general questions....bank 1 leaner than 2?
08-23-2009, 10:55 PM
#1
general questions....bank 1 leaner than 2?
I've been logging my truck so much that I've noticing trends as I'm trying to figure out why my truck keeps detonating a lot at WOT.
1) In normal driving and WOT, bank 1 is always leaner than bank 2 (at WOT bank 1 is usually .30 mV lower and on normal driving LTFTs for bank 1 are always usually a little more positive i.e. 1.6% versus .8% for bank 2). Is this normal or is something going on here?
2)I've noticed that at WOT my truck only detonates over ~3900-4000 rpms. If I am WOT below that it does not give any KR and does a nice 24 degrees of timing. But, once I pass 3900 rpms or so, it will spike up a couple degrees of KR and then go to 6-8 degrees of KR.
Today I replaced all my spark plugs, I did find one from bank 1 on inspection that had the porcelain cracked (dont know which cylinder it came out of). I put all new TR55s in and I also put the stock wires back on (in place of MSDs) and there was no change with the detonation.
Tomorrow I will be receiving a basically new set of high output LQ9 spark coils which will be replacing my 152k mile stock 00 ones. I'm systematically trying to rule out things...I've replaced the intake and TB gaskets and I put in new spark plugs. If the coils don't do the trick, I'm no sure what I should look to next. Is it possible something is up with my injectors? They looked fine when I had the intake off. I just think it's odd that my detonation always begins at the same RPM. Makes me think it's some sort of tuning issue.
I also wanted to add, on the spark plugs I pulled, I "read them" with some help of some online articles and they all looked great.
1) In normal driving and WOT, bank 1 is always leaner than bank 2 (at WOT bank 1 is usually .30 mV lower and on normal driving LTFTs for bank 1 are always usually a little more positive i.e. 1.6% versus .8% for bank 2). Is this normal or is something going on here?
2)I've noticed that at WOT my truck only detonates over ~3900-4000 rpms. If I am WOT below that it does not give any KR and does a nice 24 degrees of timing. But, once I pass 3900 rpms or so, it will spike up a couple degrees of KR and then go to 6-8 degrees of KR.
Today I replaced all my spark plugs, I did find one from bank 1 on inspection that had the porcelain cracked (dont know which cylinder it came out of). I put all new TR55s in and I also put the stock wires back on (in place of MSDs) and there was no change with the detonation.
Tomorrow I will be receiving a basically new set of high output LQ9 spark coils which will be replacing my 152k mile stock 00 ones. I'm systematically trying to rule out things...I've replaced the intake and TB gaskets and I put in new spark plugs. If the coils don't do the trick, I'm no sure what I should look to next. Is it possible something is up with my injectors? They looked fine when I had the intake off. I just think it's odd that my detonation always begins at the same RPM. Makes me think it's some sort of tuning issue.
I also wanted to add, on the spark plugs I pulled, I "read them" with some help of some online articles and they all looked great.
Last edited by GMCtrk; 08-23-2009 at 11:15 PM.
