I have a '93 pickup w/ the 22RE. Ive been thinking of devising a way to replicate the LC Engineering Pro Tuning Module in order to crudely tune my truck w/o cutting open the air box and turning the "ratchet" wheel. I believe you could change your A/F ratio by altering your output voltage from the O2 sensor to the ECU. Does anybody have any experience with the this? Does anybody know the range of output voltages for the 22RE O2 sensor? Any thoughts as to whether this would work or not? Also, I'm guessing you could also alter the output signal of the AFM and change the A/F ratio that way as well. I know changing the fuel pressure could easily change the A/F ratio but im looking for a electronic way which I believe is easier. Thanks

 

Unless you have a bored out throttle body, very high duration cam, over sized valves, header, and a free flowing exhaust...it's not worth it. All you would accomplish is adding more fuel by monkeying with the O2 signal, but with out the extra air it's pointless...my two cents.

 

o2 sensor output voltage is sensitive. even a lengthening of wire could change readings, so i wouldn't mess with it. if you look at the schematic for the afm, you'll notice a bunch of resistors and potentiometer. adding a pot to that circuit might gain you some control over afr, but if it's running well to begin with, i wouldn't mess with it.

 

I have a bored throttle body, lce header, custom exhaust from a '87 supra turbo, and full oversized intake tube with filter. I believe I need more fuel but im not sure b/c I havent bought my wideband yet. I was just looking for a good way to up the fuel w/o going into the air box. If LCE can figure it out, i want to be able to too!

 

Sounds like you need to go megasquirt then...

http://www.megasquirt.info/

 

Just instal a cheap narrow band meter, and see where you are at. I bet just a few clicks and you will be where you want be.

I instaled one on my freash 22re rebuild. Now I think I am going to pick up another one, and wire it up like a timing light. That way I can use it to tune any vehicle. Once you have the engine tuned it is not needed anymore.

If you want the wide band effect, buy a cheap universal O2 sensor, go to a muffler shop, buy a bung for it, weld it in close the exhaust manifold. wire it up only to the narrow band gauge. Instead of over $200 for a wide band set up you will do the same thing for about $50.

Later

 

There's an idle mixture adjust screw on the AFM.
Look at where the duct leaves the AFM to go to the throttle body and ....

 

And forget the fact that the turbo 22re used the same AFM as the RE and that AFM dealt with 50% more air flow, and did so rather accurately, hmmm.....

 

From what I've heard, those narrowband O2 sensors aren't worth the money. With the cheap O2 sensors on our trucks, the sensor mostly just reads under 14.7 and over 14.7, it just keeps adjusting until it switches back and forth between over and under rapidly.

Moral of the story, NEVER TUNE WITH A NARROWBAND O2 SENSOR!

 

Stryker, Are you tou tuning with any type of AFM gauge, or o2 sensor? The narrow band O2 sensors read at under/over 14.7 because that is optimal fuel efficiency. If it swings under, the ECU knows to give more fuel, if it swings over the ECU knows to give less. With the amount of tuning capability on our ECU's there I no reson to spend the big money for a wide band set up. Now if you spring for a megasquirt then yeah maybe a wide band is good idea. And like I said if you put a dedicated narrow band O2 sensor in, just for the AFM guage, you will not see the swings like you do reading off the ECU.

My 22re is pretty well built, and geared front and rear with fairly short gears. And I am getting between 18-20 mpg. Not to many of these little engines on here are getting that.

My next cheap gauge purchase will be a vacuum guage. They will help you adjust your driving style to get a few more mpg.

Good luck