View Single Post
Old 10-18-2010, 08:22 PM   #244 (permalink)
ShadeTreeMech
Basjoos Wannabe
 
ShadeTreeMech's Avatar
 
Join Date: Apr 2009
Location: Arkansas
Posts: 870

The Van - '97 Mercury Villager gs
90 day: 19.8 mpg (US)

Lyle the Kindly Viking - '99 Volvo V70
90 day: 25.82 mpg (US)
Thanks: 174
Thanked 49 Times in 32 Posts
Quote:
Originally Posted by Nerys View Post
The pinging IS FROM THE E10 I think (not my area of expertise). when I get E0 it stops pinging. (at least it did back then)
pinging is from the gas igniting before the spark plugs light up. This is due to an octane rating lower than needed by the engine. Sometimes fluctuations in engine conditions, such as carbon build up in the combustion chamber or on the pistons, will cause the octane knock (aka pinging)

If the fuel ratio has gotten too lean for some reason, or you got into some crappy gas, this can also be a problem. If one injector is in need of a cleaning, that could lean out a cylinder. Regardless of the cause, pinging is to be avoided. If it gets bad enough, the flame from the preignited gas can burn a hole in a piston. This happened to me on an Isuzu pickup. Luckily I was able to get it repaired for free. But the short term solution is to put in some higher octane fuel until the problem is solved. I usually will go to 89 octane if I have a problem. If you have a partial tank, add 93 octane if you can find it--out here Exxon is the only one who carries it.

I have a homemade fuel injector cleaner recipe if you're interested that usually will fetch an extra 2-3 mpg for the tank I put it in. The ingredients can be bought for less than $10 at any grocery store.
__________________
RIP Maxima 1997-2012


Quote:
Originally Posted by jamesqf View Post
I think you missed the point I was trying to make, which is that it's not rational to do either speed or fuel economy mods for economic reasons. You do it as a form of recreation, for the fun and for the challenge.