Problems with wide band readings

comish71 · Post by **comish71** » Sat Feb 05, 2011 11:16 am

Hey guys, I'm new to the site. I did some searching and tried changes based on the posts, but no luck.

My a/f ratio does not read properly. It is reading steady at 16.4 at idle, and with revving.

I checked all parameter settings for units. Its reading in air/fuel, not lambda. Hookup of plx is in d10 (eld), wire coming in from harness is cut so that only signal is from eld.

When I look at voltage from eld on hondata sensor it says 2.66 steady.
When I check the voltage of d10 it fluctuates 3-4V range.

The plx setup is new, not previously installed. The wideband appears to be working as the eld voltage fluctuates, at d10, but the reading for eld on the screen for sensors does not change. Not sure what is wrong.

Thanks Guys.

AREA876 · Post by **AREA876** » Sat Feb 05, 2011 6:05 pm

Try disabling the ELD in Parameters

comish71 · Post by **comish71** » Sat Feb 05, 2011 7:19 pm

I tried with the eld disabled and with it enabled. No difference between the two. Still reading AF 16.4 flatline.

AREA876 · Post by **AREA876** » Sat Feb 05, 2011 7:56 pm

Need more information like what ECU and type of vehicle and post your calibration

comish71 · Post by **comish71** » Sun Feb 06, 2011 5:27 am

Setup

p72 obd1 ecu with s300 in 1990 crx. plx is in d10 slot of hondata and input from car harness is cut. running b20-vtec setup.

calibration included

btw, this is just to get the car running and to get tuned later input is appreciated. you can pm me with any recommendations.

thanks

Luke · Post by **Luke** » Sun Feb 06, 2011 9:16 am

you're running open loop, dude ;)

switch it to closed look and it should run with an AFR of 14.7

best regards Lukas

lowblow · Post by **lowblow** » Sun Feb 06, 2011 9:53 am

SET voltage offset

Luke · Post by **Luke** » Sun Feb 06, 2011 11:59 am

lowblow wrote:SET voltage offset

but only if the reading of the gauge is different from the smanager reading.

best regards Lukas

comish71 · Post by **comish71** » Sun Feb 06, 2011 12:55 pm

OK, so i put it into closed loop. Do I use the wideband for closed loop too? I removed the narrow band sensor as well.

Also what do I set voltage offset to? You can change it to read whatever you want, so how do I know if my wideband is working? Can I set it to 20 AFR with the car cold and off? I remember seeing this with the innovate widebands. Or do I set it to 14.7 once the wideband is in closed loop?

AREA876 · Post by **AREA876** » Sun Feb 06, 2011 2:10 pm

comish71 wrote:OK, so i put it into closed loop. Do I use the wideband for closed loop too? I removed the narrow band sensor as well.

Also what do I set voltage offset to? You can change it to read whatever you want, so how do I know if my wideband is working?

Do you have a wideband guage?, what is it reading?, if so you would use the reading on the guage to correct the voltage offset in s300.

comish71 · Post by **comish71** » Sun Feb 06, 2011 4:27 pm

actually i do not have a wideband gauge, i was going to keep my laptop for tuning purposes. i do have a separate wideband (innovate handheld unit) that i can use to calibrate. i am just hoping that all else equal, the plx is functioning properly. any other suggestions?

comish71 · Post by **comish71** » Fri Feb 18, 2011 3:02 pm

Update.

I hooked up a known functioning wideband (innovate handheld obc 2 scanner and wideband o2 sensor) and it read completely different numbers to the PLX. I adjusted the voltage offset so that it read exactly the same numbers as the innovate. I then varied the rpm's but there was not significant change with the plx whereas the wideband varied significantly with the engine rpms. I think the final adjustment on the voltage turned out to be approx -1.4.

Any thoughts?

AREA876 · Post by **AREA876** » Fri Feb 18, 2011 6:01 pm

Note that if the ELD input (D10) is used then R136 and R138 (US ECUs) may need to be removed.

comish71 · Post by **comish71** » Sat Feb 19, 2011 3:25 pm

are these found in obd 1 ecu's as well. i have a p72.

AREA876 · Post by **AREA876** » Sat Feb 19, 2011 10:02 pm

comish71 wrote:are these found in obd 1 ecu's as well. i have a p72.

If it's a US ECU it's written on the circuit board, R136 R138, you can pull the ECU and check.