running datamaster my o2 readings from bank 1 to bank 2 always are different, like bank 1 will read around 300 and bank 2 around 500. i tried swapping o2's and it seemed like they changed but nope, they went back to how they were.

car is a 230/236 cam, syty injectors, aeromotive fuel system, edelbrock shorties, stock lower and fully p/p heads done by me.

right now my best guess is it's in the porting job and i have some cylinders running richer/leaner than others. only thing i can think to do is install headers with thermocouples and balance the cylinders.

is there something else i should look into first?

mike

 

Since you are using numbers like 300 and 500mV, I'll assume you are talking about closed loop operation. Each bank of the engine is controlled independantly by its own "loop". There is absolutely no reason for the two banks to be identical in any single data frame. They will each be covering the range of 0xx - 9xxmV independantly. The key is that the average O2 sensor reading over a long period of time is close to 450mV on both banks.

When you go to PE mode, and start to see numbers in the 850-900mV range, you should expect the banks to be within maybe 20mV of each other.

 

any how do you go into PE mode? i'm assuming those are WOT numbers?

i haven't been doing much lately, last datalog was last summer. it's just something that bothers me, before i push the timing i'd like to add the LT4 knock module and make sure the banks are making sense. i just didn't understand why one bank would have consistantly higher o2 readings than the other bank. i'll go look at my datalogs again. maybe i'll get some gas for the car and do another log just to see where its at right now.

 

You could swap injectors to the opposite side and see what that does.

 

Don't swap anything until you truely understand what the numbers mean. Yes, PE is the equivalent of WOT, although the stock tuning will put you into PE (power enrichment) mode at less than WOT, as a function of RPM.

 

Take the data you have and average the banks (like Injuneer said). Then, come back and tell us what you get.

 

how do you propose to average the numbers? look for the lowest and highest or what?

i ordered the knock module, once that comes in i'll do a new datalog and see what things are looking like.

 

You pick 100 sequential datas points, add them up and divide by 100..... that gives you the average. I just put the data table in Excel and let the "AVERAGE" function do the work.

 

What are you trying to accomplish with a new knock module?

 

i added some promags awhile back, just wanna make sure i don't get any false knock off them. i noticed the knock counts raised quite a bit with the addition of the rr's.

anyhow, exel sounds like a great idea, i don't suppose anyone has posted how to trasfer the data in there and do that, have they? maybe a site on it?

i went over some old logs yesterday, unfortunately i haven't done many driving logs due to a bad laptop battery. so i only found one log with 100% throttle readings. in that log my o2's were 40-60 mv different from eachother. usually bank 1 was lower than bank 2. bank 1 read 840-860 and bank 2 was at 900-920.

 

nevermind i did a search and figured the excel question out, i'll have to get a new log and try it.

thing is i have storage on the car, theres a bunch of snow in the drive at my parents and the roads are covered in salt, but we're supposed to have warmer weather this week.