Tuesday, September 20, 2011

It runs!

I plugged the Megasquirt 3 into my car, powered it up and didn't get any smoke.  That's a good start!  All of the sensors indicated normally.  Coolant temp, MAP, etc.   Calibrated the throttle idle and WOT positions.

Removed the fuel pump relay and cranked the car to check rpm and synch.  Nothing...

Checking the crank sensor input to the Megasquirt.  Polarity is correct.. looks good.

I connected some more wires inside the Megasquirt case to check the output of the VR conditioner against the input signal.  The VR conditioner has two pots that adjust the trigger level and the hysteresis.  If the trigger level on R56 is too high it will never trip.
Trigger level and hysteresis.  Picture by DIYautotune.com

After adjusting R56 to the left I tried again and got a nice scope picture.

Yellow is the sensor input and blue is the VR conditioner ouput.  Looks consistent, no noise.  VR signal is only 5v peak-to-peak but this was while cranking.  I'm using 10x probes.

While cranking to get his picture, the motor kept trying to start even though the fuel pump relay was removed.  It was catching on residual fuel.

I re-installed the fuel pump relay, removed some of the crap from the top of the engine and cranked. 

It started... and fell into a high galloping idle.

No comments:

Post a Comment