I recently installed a madz28 chip and everything was running fine, and it continued to run fine until after about a half hour. Then it started missing and surging only when i accelerated accompanied by smell of unburned fuel. I stumbled home and put the stock ecu back in and it is still doing the same thing, i will drive it tommarow morning once its cooled down to see if that is a factor. Im going to pull my plugs and wires tommarow to see if my Jet hot LTs fried something. i pray that its not an optispark issue! any other thoughts of what it could be would be appreciated.

also at idle it surges realtively small but very noticable when you touch the throttle.

 

What modifications do you have? If its a stock car or bolt-on only car it is likely something other than the tuning.