Droff

So I’m still trying to figure out why it sputters from time to time and when it does it always goes lean 16+ AFR. I just put it in speed density mode to eliminate the MAF and it stills sputtered. I ruled out the O2’s because it does it in open and closed loop. It always goes lean so I’m not focusing on spark too much. I had a throttle low code so I replaced the TPS. The MAP has been replaced also recently. If I’m not right about the MAF let me know. I’m getting most of my ideas from past posts.

The question is what sensors are use in both SD mode and MAF mode. Or what sensors are used in one and not the other. Then I could eliminate some sensors to check. It doesn’t do it all the time but it always seems to idle to the lean side 16+ and then come back to 14.7 half the time. It will run strong under load and then let off and then hit it again it will sputter half of the time I do that. It seems to be just beyond my level of knowledge. Any help or ideas would be appreciated.

Thanks.

Voridaeus

Have you physically checked your fuel pressure or injectors?

Droff

Yes, the first thing I did was check the fuel pressers. I was told it was in spec. It was 45 psi at idle. The injectors are another story. Not quite sure how to “check” them except with a noid light. I still don’t know how the injectors would come and go though. I hope it’s something like that that I could lock in on.

Thanks.

bingo

Just because an injector is getting a signal doesn't mean it is working properly. It could be clogged or trying to fail. Check the resistance on each one with a multi-meter.

Droff

ok. What should they read.

bingo

I don't remember, but it seems like 14-16 ohms. That is what mine were. You could search to make sure.

Dave89IROC

don't rule out spark

lolw/no spark=unburned fuel(+air) in exhaust, and o2s read oxygen(air) only, so, it reads lean

there could be liquid fuel dripping off the sensors,and they will read lean

Droff

Interesting, it started around the time my traction control motor mount broke and the unit was sitting on my headers. I had a TCS light because the wires on the motor melted through and the wires were shorted to the headers. I never found a fuse blown but I wondered if it had any bad effects. Does anyone know if those wires are isolated to the TCS system or could short other systems?