I wanted to get this caution out there to our customers on wiring and connector installation. We've seen a few instances now where people reported some strange issues with the engine running roughly and these took some time to troubleshoot and find the cause.
In two instances, the ECU connectors were not plugged in all the way. The 16 pin Molex connector at the end of the ECU carrying injector outputs, grounds for the coils and injectors and some other options, has a positive latch which will clearly snap in when engaged. Ditto for the same type of connectors used on the injector relay boxes. They cannot come loose if properly latched.
The D sub connectors used for Hall, programmer and sensor wiring have 4-40 screws on either side. Be sure these are plugged in all the way and the screws tightened down.
Please double check all connections before flying. Things can be forgotten if you get distracted and these are flight critical items.
The third thing we saw which took months to finally troubleshoot was due to ECU sensor wires being tie wrapped to the spark plug wires. The result was inconsistent running and eventually 2 fried ECUs. NEVER tie wrap any ECU wires to spark plug leads.
There is up to 40,000 volts on those leads and if you tie a sensor wire to it for any length, you can get inductive and capacitive coupling inducing voltages in that sensor wire far exceeding the logic levels normally present in the ECU which operates on only 5V. In this extreme case, current/ voltages on inputs went well over what protection circuitry is designed to deal with. (we figure over 400V to do this damage).
Finally, watch all those ground connections. They must be 100%. If the ECU cannot pull control devices to ground, it may not operate them properly, or at all. Don't stack any device grounds which have pulsing current loads (injectors, coil packs, strobes, electric motors etc. to the CPU ground (pin 18 on DB25). Use separate ground terminals for each CPU ground wire.
For wiring connections, be sure to look at our wiring page here: http://sdsefi.com/wiring.htm
and our MSD plug wire tutorial here: https://www.youtube.com/watch?v=5_sakmDb2fo
, plus our YouTube channel here: https://www.youtube.com/channel/UCiy...g2GvQfelECCGoQ
for other info.
We're also going to start stocking crimpers which will crimp most of the pins supplied with the kits. We'll make those available at near cost for system buyers so you don't need to search for one or try to use a tool which is not designed for the job.