I'm using the speed density chip created by pudhed from the dsm-ecu group with some slight modifications.

I'm triggering the WI with a negative pulse to the relay from the purge solinoid on the firewall.

The only thing I have to work out is that there's a momentary trigger of my pump when the key is turned to ON. I'm guessing the ECU is running solinoid checks when the key is turned to the ON position, I'm sure that this can be eliminated if I looked into the disassembly a bit more.

When I first started using WI I was using a pressure switch to trigger my WI, I find controlling it via the ECU gives us more flexibility.

Later, Vlad.