Ok, I know what open loop and closed loop air/fuel mixture control is.

I was trying to figure a way to keep the ECU in open loop mode.

Maybe disconnect the left and right bank O2 sensors?


Is there any forseen adverse affects to keeping the engine in open loop mode?


I know you folks with an AFC might have some answers to

 

Will make the car run really rich because the the car is running a cold fuel/ingition program while the car is warm. It might even hurt performance. If you undo one of the 02 sensors, it might trigger a "limp mode" if you 4-gen has one that is. Richer really doesn't mean more power unless your car was running TOO lean to start.

 

You wouldnt want to do this. The car runs in open-loop mode (OLM) when cold and at large throttle openings, somthing like over 70% throttle. Any time you go to WOT, the car is in OLM.

The car runs in CLM at lower throttle openings to maximize fuel economy and minimize emissions.

 

jeff- yeah I know it will run rich. I am looking into something that might cause a lean condition and then limp mode with the ECU. If that was the case I was going to try and ghetto rig it to even out

ben- yeah I know that to.. did not know about the 70% throttle though

I guess I should have been clearer.. oh well thanks for the input..


ben I will let you know the deal on AIM

 

Even if you run what I think you are going to run, this is not the way to rich out the mix.

 

I have a Cartech FMU and SuperCharger.

My car is always in open loop mode. Even warmed up at idle. I have tested this with a ODBII Sensor. This normal for my mods?

I went to get emmissions the other day and they didn't want to even look at the car because my computer was in Open Loop mode.

Luckily I talked them into it, and I passed.

IanS

 

Well it was along the same lines as ben, with the MAF. And since I have no job right now if I put my car's ecu into limp mode I was worried about a cheap way to get it out.

I have decided to hold off and spend more time thinking about it and buying a few parts then after I have some money look at it again.

thanks for your input jeff


ian- from what I have seen from mradi, kev, and a few others even with a SC you should be in closed loop mode.

any ecu codes? might want to check the front o2 sensors??

 

In most cars, entry into closed loop mode is controlled by engine temperature. I once had a Chevrolet that ran fine in open loop mode but had serious problems when in closed loop. As a temporary fix, I bypassed the coolant temperature sensor with a resistor from Radio Shack, so that the ecu detected a signal from a supposedly cold engine and stayed in open loop. I learned this trick from Chevy owners who preferred the richer mixture in open loop mode when running at the track. You might be able to do something like this on a Maxima, if you knew which sensor controlled entry into closed loop mode.

 

thanks I might look into that..

BTW it is the 2 front o2 sensors from what I am reading and engine coolant temp.