Found out my car (Ford) has lean burn. (?)
 

In browsing on the ford escort forum (feoa.net)
Ford Escort Owners Association
I found a suggestion that my car is equipped with lean burn; cited as LOC (lean on cruise) supposedly from Ford. According to the source, AFR adjusts to 17:1 at high speeds and under low load.
I played with the car on a road trip this weekend and I think this is happening with my car. At very slight, steady increases in throttle, the car will read 47+ mpg and then all of a sudden drop to 35 or so - assuming that's when the engine goes back into closed loop.
Things I'm thinking about at this point:
Will a WAI help keep the car in lean burn?
Can I use the MPGuino to monitor this (I think), or will I need an AFR gauge?
I should definitely hook up my vacuum gauge to help me monitor the pedal, and mark the point where it goes out of lean burn.
Should I make a hand-throttle control, and what type? (Basjoos, HughJimBissel, etc.)

gascort -

Cool beans! Either the MPGuino or the AFR gauge will work. The MPGuino will give you lots more information and takes more time to install. The AFR gauge will only tell you when you are in lean-burn, but will be easier to install. Since you have a 1993, you probably have a narrow-band 02 sensor. You need to make sure the AFR gauge is for narrow-band.

I don't know if a WAI will keep it in lean-burn. I suspect the ECU/PCM doesn't take the air temperature into account for lean-burn.
[EDIT: MetroMPG corrects me below]

CarloSW2

CarloSW2, thanks - I already have an MPGuino so if it's better then good news!!
Also glad to hear that the computer probably doesn't use the IAT for this; at least when I do a WAI it won't likely make economy worse.

Temperature (not sure whether coolant or intake) is a major factor for the Honda Insight's ability to enter lean burn. Many owners do warm air intakes to help it.

Not sure about the Civic VX... Maybe Ben or someone else can help out there.

Anyway: I agree - very cool discovery. I wasn't aware.

Dating back to the CVCC civics, killed off by NOX regulations. Its sad that regulations drive certain technologies from the market.

Many of the early systems in the early to mid seventies didn't need catalytic converters.

Not a criticism of emissions regulations from one who remembers what the air used to smell like in this country in the bad old days.

It Just always seemed to me that the basic design should reduce emissions through efficiency with additional treatment and development from the basic premise of best efficiency.

I wonder where we could be today with the last decade of emissions controls and evolution if lean burn had not been regulated out of existence.

Hope to see HCCI become the standard of the future. That was where lean burn was headed until the rug was pulled out from under the technology.

regards
Mech

Nice find!!!

I would definitely add a wide band O2 sensor. Just to see whats going on.

Like MetroMPG said I'm sure a warm air intake or some way to heat the intake charge will help you a ton.

From my own experience I have found to run in lean burn you need the intake temps to be very warm. It helps atomize today's poor pump fuel with the government built in low VOC fuel regulations.

Good luck on your project!!!

With the lean burn engine in my car, as the temperature drops, I can maintain lean burn to a higher throttle position, i.e. a wider injector pulsewidth as shown on the SuperMID. On a hot summer day it drops out of lean burn at 6.0 usec, but at 25F it will rise to 6.3 usec before dropping out. Since I have a driver adjustable radiator door/grill block on my car, I have the equivalent of a WAI.

Rather than comment speculatively based on what Honda has done with leanburn, perhaps we can figure out what actually has gone into ford's design to see how we can best use that?

Is there any commonly known info about the electronics on this era of Ford?

Nothing involving this that I know of; I know a bit about the programming involving performance from my Mustang, but I know little regarding lean burn.
A bad IAT sensor can/will wreak havoc on a Ford though, so it isn't too out of line to think it might be involved here.
I'm interested in figuring out with my WAI.

I've read on a Ford truck website, that I no longer remember the address of, that some Ford trucks go 17:1 cruising down the highway, they have some term for it like "super highway mode"???