Baffled... Bank2 extremely lean Bank1 normal
#21
TECH Fanatic
Join Date: Mar 2003
Location: La Porte, TX
Posts: 1,839
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by CrazyCarl
Good idea on the fuses. I will check those tonight. I have already tried the stock injectors and stock mapping. The same lean condition was happening.
I need some more ideas here. What else would cause bad fueling to Bank 2?
I need some more ideas here. What else would cause bad fueling to Bank 2?
You may have pinched, or partial cut wire somewhere on the the bank 2 injector harness, or the lead that goes up to it. Check all the wiring that goes to all the injectors. If one if them is broken internally, and not making complete contact then you will get a voltage drop resulting in a weak injector. Do you have a volt-meter. I would check the voltage going to the injectors on bank one and use that as a reference. Then I would check the voltage to each of the injectors on bank two, and find out wich one is not suppling full voltage.
Last edited by WS6snake-eater; 07-21-2005 at 11:06 AM.
#22
TECH Fanatic
Join Date: Mar 2003
Location: La Porte, TX
Posts: 1,839
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
One more thought...Did you do a header install recently? I would make sure that all of the header bolts are tight, and that you have no exhaust leaks before the o2. You should be able to hear the leak, but I have seen cases where the leak was so minor, that you could not hear it over the rumbling of the big *** cam. What headers are you running...You may want to check for leaks were the flange welds up to the primaries.
#23
TECH Addict
iTrader: (10)
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Not to hijack the thread or anything, but I notice an issue with my virtually stock motor where Bank-1 could read -0.8% and Bank-2 would be -3.9%. Anyone know why this would happen on a stock vehicle? Could this just be the same thing he's experiencing...only hightened due to a more radical setup? I just think it is odd to find the Bank-1 fuel trims consistently higher by a percent or two.
#25
TECH Fanatic
Join Date: Mar 2003
Location: La Porte, TX
Posts: 1,839
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I few percent is fine...Hell just the angle of the o2 can throw it off 2-3%. That's why when we tune, we are supposed to use the AVG FT from both banks, and not just rely on one bank or the other. Now if you have fueling differences greater than 8% you may have a problem...I had this occur and it was actually a very small header leak. Fixed it, and they are within 1-2% of each other again.
#26
TECH Addict
iTrader: (10)
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by WS6snake-eater
I few percent is fine...Hell just the angle of the o2 can throw it off 2-3%. That's why when we tune, we are supposed to use the AVG FT from both banks, and not just rely on one bank or the other. Now if you have fueling differences greater than 8% you may have a problem...I had this occur and it was actually a very small header leak. Fixed it, and they are within 1-2% of each other again.
#27
10 Second Club
Thread Starter
iTrader: (5)
Join Date: Aug 2004
Location: Missouri
Posts: 272
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by WS6snake-eater
You may have pinched, or partial cut wire somewhere on the the bank 2 injector harness, or the lead that goes up to it. Check all the wiring that goes to all the injectors. If one if them is broken internally, and not making complete contact then you will get a voltage drop resulting in a weak injector. Do you have a volt-meter. I would check the voltage going to the injectors on bank one and use that as a reference. Then I would check the voltage to each of the injectors on bank two, and find out wich one is not suppling full voltage.
I do have a volt meter. At what point should I check the voltage, with the motor off and ACC on?
I have Kooks LTs that have been on for a year. The narrow band sensors are before the collector in the header and my WB is in the x-pipe. It is not an exhaust leak...
SSpdDmon, I am confident we have separate issues. The FT on my Bank2 is maxed out at +25. It doesn't sound like you are having fueling issues.
#28
TECH Fanatic
Join Date: Mar 2003
Location: La Porte, TX
Posts: 1,839
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
[QUOTE=CrazyCarl]
I do have a volt meter. At what point should I check the voltage, with the motor off and ACC on?
QUOTE]
That's a good question...I'm not sure if it sends out a constant signal or if the voltage is supplied in burst. I would try it with motor off and ACC on first. If you are not getting a signal then that means that the voltage is supplied in bursts and that the engine would need to be running. If I had a volt-meter I would check it on mine, and let you know. You may need to do a little experimenting.
I do have a volt meter. At what point should I check the voltage, with the motor off and ACC on?
QUOTE]
That's a good question...I'm not sure if it sends out a constant signal or if the voltage is supplied in burst. I would try it with motor off and ACC on first. If you are not getting a signal then that means that the voltage is supplied in bursts and that the engine would need to be running. If I had a volt-meter I would check it on mine, and let you know. You may need to do a little experimenting.
#29
10 Second Club
Thread Starter
iTrader: (5)
Join Date: Aug 2004
Location: Missouri
Posts: 272
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
*Update* Last night I borrowed a mini temp gauge. With the motor running I was seeing 400+ degree temps on each of the driver side primaries and 97 degrees on all the passenger side. I started pulling spark plugs and finally the connector to the Bank2 coil pack while the motor was running. NO CHANGE. This whole time the car has been running on the driver side 4 cylinders only.
I am very surprised that it would run at all with very minimal shake etc. I am going to start a new thread on this problem. So the reason why Bank 2 is lean is there is no fuel or spark being delivered to that side!
![EEK !!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_eek2.gif)
#30
10 Second Club
Thread Starter
iTrader: (5)
Join Date: Aug 2004
Location: Missouri
Posts: 272
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Incase people were following this here is a link to the new thread. Thanks for the help!
https://ls1tech.com/forums/pcm-diagnostics-tuning/354461-no-fuel-no-spark-bank2-bank1-normal.html
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
https://ls1tech.com/forums/pcm-diagnostics-tuning/354461-no-fuel-no-spark-bank2-bank1-normal.html