1990 1G O2 volts diff.

[miragetbo1997cc]

Ive read this over and over again and I would like to remedy the problem.The 02volts on the datalogger vs the actual voltage(viaApexi pen turbo timer)reads off by as much as .06..I've read that it's bad ground,But shouldnt that be able to be fixed?Has anyone with a 90 Had this problem.I even thought it might be the ECU but Dunno.There are Stainless Braids attached front, back ,side ,underside of the engine to try and ground it out.Yes its a Mirage but it suffers from the same fate as a 1g .I log my brother's car(1988 Mirage w/'91 4G63Electronics) and they (o2 volts)were inline .Any Ideas?

 

[1LE]

Dunno, but the jumptronix documentation states that for some unknown reason (even with good grounds) that it might be consistently off by that much from what the ECU read too...

 

[miragetbo1997cc]

Is this why '90 ecus are being swaped for '91-94 Ecus?It just bugged me when I logged a friends car ('92)@ IDRC in Feb and his o2 voltage looked pretty.I was jealous

 

[NOSLO2PT0]

Just go off the logging O2's and ignore the SAFC values. Hell, ignore the o2's altogether, and either use a wideband, or tune via knock/timing method

 

[Turboniam]

Originally posted by NOSLO2PT0
Just go off the logging O2's and ignore the SAFC values. Hell, ignore the o2's altogether, and either use a wideband, or tune via knock/timing method

Dito!!!

 

[miragetbo1997cc]

Its tuned via dynojet ,But its the ever changing climate of Socali thats got me going on this tangent.AEM UEGO(??) anyone using it with good results?.This one place is selling something wideband kinda cheap.Wont name the shop but the owner daily drives a mirage turbo.

 

[STARION]

On my 2.0 mirage, I datalog via TMO, and have come to the conclusion that it will always be .1 less than actual. I.E. the actual maximum voltage that the O2 is seeing is only .9V due to the poor ground situation. Others have told me this and I confirmed it. Go ahead and make your car pig rich, black smoke rich at WOT, do a pull, then have a look at your logs and see if they top what the maximum is that you get. For me, it never showed more than .9V. It's something I am now aware of and have to be careful about when I am looking at the O2 volts for fuel tuning purposes, so I make sure to watch the knock and timing adv. like a hawk.

 

[my_gst95]

Sorry to bring this back from the dead but,

on my 1990, I was worried that my O2's were reading low compared to others (.89-.90) and I changed the fuel pump and the fuel filter and still got the same readings. I leaned it out tuning for knock/timing and i did it enough to where I got 0 knock and timing ending at 21...but O2's were at .85-87. Should I even care about that O2 reading if I get 0 knock anyway?

And if all 90's get a lower reading then normal, would that indicate that my friends 1990 awd whos O2 reads at .93 is really RICH? Sorry if this sounds newbish, I just wanna make sure that I'm tuning my 90 gsx right. It just worries me to see 0 knock, great timing advance..but then a REALLY lean o2 voltage set.

my_gst95

 

[NOSLO2PT0]

Yes. at 25psi on pump gas on my Green, My O2's drop down to about .88V at the top of 4th gear, no knock.

 

[my_gst95]

25psi on pump....im turning "green" with envy

my_gst95

 

[miragetbo1997cc]

Originally posted by STARION
On my 2.0 mirage, I datalog via TMO, and have come to the conclusion that it will always be .1 less than actual. I.E. the actual maximum voltage that the O2 is seeing is only .9V due to the poor ground situation. Others have told me this and I confirmed it. Go ahead and make your car pig rich, black smoke rich at WOT, do a pull, then have a look at your logs and see if they top what the maximum is that you get. For me, it never showed more than .9V. It's something I am now aware of and have to be careful about when I am looking at the O2 volts for fuel tuning purposes, so I make sure to watch the knock and timing adv. like a hawk.

Is there a way to ground it better or is it just a 1990 Mitsubishi fluke?This explains why .71 is good,anything lower than .69 produces knock.If I see .67 on the logger,then knock is present.Always.But only up to 16-19.Timing at 20.