Once again Matt at DIY redefines great customer service. It took him all of 7 minutes to walk me to a solution and point out the error of my ways...

I had the stock tps plugged in. Once you do the variable throtle pos. mod as I have you can't use the simple switched cointacts again.... It seems to load up the voltage to the ECU.

 

just thought I'd add my discovery/situation.
I have a ms1 v3 and it wouldn't connect to megatune using the serial connection to a serial port on my old computer or the usb adaptor on my new one. I had no idea what was on it or if it even worked but I thought i'd try new code. That was it.

Now it connects to megatune p1 and p3. Stangely though, easytherm(used for putting code onto ms) only works when its used on my old computer and the ecu is connected using serial to serial. It DOES NOT work with the usb adapter.

If you want to try updating your code go to the megasquirt thread and click the top one (brains: how to diy megasquirt) and follow the software instructions exactly(scroll down and the instructions come right after the build). The code he provides is the latest hi res code and if you follow the steps he provides exactly it should work. (using a computer with a serial port). Again, easytherm shows code 8020 when trying to reflash using the usb adaptor.

Another note: I had to use the jumper on the board in the boot place, it wouldn't work without that either even though in the stickied software thread it says you don't need it, mine did.