Thanks to messages sometime ago on brickboard I put replacment on this little thermostat on the to-do list since it was original. The part is fairly inexpensive and I included it with my last eeuroparts.com order. I've also purchased a crank position sensor on the same reasoning, but haven't installed that one yet.

Today while doing some regular maintenance I removed the air box to replace the thermostat. What do you know, the original had failed completely and apparently the car was always running with pre-heated air. After fixing everything up (and sandblasting and powdercoating the top hold down bracket) I was surprised by the improvement in how the car runs. Both acceleration and idle seem greatly improved. This surprised me because I wasn't expecting a noticeable change.

Hopefully I will see some fuel economy upside. The past four tanks of fuel have clocked in almost exactly at 23 MPG with our mix of driving. That seemed reasonable as the driving is mostly moderate speed back road sort of stuff with 10-15 mile trips being the norm, each trip including 5-10 full stops. Having a baseline I am very curious to see what happens on the next several tank fulls.

Hopefully the AMM hasn't been terminally stressed!

John