B1 always leaner than B2 @ wot?
09-02-2005, 05:52 PM
#1
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B1 always leaner than B2 @ wot? 02 B1 always reads lower than b2 and I think it is the source of my kr problems. All my wot runs B1 measures anywhere from 20 to 100 mv leaner, Ive thought for a while I might have a small exhaust leak could this be the problem. Could it be the sensor even though it is very consistent and seems to be reading accurately?
09-03-2005, 11:32 AM
#4
Using your O2 values to tune WOT will not be consistent. You should be using a wideband for this.
Sure it could be an exhaust leak before your O2's. It would allow unmetered oxygen into the exhaust stream, making the O2 think you're running lean, so the PCM adds more fuel to compensate.
If you're running lean on bank 1 (driver side), your fuel trims for bank 1 should reflect that as well by being much more positive than bank 2. Try swapping the O2's between banks, reset your fuel trims, and give it about 50 miles of driving time to re-learn. See if the problem follows the O2. If it it stays lean on bank 1, then the O2's should be ok. If not, replace the O2 sensor which was originally on bank 1 and re-test.
You could do the same swap with the injectors, although it's harder to track down since our fueling is per bank not per cylinder.
Sure it could be an exhaust leak before your O2's. It would allow unmetered oxygen into the exhaust stream, making the O2 think you're running lean, so the PCM adds more fuel to compensate.
If you're running lean on bank 1 (driver side), your fuel trims for bank 1 should reflect that as well by being much more positive than bank 2. Try swapping the O2's between banks, reset your fuel trims, and give it about 50 miles of driving time to re-learn. See if the problem follows the O2. If it it stays lean on bank 1, then the O2's should be ok. If not, replace the O2 sensor which was originally on bank 1 and re-test.
You could do the same swap with the injectors, although it's harder to track down since our fueling is per bank not per cylinder.
09-03-2005, 06:54 PM
#6
I have also found that at WOT the Ltrms are multipliers for the PE. If your Ltrms are B1=+5 and B2=+8 at WOT then the O2s will be lower/leaner on B2. The O2s sensor location and condition also play a role, but if they are in good shape, O2 sensor location and Ltrm readings are likely creating the off set. This is why it is so important to have the Ltrms at zero when you go WOT. I hope this helps.
09-04-2005, 05:40 PM
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swapped 02's today and bank 1 stayed leaner, ran a full can of carb cleaner through the top half and also dumped in alot of injector cleaner. I think it did something sent everything +4 lean corrected tune and Ive still got the same problem. Im almost positive it is the injectors I bought these 31lbers used off someone and god knows what they have been through. Below is a pic of the problem. You can see even under part throttle that side tends to run leaner.
I dont think its an exhaust leak because its causing kr.
Any ideas on how to narrow down which injector it is or if its possible to test with an ohm meter.
I dont think its an exhaust leak because its causing kr.
Any ideas on how to narrow down which injector it is or if its possible to test with an ohm meter.
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09-04-2005, 07:58 PM
#9
I don't know of any easy ways to test injectors - hopefully someone else can jump in here. You could swap injectors bank-to-bank to confirm it's at least one of the injectors currently in bank 1. If the problem moves to bank 2, I suppose you could try to move them back one at a time to see if you can narrow down which injector(s) are causing the problem.
But if they're questionable, it may be more beneficial to just buy flow-matched injectors. Did you re-calibrate your IFR table for these injectors?
It looks like your injector pulse widths are basically even on both banks. I would think if the O2's reporting lean on bank 1, that your IPW on bank 1 would be higher than bank 2. Hopefully someone else will chime in here.
But if they're questionable, it may be more beneficial to just buy flow-matched injectors. Did you re-calibrate your IFR table for these injectors?
It looks like your injector pulse widths are basically even on both banks. I would think if the O2's reporting lean on bank 1, that your IPW on bank 1 would be higher than bank 2. Hopefully someone else will chime in here.
09-04-2005, 08:06 PM
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Originally Posted by JimMueller
But if they're questionable, it may be more beneficial to just buy flow-matched injectors. Did you re-calibrate your IFR table for these injectors?
I have tweaked this thing till Im about to puke and its got to be the injectors, it seems to be getting worse also. Im gonna run inj cleaner for the next month, then it looks like Ill have to swap em out on that side if I cant narrow it down.
There has to be a margin of mv that can be measured at the injector at idle that should give some sort of indication like one being lower than the others.
Has anyone ever done this?
