Trigger Errors due to ignition coil

[Benzmac16v]

Hi,

So it has been a while since I have been on here because my primary trigger failed pretty hard and I had to redesign the whole thing and be a full time student 150 miles away from my car...

At any rate, I finally have the car all back together and it is cranking... only cranking.  I get primary trigger errors (some times too many sometimes too few) and they always come at, or very close to tooth 17.  After some work I have determined that the coils are putting the error on the trigger.  Cranking with no ignition fuse yields no trigger errors.  So I put the fuse back in and disconnected the spark plug wires from the coil, still get errors (although this time only too many primary trigger, which I found odd).  Unplug the coil from the ecu and the errors go away.

The only thing that has changed on the car are the the trigger wheel and sensor (the shielded wire on the sensor is the same as before) and the mounting bracket for the coils is now made from aluminum rather than steel.

I am pretty much stumped at this point, I know the shield is good (I have rewired the sensor trying to fix the issue) so I am not really sure where to go from here. 

Anyone got any ideas?

Thanks,
Jim

[Benzmac16v]

Replaced the battery with one of those large diesel ones.  The old battery was really poor and required jumping inorder to keep the voltage up while cranking, even after it was fully charged.

The new battery did nothing to fix the problem, was hoping there were some grounding issues with the old battery.  I will continue to check the grounds but this freaking 1800mile long snow,sleet, freezing rain storm just started so I wont be able to do much (no garage).  Any advice would still be appreciated.

Jim

[Benzmac16v]

Forgot to update this thread after I figured out the issue.

I had a custom sensor made using an Allegro hall effect sensor.  These things are tiny and have very good accuracy (http://www.allegromicro.com/en/Products/Part_Numbers/0625/0625.pdf).  The issue was the guy who made the sensor grounded it to the sensor body as well as the ECU ground.  So this made a huge ground loop and caused all the trigger errors when the coils fired. 

I ended up moving the trigger position from the "stock" location so I could fit a larger off the shelf sensor from cherry corp.

Figured I would just close out this topic in case someone else ran into the same issues in the future.

Jim