What is the difference between LTFT banks 1 & 2
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On The Tree
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From: NOVA
What is the difference between LTFT banks 1 & 2 I have been trying to do some tuning, but I get such a big difference between Banks 1 & 2 that I think something is mucked up. Are they supposed to be different or the same, Thanks.
Oh ya, I have the tuning done a little, but at WOT I Am only seeing about 19 degrees of timing advance. This is after a heads cam install. Could anyone give me a reason why this is all I am seeing. Thanks again.
Oh ya, I have the tuning done a little, but at WOT I Am only seeing about 19 degrees of timing advance. This is after a heads cam install. Could anyone give me a reason why this is all I am seeing. Thanks again.
TECH Apprentice
Joined: Aug 2002
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From: Maple Grove MN
Re: What is the difference between LTFT banks 1 & 2 I see a difference in my LTFT banks. My driver side is right on the money and the passenger side is about 15 positive. I have concluded this is because of a leak in the passenger side header. Now I get to take the header off. <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />
Justin <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" />
Justin <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" />
Re: What is the difference between LTFT banks 1 & 2 Having a small difference (less than 6) between the different banks of LTerms is no big deal. A small difference in LTerms can be attributed to differences in O2 sensors, and differences in shape of your exhaust banks.
A large difference between your LTerm Bank 1 and Bank 2 will cause fueling problems, and can be caused by an exhaust leak, bad o2, or intake manifold leak at the head.
About your timing. The 01 and 02 timing table is actually setup to take timing to 19 degrees for high air flows. Most 01 and 02 stock cars will not see 19 degrees, because they do not move that much air. Once you H/C the car though, you have increased the amount of air that enters the engine and hence start to reference timing in the high air flow area of the timing table.
To take your timing higher, you will need either tuning, or a timing device.
Good Luck,
Kevin
A large difference between your LTerm Bank 1 and Bank 2 will cause fueling problems, and can be caused by an exhaust leak, bad o2, or intake manifold leak at the head.
About your timing. The 01 and 02 timing table is actually setup to take timing to 19 degrees for high air flows. Most 01 and 02 stock cars will not see 19 degrees, because they do not move that much air. Once you H/C the car though, you have increased the amount of air that enters the engine and hence start to reference timing in the high air flow area of the timing table.
To take your timing higher, you will need either tuning, or a timing device.
Good Luck,
Kevin
Thread Starter
On The Tree
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From: NOVA
Re: What is the difference between LTFT banks 1 & 2 NOGO, my car is a 98 would this still apply to me....Cause looking over the timing table, it seems I should be seeing 28 degrees. I am seeing a little bit of KR, nothing over a couple degrees and it seems to be sporatic.....Could this be causing it, or should the computer still be giving it the timing.
Thanks....
Well my LTFT bank 2 was usually at least +10 greater than Bank 1. Is that the passenger side, or what. I do have a bad header bolt hole in the drivers side head, I need to get it tapped (it is one of the 2 header bolts in the middle that is missing) Could that be causeing my problem, or do you think it is something with a separate exhaust leaks. I even switched o2's and still get the difference????
Thanks....
Well my LTFT bank 2 was usually at least +10 greater than Bank 1. Is that the passenger side, or what. I do have a bad header bolt hole in the drivers side head, I need to get it tapped (it is one of the 2 header bolts in the middle that is missing) Could that be causeing my problem, or do you think it is something with a separate exhaust leaks. I even switched o2's and still get the difference????
Thread Starter
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From: NOVA
Re: What is the difference between LTFT banks 1 & 2 Yikes.....I just looked into my edit tables, and my low octane tables max out at 19 degrees of timing, I am just wondering if this is what I am running.....WTF is my problem....
I ataped the car before the heads cam install and I was seeing like 27 degrees of timing....This is with the same tank of gas, so I don't know whats happening here....
I ataped the car before the heads cam install and I was seeing like 27 degrees of timing....This is with the same tank of gas, so I don't know whats happening here....
Re: What is the difference between LTFT banks 1 & 2 If you are seeing 19 degrees of timing at WOT with a 98, then odds are that you are on the low-octane table.
Try putting at least 5 gallons of gas into the car and doing another WOT run. By adding gas the car will think that there is now better gas in the car and should take you back to the high octane table. If you are still seeing 19 degrees of timing at WOT, then you are going to have to do a g/cyl calculation to determine where your timing is getting referenced from and go from there.
Oh yeah, a poor injector can cause a big split on the LTerms as well.
Good Luck,
Kevin
Try putting at least 5 gallons of gas into the car and doing another WOT run. By adding gas the car will think that there is now better gas in the car and should take you back to the high octane table. If you are still seeing 19 degrees of timing at WOT, then you are going to have to do a g/cyl calculation to determine where your timing is getting referenced from and go from there.
Oh yeah, a poor injector can cause a big split on the LTerms as well.
Good Luck,
Kevin
Thread Starter
On The Tree
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From: NOVA
Re: What is the difference between LTFT banks 1 & 2 Oh god, don't tell me injector problems....I guess I could swap the injectos to the other side, to see if that is the or a problem.
Is there anyway that my offcenter LTFT's, could be causeing a small degree of Knock Retard, and be causeing my car to run the low octane table <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Is there anyway that my offcenter LTFT's, could be causeing a small degree of Knock Retard, and be causeing my car to run the low octane table <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
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Re: What is the difference between LTFT banks 1 & 2 How bout a bad injector O ring? Any smell of gas under the hood? All the injectors plugged in? Any misfire codes? The injector thing is making more sense then you having a leak after I thought bout it. I read in a book where copper gasket spray can mess up readings too....you didn't happen to use any of that stuff did you?
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Verdad Gallardo Re: What is the difference between LTFT banks 1 & 2 There are a couple things that will cause both a large Lterm split (usually very big like 10-15) and enough KR to kick you to the low octane table.
Intake manifold leaks along the head are not uncommon after a h/c install because the milling of the heads makes the manifold not seat *as well*. Or sometimes the manifold just doesn't fit perfect (like alot of aftermarket lids) Sometimes you have to play with it to get it to seat properly and not leak at the head intake port.
Intake manifold leaks from the manifold not seating properly are usually side specific and will cause both misfires, KR, and large LTerm splits
A crappy injector can also show the same symptoms. One way to check you injectors for proper spray is to pop your fuel rail out and flip it upside-down. Have someone turn the car over and watch the spray pattern of each injector. It makes a mess, but it can be a quick way to spot a **** injector.
Good Luck,
Kevin
Intake manifold leaks along the head are not uncommon after a h/c install because the milling of the heads makes the manifold not seat *as well*. Or sometimes the manifold just doesn't fit perfect (like alot of aftermarket lids) Sometimes you have to play with it to get it to seat properly and not leak at the head intake port.
Intake manifold leaks from the manifold not seating properly are usually side specific and will cause both misfires, KR, and large LTerm splits
A crappy injector can also show the same symptoms. One way to check you injectors for proper spray is to pop your fuel rail out and flip it upside-down. Have someone turn the car over and watch the spray pattern of each injector. It makes a mess, but it can be a quick way to spot a **** injector.
Good Luck,
Kevin
Thread Starter
On The Tree
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From: NOVA
Re: What is the difference between LTFT banks 1 & 2 Ya that makes sense, I am using a new intake, and different milled heads.
There is another thing that crossed my mind. my buddy put the plugwires on the coil packs, is it possible one of them might not be on the whole way???? Or would this cause an SES light, I am getting a misfire light anyway, so this makes me wonder? hmm???
I might need someone with skinny arms to reach in there and check.
<small>[ April 09, 2003, 10:10 AM: Message edited by: TreeGreenZ ]</small>
There is another thing that crossed my mind. my buddy put the plugwires on the coil packs, is it possible one of them might not be on the whole way???? Or would this cause an SES light, I am getting a misfire light anyway, so this makes me wonder? hmm???
I might need someone with skinny arms to reach in there and check.
<small>[ April 09, 2003, 10:10 AM: Message edited by: TreeGreenZ ]</small>
