1992 LT-1. no start C-12 code
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
If you want to confirm your spark IS or ISN'T the issue perform this test:
Unplug one of your plug wires from a spark plug (any of your plug wires).
Use another spark plug (to be used as a tester) or an actual spark tester. Ground that device to the tip of the plug which you removed the test plug wire from.
Since THAT spark plug is still screwed into your cylinder, a spark produced outside the engine at your tester has to find ground by going through the plug (and jumping it's gap) still screwed into the cylinder, under compression.
If you get spark performing this test, then spark is not your problem.
Unplug one of your plug wires from a spark plug (any of your plug wires).
Use another spark plug (to be used as a tester) or an actual spark tester. Ground that device to the tip of the plug which you removed the test plug wire from.
Since THAT spark plug is still screwed into your cylinder, a spark produced outside the engine at your tester has to find ground by going through the plug (and jumping it's gap) still screwed into the cylinder, under compression.
If you get spark performing this test, then spark is not your problem.
Drifting
Joined: Dec 2007
Posts: 1,647
Likes: 4
From: Argillite KY
f you want to confirm your spark IS or ISN'T the issue perform this test:
Unplug one of your plug wires from a spark plug (any of your plug wires).
Use another spark plug (to be used as a tester) or an actual spark tester. Ground that device to the tip of the plug which you removed the test plug wire from.
Since THAT spark plug is still screwed into your cylinder, a spark produced outside the engine at your tester has to find ground by going through the plug (and jumping it's gap) still screwed into the cylinder, under compression.
If you get spark performing this test, then spark is not your problem.
Unplug one of your plug wires from a spark plug (any of your plug wires).
Use another spark plug (to be used as a tester) or an actual spark tester. Ground that device to the tip of the plug which you removed the test plug wire from.
Since THAT spark plug is still screwed into your cylinder, a spark produced outside the engine at your tester has to find ground by going through the plug (and jumping it's gap) still screwed into the cylinder, under compression.
If you get spark performing this test, then spark is not your problem.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
are you SURE there isn't a C41 code?
IF so, the car WILL NOT START! That means the PCM and CCM have lost comms and the CCM can't provide the PCM with the necessary handshake to say "start that sucker".
If you turn on the key, do you see "SYS" on the Speedo?
IF so, the car WILL NOT START! That means the PCM and CCM have lost comms and the CCM can't provide the PCM with the necessary handshake to say "start that sucker".
If you turn on the key, do you see "SYS" on the Speedo?
Thread Starter
Instructor
Joined: Nov 2012
Posts: 242
Likes: 4
From: Grand Island - Nebraska
There is a 41 code. I used an in-line spark tester and it is getting some spark. There is always a SYS flash due to the stereo replacement. I get an H41 due to the fact that it never really starts to begin with. If the communication between the two parts is the problem, where can I isolate it to diagnose it. I thought I should look at the fuse block behind the battery too.
Thread Starter
Instructor
Joined: Nov 2012
Posts: 242
Likes: 4
From: Grand Island - Nebraska
There is a 41 code. I used an in-line spark tester and it is getting some spark. There is always a SYS flash due to the stereo replacement. I get an H41 due to the fact that it never really starts to begin with. If the communication between the two parts is the problem, where can I isolate it to diagnose it. I thought I should look at the fuse block behind the battery too.
Racer
Joined: Oct 2003
Posts: 475
Likes: 21
From: CLAREMONT Ca
Did you ever resolve your problem? What did it turn out to be?
I now have 40lbs at prime and it is holding at 35lbs after 1 hour. Per the FSM protocol, it is saying that the ECM is faulty. When I ran the spark test, it seemed rather weak. I am only going on what I am testing and reading, but it seems like there is a lack off real spark to get the motor going. The coil is new and the opti and harness is new. I will test further into the ECM tomorrow. Any ideas between now and then are appreciated.
