Originally Posted by popatim
Did you disconnect the battery to reset the pcm after you installed the new O2?
Yes. This is the 3rd Bonne I have brought back to performance levels. For me, it'* best to let the PCM clear and relearn at many steps. It'* kind of fun to watch the numbers tighten-up and feel the car get lighter and quicker. That'* why I'm so touchy about this rich burn. I knew it was on the rich side when I bought it, but there was some Bob'* O2 sensor in it. I thought putting a new O2 in it was a no brainer to improve it.
The trick to this is finding out how the PCM thinks and where it gets its info. For instance, and this may not be an indicator, if the short term trim has to continually bring down the flow, why wouldn't the consistently positive long term trim be backed down?
I'm going to pull the back plugs. One of the six may show a different burn than the others. There is only one FPR. so the flow through the rail must be balanced in a normal state. Maybe one needs more fuel, so the rest are "flooded". I also got a fuel pressure gauge which says i can measure the FPR and the fuel pump with it. Maybe one of them is sick, and just not dead yet.
The only thing left i can think of would be the coils. I had the battery and alternator tested and they are perfect.
I'll proceed, but I'm hopeful for others ideas or problemsolving routes.
1995 SE ..Green and Rattle Can...234K mi...Bonnie (she'll outlive me)
1998 SSEI .. White ..119K mi...Evey
1996 SSE ..MajTeal..157K mi...4/12- Dealer trade full of Lucas Trans fix