MSefi.com read only forum (Jan.15,2018)

hey all, been wrecking my brains here..
setup as following, MS2 on a v3.0 board
now.. everyting works fine on the stim for starters (yay)
as soon as i plug it into the vehicle, no go... cant even connect with Tuner studio,
i have 12v feed, clean grounds (that i've double checked), and 5v coming from the 5v line
the fuel pump turns on, iac opens up...
what on earth is goin on??

Test MegaSquirt on car for short circuit, you must. To check for a short in the Megasquirt PCB, power up the Megasquirt on the car and check the following points for voltage with a multimeter.

You should find the same voltage as the battery voltage on the following points: S12, S12C, the center legs of Q9 and Q12, the left (non-banded) end of D3, the left leg of U5, and the left (banded) end of D9.

You should have 5 volts at the following points: S5, the two +5V holes in the proto area, the right (non-banded) end of D9, the right leg of U5, the left (banded) end of D19, and pins 1, 20, and 31 of the CPU.

Let me know where correct voltages you find, and where voltage not right is.

hey, have done the tests as described... all checks out ok...
i have noticed that the fuel pump will cycle on, stay on for 5 seconds then turn off...
ALSO... with the crank angle sensor wiring, i have the diy autotune loom which supplies the 5v refence, according to the manual for the motor, originally the CAS has a 12v feed, would this cause any issues? ( currently i am using the 5v reference)

is there any way to test the MS2 on the bench without the stim, ie just a 12v feed, or does it need the sensor inputs for start up?

Stop trying Yoda grammar in my posts, I will.

Yes, you can run it on a bench with just a 12 volt power supply. Naturally, this won't let you check the sensor inputs.

Whether using VREF to power your sensor is OK depends on (1) whether your sensor works on 5 volts (some do, some don't), and (2) how much current it draws.

ok, have tried powering with just 12v on bench.. cannot connect with Tunerstudio, when i apply power (12v dc nom.) all three leds flash and that is all... ARGH

well.... damn.. own mistake... i kept changing the usb port depending upon being out in the shed, or on the bench with the stim...
and ofcourse the adapter/laptop didnt recognise the port. now all is ok

and for the CAS i ended up having to use a pullup resistor from the 5v refence to the signal wire now all is ok

cheers for the help master jedi Cramer appreciated much is was