O/2 Sensor location

Ed Wright · 11-17-2012, 09:51 PM

Art, is the coolant temp the same? Anytime I have had one pop & bang it has looked lean. If the engine is cooler I would guess it's a tad lean. My stuff always goes down the track quickest richer than the dyno liked. If your problem is at lower temps you might try adding a little fuel in your air/fuel coolant temp correction table, at the temp you are seeing first pass. That's providing you don't warm
It up to the same temp it runs at the rest of the day.

art leong · 11-17-2012, 10:10 PM

Quote:

Originally Posted by Ed Wright

Art, is the coolant temp the same? Anytime I have had one pop & bang it has looked lean. If the engine is cooler I would guess it's a tad lean. My stuff always goes down the track quickest richer than the dyno liked. If your problem is at lower temps you might try adding a little fuel in your air/fuel coolant temp correction table, at the temp you are seeing first pass. That's providing you don't warm
It up to the same temp it runs at the rest of the day.

Coolant was actually 1 degree (centigrade) hotter (67 to 66) on the first run, than the second. And equal in latter runs.
I was wondering if in starting and warmup I'm fouling the plugs. And it takes a run to clean them?
I've got to work on the start fuel map, it does not like to start cold. pops out the throttlebodies like mad.

Ed Wright · 11-17-2012, 11:08 PM

Art, I would warm it up, then pull the plugs. They should be pretty much white. If they are black, you found it. If you can slip a muffler on it, or an extension about two feet long, you can idle it & drive it up and down the return road to find where it is so rich. Try to make it run 14-1 to 14.7-1 air/fuel at idle and all part throttle areas of the map. You can get a look at the decelloration a/f if you leave the logger on as you slow down. I think your probably cleaning the plugs up on the first pass. I'm surprised at how many black spark plugs I see guys pull out after warming them up. I hear over- rich cars driving around the pits all the time. Maybe they are trying to tune that part with open collectors?

11-17-2012, 09:51 PM	#1
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: O/2 Sensor location Art, is the coolant temp the same? Anytime I have had one pop & bang it has looked lean. If the engine is cooler I would guess it's a tad lean. My stuff always goes down the track quickest richer than the dyno liked. If your problem is at lower temps you might try adding a little fuel in your air/fuel coolant temp correction table, at the temp you are seeing first pass. That's providing you don't warm It up to the same temp it runs at the rest of the day. __________________ Ed Wright 4156 SS/JA

11-17-2012, 11:08 PM	#3
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: O/2 Sensor location Art, I would warm it up, then pull the plugs. They should be pretty much white. If they are black, you found it. If you can slip a muffler on it, or an extension about two feet long, you can idle it & drive it up and down the return road to find where it is so rich. Try to make it run 14-1 to 14.7-1 air/fuel at idle and all part throttle areas of the map. You can get a look at the decelloration a/f if you leave the logger on as you slow down. I think your probably cleaning the plugs up on the first pass. I'm surprised at how many black spark plugs I see guys pull out after warming them up. I hear over- rich cars driving around the pits all the time. Maybe they are trying to tune that part with open collectors? __________________ Ed Wright 4156 SS/JA