rb30 na - throttle oxygen and speed sensor

brett_32i · Post by **brett_32i** » Tue Feb 24, 2009 9:40 pm

ok, just got my oxy sensor working (appears you need 12v supplied to it, doh)
im getting a reading of around 1.2 at idle. what should i be aiming for? 1.0?
does higher = richer?

does the throttle switch only control the fuel cut? i cant see any where else it is used in the tables.

I also read in another topic that the speed sensor is required to trigger closed loop or fuel cut??
my rb30 is in a torana, so i dont have access to the speed sensor. am i able to fit a resistor and lock it to a value that will cover all bases, or can i get it removed from the program??

Matt · Post by **Matt** » Tue Feb 24, 2009 9:58 pm

the O2 sensor should fluctuate at idle between 0.2 and 0.8 volts. yes richer is higher (above 14.7:1 stoich ratio). do you see it fluctuate at all

TPS is used for fuel cut/recover but also for determining to use timing maps or the tables. same for enrichment tables etc

The speed signal is a pulsed signal so you will need to hook up a speed sensor of sorts somehow??? thats a tricky one. you could get a circuit to simulate it... contact PLMS developments about that one (www.plmsdevelopments.com) and Pete may have something you can use since i know he does something for engine conversions

brett_32i · Post by **brett_32i** » Wed Feb 25, 2009 7:11 am

yeah, it fluctuates around 1.10 to 1.25.
You stated "yes richer is higher (above 14.7:1 stoich ratio)"

Richer is below 14.7:1. So does higher reading of the O2 indicate higher afr, or a richer mixture (lower afr)

Is the speed sensor necessary. what function does it perform. and could it be removed from the address file.

Thevlguy · Post by **Thevlguy** » Wed Feb 25, 2009 7:20 am

i found you wont get closed loop while the TPS is in idle mode, disconnect the tps and it will start swinging between 0-1v.

Matt · Post by **Matt** » Wed Feb 25, 2009 12:22 pm

sorry i stuffed up there... richer is higher on O2 voltage but yeah below stoich on the AFR side of things

brett_32i · Post by **brett_32i** » Sun Mar 01, 2009 6:24 pm

i just dropped my latency down .25v and dropped the whole fuel table down 10 points.
My o2 sensor is still reading around 1.15??

Is this a massively over rich reading? or only a minute variance to 14.7?can someone tell me that this equals an AFR of x??

I also took around 10 pounds of fuel pressure out and the reading is still the same. It does move, so i know its not a short to ground or 12v. So why cant i get it to read between .5 and .8 where it should be??

Thevlguy · Post by **Thevlguy** » Sun Mar 01, 2009 6:41 pm

just to correct what i said, i was wrong, i reloaded a factory map as i was having major over fuel issues, and now it goes into closed loop at idle.

Matt · Post by **Matt** » Sun Mar 01, 2009 9:47 pm

what is your wideband reading?

that reminds me i've got to get another O2 sensor for the RB30. current one is stuffed and showing around 0.1-0.3 volts randomly

brett_32i · Post by **brett_32i** » Tue Mar 03, 2009 8:15 am

i dont have a wideband yet. (tried a snap-on sniffer, but that read from 10 to 50 afr)

i'll try the other sensor plugged in but in atmosphere and see what reading i get. also ill check the voltage coming from the sensor.

from what i have read, the sensor only outputs between 0 and 1 volt, and i am getting 1.2 volts. could it be a nistune issue, misreading the signal or adding an offset?

Thevlguy · Post by **Thevlguy** » Tue Mar 03, 2009 7:48 pm

brett i had this problem the other day, fuel economy has been bad, the 02 sensor showing 1.1-1.2 volts, i had a koen gas analiser on it and AFRs were in the 10s at idle, ended up reloading a base map and the 02 sensor is fine and its going into closed loop, on full load it goes to 1.2v aswell.

brett_32i · Post by **brett_32i** » Tue Mar 03, 2009 9:21 pm

i could load the base map, but then i would have to resize the injectors and change the latency, which is all i have done so far.

ill try it, but i havent done significant mods, especially none at idle, so i dont know if it will fix it.

did you also have issues running rich every where else in the map?

if this/is was the case, then should you not play with the injector multiplier until it comes good?

brett_32i · Post by **brett_32i** » Wed Mar 04, 2009 1:45 pm

plugged another oxy sensor inin fresh air and it read close enough to 0. so that rules out any offset being applied through dodgy wiring or program.

dropped injector multiplier down to 0 and the car would start but not run. set it to 100, and my oxy sensor still read around 1.2

dropped the fuel map down 10 points, and still 1.2

added 10 degrees to the idle timing, and still 1.2

threw in the base na bin file and car idled fine, still at 1.2.
resized injectors and then it ran rough, and no o2 reading was given. adjusted latency from 500 to 800, fixed idle but o2 returned to 1.2.

the only time i saw it at .99 was when battery voltage was 11.9v. restored battery to 13.4v and back to 1.2 on the 02 reading.

even when i turned the fuel reg down the other day, it made no change to 02??

is the ecu trying to maintain this rich mixture??

as i have no tps or speed sensor, it shouldnt be going into closed loop, and even if it did, should be targeting approx .5 O2.

Thevlguy · Post by **Thevlguy** » Wed Mar 04, 2009 7:04 pm

you have a CTS code, is your CTS plugged in?

are you letting the car warm up?

brett_32i · Post by **brett_32i** » Wed Mar 04, 2009 7:11 pm

whats a cts??

the temperature is showing 82 degrees on the screen dump and i confirmed this with the temp gun.

when unplugged, it runs like a bag of shit and reads either 0 or -50.