ETHANOL-FREE FUEL
A CountryMark gas station about 5 miles from my house recently started selling their 91 octane ethanol-free fuel. Even though I hate the additional cost (~55 cents/gal more than 87) I'm going to try it out for a little while. A few people on here have made that suggestion and I'm going to follow their advise, at least for a while. If I decide its worth it this will also allow me to run an MP3 ECU, although I'll be locked down to 91 forever...ughhh. I've been averaging a little over 31 mpg lately (while using AC regularly) so I'll keep you posted on any improvements. 1 or 2 mpg improvement may just account for the lack of AC as I head into fall temperatures.
One immediate effect I noticed is a lack of pinging/rattling at low RPMs. I always figured that had something to due with valves or exhaust parts rattling because it never gave knock readings, but it looks like I was wrong. Since high mileage pinging is usually a result of increased compression due to carbon deposits I guess its time for a methane / water injection system to start cleaning the cylinders. I'll probably just pull a washer fluid system from a protg at a junkyard and pick up a misting nozzle to put in the air intake. I'll post up my research on these when I recap the actual install.
The injection system won't do much of anything to clean outside of the compression chamber, so I may look into something else for that like walnut blasting or a fuel additive of some kind. I have no idea what walnut blasting costs. If you have any suggestions for outside the chamber please let me know.