Code 42: Electronic Spark Timing Circuit
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Code 42: Electronic Spark Timing Circuit
Car: 1987 Coupe, stock distributor, Accel Coil
Here is what I've found on it:
This is what I've done.
I parked the car about a month ago for a new power steering pump, and some massive cooling upgrades. When the car was parked, it was not throwing any codes. I had all of the accessories off the front of the car.
As far as I can tell, all of the wires are hooked up at the front of the engine. They definitely are at the back of the engine. The C- GND B+ wire connector is plugged into the coil, as are the Tach and Bat connectors. The four wire connector at the back of the distributor is also hooked up. The computer advance wire(lt brown wire) for the timing is hooked up. Timing is at 6 without computer advance.
When I hook the computer advance wire up, the idle does not get any smoother.
Right now she is idling at 430 rpms. The power brakes aren't working well, but I'm sure thats just because of the low idle. The only other symptom besides the idle is a surging acceleration. At constant throttle, about 1/2, I'll have spurts of higher acceleration, such as if I had pushed the throttle 1/8 more.
Could the ignition module go bad from sitting? The car sat all last summer while I put a new motor/trans in, and it was fine then. But this may have pushed it over the edge. Where is the ignition module? Is there any way to test it?
I don't know what else to check, any suggestions are appreciated. :cheers:
[Modified by NoWorries, 10:08 PM 8/2/2002]
Here is what I've found on it:
Check wiring at ignition module. Replace ignition module. Possible ECM failure.
I parked the car about a month ago for a new power steering pump, and some massive cooling upgrades. When the car was parked, it was not throwing any codes. I had all of the accessories off the front of the car.
As far as I can tell, all of the wires are hooked up at the front of the engine. They definitely are at the back of the engine. The C- GND B+ wire connector is plugged into the coil, as are the Tach and Bat connectors. The four wire connector at the back of the distributor is also hooked up. The computer advance wire(lt brown wire) for the timing is hooked up. Timing is at 6 without computer advance.
When I hook the computer advance wire up, the idle does not get any smoother.
Right now she is idling at 430 rpms. The power brakes aren't working well, but I'm sure thats just because of the low idle. The only other symptom besides the idle is a surging acceleration. At constant throttle, about 1/2, I'll have spurts of higher acceleration, such as if I had pushed the throttle 1/8 more.
Could the ignition module go bad from sitting? The car sat all last summer while I put a new motor/trans in, and it was fine then. But this may have pushed it over the edge. Where is the ignition module? Is there any way to test it?
I don't know what else to check, any suggestions are appreciated. :cheers:
[Modified by NoWorries, 10:08 PM 8/2/2002]
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Re: Code 42: Electronic Spark Timing Circuit (NoWorries)
Assure that the EST cable connection is solid for the code 42.
Clean and adjust the IAC and set the TPS to deal with the low idle.
Check/clean the MAF connections as it can cause both idle and surging problems.
Clean and adjust the IAC and set the TPS to deal with the low idle.
Check/clean the MAF connections as it can cause both idle and surging problems.
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Re: (scorp508)
Did you forget to plug the brown wire back together after setting the timing one day?
That wire won't throw a code. I know because my friend that helped me put the engine in forgot to hook it up, even though I asked him point blank if he did. We drove it 74 miles before rechecking the timing, and it was still unhooked.
This is the chain of events:
Canyon(NoWorries): "Hey, look the Comp. Advance wire isn't hooked up."
Lee(Foxspy): "I think I hooked it up. On second thought, maybe I didn't."
NoWorries Foxspy
[Modified by NoWorries, 10:21 PM 8/2/2002]
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That wire won't throw a code.
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Re: Code 42: Electronic Spark Timing Circuit (65Z01)
Assure that the EST cable connection is solid for the code 42.
Clean and adjust the IAC and set the TPS to deal with the low idle.
Check/clean the MAF connections as it can cause both idle and surging problems.
Clean and adjust the IAC and set the TPS to deal with the low idle.
Check/clean the MAF connections as it can cause both idle and surging problems.
The car doesn't die when I get off the throttle, although there is a very minor droop, probably to 410 rpm before it comes back up to 430. So I think the IAC is good, but I've been meaning to clean it, so I'll be doing that soon.
While searching I noticed one of the spark plug wires has a nick in the insulation. It didn't make it to the core, and there is no visible bleed through. However, I don't think that would throw a code.
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Re: Code 42: Electronic Spark Timing Circuit (NoWorries)
I recently had the same problem on my car. What I ended up doing is taking the ignition module to the auto parts store to have them test it, of course it checked out just fine. I went home and was in the process of putting the module back in so I could go pout when I noticed that one of the wires in the 4-wire harnass that plugs in to the module (same harness that leaves through the back of the distributor) was broken. After pulling the little beastie out of the car I find out that two of the wires were broken. Can't believe the car would still run. Soldered the wires, coated them with silicone, reinstalled, voila! No more Code 42.
Good luck
Good luck