Hi,

i really need help - i don't know what i can do further to solve the problem!
I'm running a 3 bar mapsensor and we used crome - the actual version.
Sorry for my bad english i'm from germany.

Yesterday we trimmed the lambda tables of my car. its a B16A2 engine with JRSC @ 9 PSI. For the second or third time (on different cars) we had the problem that the O2 Trim does not work the way we want it to work!

When running the car at 5psi in non VTEC with about 60 percent of open throttle (so not full throttle) it is regulating an A/F of 14,7. That is really really bad!!!

If i hit full throttle the O2 trim gets disabled immediately!

When i go in VTEC with underpressure (no boost) then it stops regulating the A/F 14.7!

The worst thing is really if i'm running 2500upm-5000upm with pressure (3-7psi / not full throttle) where the O2 trim is on!!!!

Then there is one more thing very strange:
at a RPM of 4300 its not regulating 14.7 anymore, instead the Lambdameter shows that: 14,2 - 14,3 - 14,1 - 13,9 - 14,2 - 14,1 - 14,3 - ........
Why is that?
Usually when the O2 trim is on, the lambdameter shows 14.7 14.6 14.7 14.8 14.7 14.7 14.6 14.7 .............


Please help me, i will be glad about any information and help i can get!

 

pm username...........MTBER he is a crome tuner

 

Hmm... Is there an adjustment in chrome that lets you change the closed loop/open loop switchover point?

I think the stock ECU code switches from closed to open loop at something like... 80% (?) throttle.

I know in Hondata you can change it to something lower like 50% _OR_ by a MAP sensor value like right at the transition from vacuum to boost.

 

Just disable open loop.& the oxygen sensor heater in the options menu.

 

I'm mainly an uberdata user, but for some reason i thought with crome they had the option for closed loop to disable based on solely map signal rather than map + tps. If you can't do that then do what mtber sais and disable closed loop all together. Make sure you tune your part throttle columns though or you will probably be running way rich.

 

Hi,

so the problem will not be solved just by disabling Oxygen Sensor Heater?
I cannot disable closed loop becouse i won't pass smog testing anymore!

I'm trying to use uberdata now, maybe that will be better!?

 

Just try it....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by agratise &raquo;</TD></TR><TR><TD CLASS="quote">Hi,

so the problem will not be solved just by disabling Oxygen Sensor Heater?
I cannot disable closed loop becouse i won't pass smog testing anymore!

I'm trying to use uberdata now, maybe that will be better!?</TD></TR></TABLE>
who cares if you won't pass smog. You can just enable it again when you need to.

 

You can pass smog fine with the O2 disabled - it just requires MUCH more tuning of part throttle/low-load maps. I don't ever let supercharged or high compression cars leave with the O2 enabled, and they all pass emissions.

You may also want to post on the Crome forum on PGMFI - people here are not as knowledgeable about it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blundar &raquo;</TD></TR><TR><TD CLASS="quote">You can pass smog fine with the O2 disabled - it just requires MUCH more tuning of part throttle/low-load maps. I don't ever let supercharged or high compression cars leave with the O2 enabled, and they all pass emissions.

You may also want to post on the Crome forum on PGMFI - people here are not as knowledgeable about it.</TD></TR></TABLE>

I also disable the o2 on 90% of the vehicles I tune.
+1 on the forums.

 

yea in fact most people tune for 15:1 rather than 14.7:1 in the lower vac columns so you should be even better for emmissions.

 

I just say tune it in open loop. Just takes some time, or don't boost part throttle.

 

Hi,

i postet in the pgmfi.org forum also! Not very much answers there! I just finished the RTP Board i hope it will run so i can tune in realtime. That would save me a lot of time!