legacycentral bbs

I just bought a new battery for the car since that old one was very weak. I had the old one out for a few hours and when i put the new one in the car started fine but acted strange. The AFRs are very lean when driving around town, low power and then when in boost afrs return to normal and feels fine. when in boost i am getting new afrs like ~12.6, before I as maxing out the injector and getting ~10.8. My idle is also affected and begins to jump up and down the rpms roaming for a idle. between 400-800.
whats weird is that I feel as it the ECU is switching between stock maps and then chipped maps. weird stuff.


is there a possibility the chip is damaged? or does it take a long time for the ecu to learn stuff.
it has been two days.
I have a 91 SS with VF39 Revtronix stage 2, and 440s grey, TMIC.
anyone have a revscan Subaru Select Monitor (SSM1/OBD1) USB Cable?
i think its a vaccuum leak but i didn't touch any ho's.

Without a data cable to see whats going on in the ECU, it's sort of hard to speculate. You know the EvoScan USB cable works with RevScan too... Possibly the ecu got reset, in which case it needs some time to re-learn the fuel maps. Could have an air leak throwing off the MAF... Which version of the chip do you have? I believe it was the stage 2 v2 chip which fixed the bouncing idle issue... if not the rare stage 2 v3 fixes it by increasing the fuel trim limits to +/- 50%.

update on this. I meet up with aaron ASC_UP and got the cable and finally tuned and fixed everything. The oxygen sensor was giving lean afrs and the ecu gave up on the adjusting to fix this. We adjusted the table on revtronix and its ran alot smoother. the table were at -1.5 and we adjusted to 20.1. immediately we ran alot smoother, idle sounded better and driving was back to normal.

If the O2 sensor wasn't fixed and still remains a problem, the fuel trim tables will re-learn the bad values again, overriding what you manually typed in...

the oxygen sensor is fine and the afrs are great. But i need help connecting revscan to the chip. I got the drivers and program from revtronix and I don't understand how to connect.

crashnburn wrote: But i need help connecting revscan to the chip. I got the drivers and program from revtronix and I don't understand how to connect.

Seems a lot have this 'issue'. http://bbs.legacycentral.org/viewtopic.php?f=19&t=43238

sweet got it to work. thanks