no spark

Suprajunkie · 06-04-2008, 05:49 AM

Just had this problem on my 83 Supra. Coil/Ignitor swap didn't help. I'd suggest checking to make sure your not getting spark from the coil, i.e. hold the coil wire close to a ground source (One of the bolts on the top of the strut tower works well) and have someone crank the engine. If you have spark, you have a problem in you distributor. If you don't have any spark, try swapping the coil/ignitor. They are pricey new, i.e. $350.00 and up, so try and find a used one, hopefully a known good one, and retry the spark test from the coil again.

Assuming you've swapped the coil/ignitor with a known good one and still have no spark, do the following: (You'll need a volt meter)

There are 4 connectors coming out of the coil/ignitor. One is typically not connected (test lead), one goes to the distributor, and the other two enter the wiring harness. These two are the one you want. One should be a dirty white/light yellow color. The other should be a brown/tan color.

In the following order:
Turn on the ignition. (run position, but not cranking)
Disconnect the two wires at the connector mentioned above.
Leaving the yellow wire loose, connect your volt meter to the wiring harness site of the brown wire. You should see approximately 12 volts.
If you are seeing 12 volts, voltage is making it to the coil/ignitor. Reconnect everything and try starting the vehicle.

If you do not see 12 volts, carefully inspect the connectors for corrosion or broken wires going into the connectors. (some contact cleaner wouldn't be a bad idea). Assuming the connectors are good, open the fuse box next to the coil/ignotor. You see two wires (fusibile links) that jumper between connectors. With the key on, use your volt meter to verify 12 volts on both sides of each wire. If you don't see 12 volts, or significantly less than 12, i.e. 8 volts, pull the wires on and off several times to clean the connection or use some contact cleaner.

If all the above fails to get voltage to the coil/ignitor, you could have either a ECU or ignition switch problem (both unlikely, but possible) Swapping the ECU isn't hard if you can find another one. I can't verify but was told that the ECU from and 82-85 would work, either manual or automatic. If you suspect your ignition switch is flakey (you'll usually have other indictors) try spraying a little WD40 into the key entry and work the ignition back and forth.

In my case, the brown connector was the culprit and it's running fine now.

Hope this helps!

06-04-2008, 05:49 AM	#4
Suprajunkie Stock Join Date: Jun 2008 Location: Oklahoma Posts: 2	Just had this problem on my 83 Supra. Coil/Ignitor swap didn't help. I'd suggest checking to make sure your not getting spark from the coil, i.e. hold the coil wire close to a ground source (One of the bolts on the top of the strut tower works well) and have someone crank the engine. If you have spark, you have a problem in you distributor. If you don't have any spark, try swapping the coil/ignitor. They are pricey new, i.e. $350.00 and up, so try and find a used one, hopefully a known good one, and retry the spark test from the coil again. Assuming you've swapped the coil/ignitor with a known good one and still have no spark, do the following: (You'll need a volt meter) There are 4 connectors coming out of the coil/ignitor. One is typically not connected (test lead), one goes to the distributor, and the other two enter the wiring harness. These two are the one you want. One should be a dirty white/light yellow color. The other should be a brown/tan color. In the following order: Turn on the ignition. (run position, but not cranking) Disconnect the two wires at the connector mentioned above. Leaving the yellow wire loose, connect your volt meter to the wiring harness site of the brown wire. You should see approximately 12 volts. If you are seeing 12 volts, voltage is making it to the coil/ignitor. Reconnect everything and try starting the vehicle. If you do not see 12 volts, carefully inspect the connectors for corrosion or broken wires going into the connectors. (some contact cleaner wouldn't be a bad idea). Assuming the connectors are good, open the fuse box next to the coil/ignotor. You see two wires (fusibile links) that jumper between connectors. With the key on, use your volt meter to verify 12 volts on both sides of each wire. If you don't see 12 volts, or significantly less than 12, i.e. 8 volts, pull the wires on and off several times to clean the connection or use some contact cleaner. If all the above fails to get voltage to the coil/ignitor, you could have either a ECU or ignition switch problem (both unlikely, but possible) Swapping the ECU isn't hard if you can find another one. I can't verify but was told that the ECU from and 82-85 would work, either manual or automatic. If you suspect your ignition switch is flakey (you'll usually have other indictors) try spraying a little WD40 into the key entry and work the ignition back and forth. In my case, the brown connector was the culprit and it's running fine now. Hope this helps!