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Hoping someone can help sort out this issue. My 69 427 400hp won’t start until I release the key from the start position. It cranks and cranks fine, but won’t fire until the key is released to the on position. Do I have a wire misplaced or broken? Any ideas?
points? R wire is not hooked up from distrib + to R terminal on starter. spark is too weak thru resistor wire to fire when starter is drawing the volts down. it could also be your spark is also getting a bit weak and point gap and dwell and timing needs tweaked. it will usually start without the R wire. it is pretty much there for when you need a tune up.
Last edited by derekderek; 07-23-2020 at 08:23 PM.
No. It has the optional OEM electronic ignition. There are no points and no condenser. There’s a factory installed magnetic coil and a pickup inside the distributer with an electronic control box mounted on the drivers side wheel well. All 100% GM.
When the engine is cranking or running you should see voltage pulses (zero, +12v, zero, +12v etc.) at the +terminal of the ignition coil. It is easiest to see these pulses with an analog (needle-type) volt meter. I would hook up a volt meter and see if you are getting those pulses when cranking. If not, then you need to work back from that point to find out why.
Hoping someone can help sort out this issue. My 69 427 400hp won’t start until I release the key from the start position. It cranks and cranks fine, but won’t fire until the key is released to the on position. Do I have a wire misplaced or broken? Any ideas?
Sounds like the Crank side of the ignition module is bad to me and then fires from the Run side when you let off the key . Not sure how the early style electronic ignition works without seeing some schematics , maybe it’s not seeing the Crank signal from the ignition switch like the starter is
No. It has the optional OEM electronic ignition. There are no points and no condenser. There’s a factory installed magnetic coil and a pickup inside the distributer with an electronic control box mounted on the drivers side wheel well. All 100% GM.
K66 TI Thinking HEI
Sorry about that,
If you have a 3 terminal solenoid check the R terminal for 12V in crank
Yea, that’s what I’m afraid of. Way over my head on this. It’s an NOS unit that our local corvette guru (since closed shop and gone) sold to me and installed for me. The box was upgraded with a new circuit board, but that’s all I know. I may have to search out another guru……🤔. Not going to update anything since she’s all original.
A couple things have my curiosity. 1) As mentioned earlier, the ignition switch, if operating properly, should supply voltage during both cranking and run condition. 2) the starter solenoid R teminal should feed voltage to the TI module, shunting the ignition line ballast resistor for better starts at low battery voltages. (Posts 10 and 11 above)
Are either of these voltage source lines open/intermittent?
Last edited by 69427; 07-23-2020 at 10:04 PM.
Reason: Added Post numbers
A couple things have my curiosity. 1) As mentioned earlier, the ignition switch, if operating properly, should supply voltage during both cranking and run condition. 2) the starter solenoid R teminal should feed voltage to the TI module, shunting the ignition line ballast resistor for better starts at low battery voltages. (Posts 10 and 11 above)
Are either of these voltage source lines open/intermittent?
.
I’d have to find a way to check. No ballast resister in the system but I think there is a resistance wire. All wiring harnesses were new and are still like new when installed several years ago but I’ve only put 4000 miles on it since it was restored. I can’t imagine that there is anything wrong with the wiring harnesses. Maybe a bad connection. I'll just have to jack it up and have a look I guess.
The Factory K66 (TI) has a couple of resistors in the harness. As 69427 noted, the "R" terminal on the starter solenoid is used to bypass those resistors. Service manual wiring diagram is attached below..
Yea, that’s what I’m afraid of. Way over my head on this. It’s an NOS unit that our local corvette guru (since closed shop and gone) sold to me and installed for me. The box was upgraded with a new circuit board, but that’s all I know. I may have to search out another guru……🤔. Not going to update anything since she’s all original.
The Factory K66 (TI) has a couple of resistors in the harness. As 69427 noted, the "R" terminal on the starter solenoid is used to bypass those resistors. Service manual wiring diagram is attached below..
Nope. Mine is exactly as shown on the schematic you sent. A big white resister wire to the positive side and a smaller black wire to the negative side of the coil. No third wire to the positive side of the coil.
I’d have to find a way to check. No ballast resister in the system but I think there is a resistance wire. All wiring harnesses were new and are still like new when installed several years ago but I’ve only put 4000 miles on it since it was restored. I can’t imagine that there is anything wrong with the wiring harnesses. Maybe a bad connection. I'll just have to jack it up and have a look I guess.
[QUOTE=69 Coupster;1601892491]Nope. Mine is exactly as shown on the schematic you sent. A big white resister wire to the positive side and a smaller black wire to the negative side of the coil. No third wire to the positive side of the coil.[/QUOTE]
If there was a third wire going to the coil positive terminal it would blow up the coil the first time you tried to crank the engine.
Quit arguing with guys here that know more about the TI system than you do.
Nope. Mine is exactly as shown on the schematic you sent. A big white resister wire to the positive side and a smaller black wire to the negative side of the coil. No third wire to the positive side of the coil.[/QUOTE]
If there was a third wire going to the coil positive terminal it would blow up the coil the first time you tried to crank the engine.
Quit arguing with guys here that know more about the TI system than you do.
Listen and learn.
I’m sorry I think you are mistaken. I’m not arguing With anyone. It was suggested that I should have a third wire on the coil and I was just verifying that I do not. That’s all. Sorry If you miss understood my comment.
07-23-2020, 08:08 PM
Won’t fire until I release the key
