If it's a consistent error in that the ECU is switching back due to the O2 sensor reading, then you should be able to override it in one of three ways:

Simply offset the voltage reading by adding a resistor in series (if lower voltage means leaner)

Offset the voltage by splicing in a resistor in parallel (if higher voltage means leaner)

Or run the O2 sensor through a linear amplifier with the proper offset used to move the voltage up or down as necessary.

By doing that you would basically be able to make sure that the ECU receives a signal that keeps it from seeing a "rich" condition by a certain offset. So theoretically if you are running at 12.5:1 and the ECU keeps trying to get back to 14:1... then you need to put in a 1.5:1 offset in the signal.

Additionally if there is something other than the ECU using your O2 signal, you should be able to do a splice appropriately such that only the ECU gets the modified signal.

Make sense? I can do the mathematics and circuits to achieve this if you need it. Just let me know.

This is all of course assuming you can't find a more standard and less DIY ghetto type workaround.

 

sdhotwn that is exactly what im lookin for but i dont know all the electronics and math to do it. plus i believe that the lancer has 2 oxygen sensors so it might be hard. but if you know how i can fool the ecu by given it the reading it wants just let me know what i need and what to do and i will try it out

 

so what if you were to put in a mil eliminator when you put on headers or something like that so the CEL light is not on? Or when you refer to the o2 sensor do you mean the first one?

 

I dunno if the resistor idea would work without causing undesirable side effects. It may cause lumpy idle or stalling. Anyway, if you're looking to monitor any AFR other than stoiometric, you're really going to want a wideband. Narrowbands tend to only read stoich correctly and everything else just seems like "too lean" or "too rich" rather than 16.6:1 or 12.1:1.

 

yea i think if you made something that told the computer that the o2 sensor was always reading 14.7 then it would think everything is fine, and you could add more air with the afc and it would add more fuel and then check the sensor to see if it put in the right amount of fuel and it would read 14.7 and the computer would think all is fine. and i do have a wide band o2 also so i could monitor the air fuel ration seperatly

 

The computer may try and run at something other than 14.7 a lot of the time...

All I would need is what voltage the o2 sensor puts out at 14.7 mixture.. if you give me that I can get you something to try that will produce that voltage. As long as you have the wideband and can make sure that it and the AFC are doing the right thing... then you should be safe.

 

I'm running a AFC with a motec wideband for the last week, and at WOT want % I add or take away, is reflected in the reading of the wideband, crusing on the highway the ECU does adjust to run stoich. different ECU loop at WOT.

 

sdhotwn= the ecu does try to go to 12.5 on wide open throttle it just never makes it so your right it doesnt try to get 14.7 all the time. and andy i didnt have all my o2 sensor and afc before i got turbo like you so i dont know if the afc worked better with out turbo like your sayin. but still with hobie still having the same problem with stand alone it doesnt give ya much hope with the lancer fuel problem.

 

Nah, the hope and ability to fix the problem are in the setup I'm sure. The knowledge just isn't in my head. I have to admit that after only 6 months of driving with the EMS I'm far from a master at tuning it (though I do feel much more comfortable messing with it now that I have the UEGO to measure my results). Once my Defi Link gauges get here from Gruppe-S and I find the time to install them I should be able to iron out whether or not it's a fuel pressure issue. It's entirely possible it's just the mapping on the tuning end. I guess I'll just have to see.

 

I found out this weekend that doing what we were talking about is pretty common practice with turbo's. Usually people refer to the device as a "voltage clamp" All it does is make sure that the computer only sees 14.7 and that's it... I'll look in to it more and keep you up to date!

Steve

 

I'm just curious if these problems are only coming about to those making their own custom turbo setups? Do these things also happen a lot with the RRM setup? Also, thanks for the information, the education, and good luck solving your problems.

 

road races kit is goign to have a lot less 'problems' per se, but regardless problems can occur, if done correctly, the biggest problem with rrm's kit is that you have boost spiking and maybe leaning out a little, which really isnt THAT big of a deal

 

Every type of turbo has had some type of problem so far. Both kits and custom.

Spiking and leaning out are both big deals. If you spike and you fuel system is already stressed you WILL be very lean for however long, potentially causing knocking or just extreme heat which can cause piston, valve, injector or spark plug failure.

 

i just find it odd that certain people using RRM's turbo kit run into problems, while others have no trouble, its hard to decipher what exactly IS the problem most of the time

 

Either the kit is pushing a boundary it shouldn't be (the boost spike/fuel flow capacity thing could be it) or the failing kits were improperly abused or installed.

...or both.