as I am progressing in the build of the cars, I have a couple of questions:

- what is the typical fuel pressure that you guys run? I have a FPR to install, and i need to set an initial pressure.

- can you just leave the O2 sensor not connected? I have no bung on the header, and I am not sure how the ECU will run without the sensor's input

that's all I got for now, but I am sure other questions will crop up as I finish the car.
thanks

 

https://honda-tech.com/zero...90901

Your results may vary...

 

I want to say we dyno'd at 36 psi but found the EGT's too high during my race at LMS that year and ended up around 40-41 psi. Then later w/ the second motor, I believe we dropped back to 38 psi or so. Can the answer be "it varies?" Sorry I don't know anything more than that.

 

thanks for the info guys, what 'bout the O2 sensor?

 

Mine was set on the Dyno w/WBO2. The factory spec has a pretty wide range. I am sure that each engine is going to respond a little differently. Honestly, I think all you can give is a ballpark without going to a dyno or logging with a WBO2 meter.

 

I understand that, but what I meant to ask is this (sorry, I was not being clear):
separate from the fuel tuning, can I run the car without an O2 sensor? I know on later (OBD2) cars, you had to make a bung with some cat material to fool the ECU into the proper fuel tuning. Since this is a OBD0 car, can I just leave the O2 sensor plug empty? I have no place to put an o2 sensor on the car.

I hope I was clearer this time.
thanks

 

If you're planning any sort of engine management manipulation software (Crome, Turboedit, etc...) they all have an option to disable the O2 sensor. If its a straight race car, and you're not messing with the software, leaving the O2 sensor out will lead to a check engine light, but otherwise will not affect the performance of the engine in the 3/4 to wide open throttle area, as the OEM Honda software doesn't look for any O2 sensor input in that area anyways.

A good starting point for your FPR is in the 40-45 psi range.

 

I kinda avoided your second question

I am not totaly sure if you can get away with running without O2 on OBD0 or not. I have run my car with a bad O2 sensor (CEL on) and it ran fine. I only ran it that way long enough to get a new sensor. I don't have any data that says you will be getting the proper AFR without it. I "think" that OBD0 just uses MAP and TPS to get the right lookup table for fuel and the O2 is just a "backup/warning" if anything screws up in the system. Please don't take just my word for it b/c I am not comepletely sure this is right.

Sorry I could not be more helpful.

 

The only thing the ECU should use the 02 sensor for is partial throttle/open loop operation....

WOT it should default to the ECU tables, and not rely on any feedback from the 02 sensor.

 

You do not need the 02 sensor.

And I run my FP really high, but mines a dual point.

 

thank you ya'll.
Pressure starting around 40 to be tuned
No O2 sensor needed.

check.

 

Currently I have a check code in my B20 (CRV) swap in my integra. During the swap the female O2 connector wires came free of the plastic connector piece. I thought I had re-wired them correctly back into the corrresponding pin. I somehow failed on this and have a "mis fire" check code due to a failing O2 sensor. The after affects are retarded timing, poor fuel milage and the engine performs poorly until the 3k rpm range.

Hopefully Catch22 and the rest are correct. I just wanted to share. I know the ECU piggyback ssytems zero out any check engine codes and runs the programed parameters reguardless.

Just wanted to share...provide info etc..

 

thanks for the info Larry. I suspect that your poor performance has a lot to do with the fact that you have an OBD2 car that relies more on O2 sensor(s) (two of them if memory serves) to meter the fuel and minimize emissions.

 

The O2 sensor is a huge part of the picture at anything but 75% to 100% throttle. Anything below that, and the O2 sensor takes care of all the fueling. I'm not surprised that your car is not running well without it.

What generation is your Integra? If its OBD1, and you have not wired up the crank fluctuation sensor (CKF), that would be the source of your "misfire" code.