumper wire from the horn relay (constant 12.4v) to the TI harness white wire. It should be unaffected by the ignition switch correct?
Tech Contributor
Joined: Jun 2004
Posts: 20,860
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
69427,
Remember in the previous post that we determined that the ignition wire was resisted. I have not taken the dash apart yet to get to the ignition terminal to run a dedicated non-resisted wire. This measurement of voltage is while having a jumper wire from the horn relay (constant 12.4v) to the TI harness white wire. It should be unaffected by the ignition switch correct?
Remember in the previous post that we determined that the ignition wire was resisted. I have not taken the dash apart yet to get to the ignition terminal to run a dedicated non-resisted wire. This measurement of voltage is while having a jumper wire from the horn relay (constant 12.4v) to the TI harness white wire. It should be unaffected by the ignition switch correct?
Refresh my memory. Have you done any cranking/starting attempts with the horn relay jumper wire hooked up? (Remember that the engine might not shut off with the jumper wire attached.)
I'm just trying to eventually get to a test where we can figure out if it's a voltage issue, a module issue, or a distributor sensor waveform issue.
Instructor
Joined: Sep 2012
Posts: 175
Likes: 2
From: Omaha NE
Hey just a thought ,
double check the main plug going to the amplifier I’ve read that it’s possible when your pushing it into the amplifier the that the interior connection can’t push in and you will not make the connection thinking you did.. Good Luck keep us posted
double check the main plug going to the amplifier I’ve read that it’s possible when your pushing it into the amplifier the that the interior connection can’t push in and you will not make the connection thinking you did.. Good Luck keep us posted
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Melting Slicks
Joined: Jan 2000
Posts: 3,326
Likes: 523
From: home
TI module should have a pigtail harness with the connector located somewhere near the generator. Make sure none of the terminals on the harness can touch the bottom of the cover for the amplifier.
Thread Starter
Intermediate
Joined: Oct 2017
Posts: 49
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Well gentlemen, thank you so much for your help. I have installed a HEI module in a similar fashion to the photos in the previous post and the car fired right up and runs great. I feel a bit defeated not being able to get to the bottom of the TI but enough time and money have been spent. Thank you all for the advice and I think this thread will be a great assistance to TI troubleshooters in the future.
Melting Slicks
Joined: Oct 2001
Posts: 2,064
Likes: 1,382
From: Halifax, Nova Scotia, Canada
Well gentlemen, thank you so much for your help. I have installed a HEI module in a similar fashion to the photos in the previous post and the car fired right up and runs great. I feel a bit defeated not being able to get to the bottom of the TI but enough time and money have been spent. Thank you all for the advice and I think this thread will be a great assistance to TI troubleshooters in the future.
