Crankshaft & cam rig

It has been a while since I have been able to do anything on this project. After I built the crankshaft rig for the Thunderace, I saw a post on the MicroSquirt forum and realised I’d need to simulate a camshaft sensor input too. Trouble was although I had a camshaft I could use, suspending it between centres and driving it by chain seemed a little OTT. I decided on a wheeled tyre that would run on the circular part of the crank web, and by running at half crank speed, it would do the job. In reality it probably wasn’t the wisest choice, as it took a fair bit of tweaking and I still need to get a one piece O ring. There are three superglued together on the cam wheel.


Crank sensor not in place yet


After spinning up the cam wheel and using the hand held scope, I was getting too much interference to get any real info : (

Next step was to get a 2 channel oscilloscope that would hook into the laptop, as the hand held Velleman was only single channel. A quick peek on eBay and a few weeks later, a 5 channel USB device dropped through the letterbox.

After loading the software, finding another oscilloscope probe and spinning it up, this was the result. Pink is the cam sensor, light blue the crank.


Looking good so far I thought, so I bootloaded the Tooth Analyser code into the MicroSquirt, and opened the Tach Ref software, so that I could see what the MicroSquirt would see, and nothing happened, Disappointed I powered the unit up. Set the ECU code =2 and the LOW BATTERY in red never went away. Checked the connections, checked the MicroSquirt voltage, checked the bootload ground voltage, reloaded the 2.888a embedded code, but still no battery voltage...nothing seems to make it run.
Checked the MicroSquirt website for documentation, and I hope I haven’t got a bootload lockout (it’s a version 1). This is the second time this fault has happened and last time I was clumsily checking the voltages with some new multimeter leads, that were too big and killed a track. I’ll not do the same this time...checked as much as I can, here’s hoping a guru will help me out with a pearl of wisdom.