Custom EMS update

[KitCarlson]

Work on the wiring harness has started. It looks a mess at this point, however the work is constructive. I used the bulkhead pinout privided by Jon Martin and the PM/LM pinouts from the EFI information on Donovan's website. The information is great! The color codes are very helpful.

I started with a rough and abused Omni GLHT harness, and a few connectors from a Daytona donor car. The harness was stripped of all the tape and outer loom to find the wires. The wiring between the LM and PM was eliminated. The remaining PM contol wiring was re-routed to the A/C bulkhead location. About 25% of the wiring has been eliminated. I expect about another 10% removed in length since the new location seems optimal.

New loom will be used and the wiring attached at stock locations under the hood.

I carefully removed the A/C and plan to sell it. I replaced it with a 86 fresh air system. That took longer than expected.

On the custom EMS, I am using two units, a master and a slave. I did this to gain more I/O. Since the units are very small and light, together they are about 1/2 the size of the OEM LM. The PM electronics was pulled from the box and the connector holes plugged. An internal plastic part was cut to improve air flow. It still provides the fresh air intake. The EMS units will be installed in the area near the A/C bulkhead.

I wrote some software for serial communication at 115Kb/S, full duplex between the units. The engine controller is the master and the slave provides more sensor information and additional I/O. The slave code is simple, all control is still provided by the master. I did not want to have to re-flash the slave a bunch of times. The I/O drives solenoids and fan control. It also provides the atmospheric readings eliminating the baro solenoid. Both units have a second serial port for debug and development control.

More later ...