rusefi.com

Got my Jeep 4.0 engine running in ignition only mode, but as soon as the engine is running the ECU stops communicating with Tunerstudio.

In device manager the USB status is unknown device when engine is running.
It's communicating fine when engine is not running.
I can make adjustments in TS and everything seems fine.

Setup:
LS1 coil near plug
36-1 trigger on crank, Hall sensor.
No cam sensor yet.
ECU is in car, 2feet away from coils.
ECU and coils/injectors are grounded to negative terminal on battery. Engine is grounded with a thick cable to both battery and chassis.
ECU gets 12V positive from a main relay near battery.

Updated firmware a month or so ago.
Latest TS.
Loses com. with Console also.

Will try without alternator belt on and ground the ECU to engine next.

Any other suggestions?

PC/laptop connection? Laptop charger? Try running without charger (with only ECU connected over USB).

Dron_Gus wrote: ↑

Tue Apr 11, 2023 8:41 am

PC/laptop connection? Laptop charger? Try running without charger (with only ECU connected over USB).

Tried with and without charger, and with 3 different USB cables with the same results unfortunately. Will try with a different PC today if I have time.

Thanks for your suggestion

I had disconnections when charger and ecu were connected at the same time.
Laptop has dead battery so I start using cheap USB isolator (ADUM3160 based) from Aliexpress. Now I can have both charger and ECU connected to laptop, and get not disconnection when cranking.

that's a nice hint! Hadn't thought of that a while ago, when got disconnections trying to connect to my frankenstein)