[Leadfoot]

Just some random words:

Daox, nice EGR system.

I have experimented with my stock EGR setup and have found a decrease in mpg and power when increasing EGR levels over their stock value. On the opposite side, my engine started missing badly under high load @ 1500 - 2000 rpm. I thought that too much EGR flow was to blame so I disabled it completely. I did not notice any change in performance of mileage. The actual culprit was weak spark. I installed a hotter coil pack and gapped the plugs to 0.065" which solved the problem until the hot coil pack fried the stock plug wires.

My belief is that in an old 2 valve motor such as mine, the exhaust gas is not getting mixed enough with the fuel and air. On top of that the ignition system is far from optimal. I believe that to have a lot of egr flow and avoid missing, you would need 2 wide gapped spark plugs per cylinder and 2 hot coil packs. Having two spark plugs would decrease burn time and help with flame propagation.