Fuel trims goto 0.0% @ WOT, 16-18 deg timing max
08-21-2003, 01:46 PM
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Fuel trims goto 0.0% @ WOT, 16-18 deg timing max Ive been having tuning issues on my ls1swapped older car.
Cruising around ive got fuel trims in the -10% to 0.0% range most of the time when driving.
The moment i hit wot, fuel trims goto 0.0% and never change, almost like they dissapear. Also my timing advance stays in the 16-18 degree range through the rpm range @ WOT. I have no knock retard at all now.
I think im leaving a ton of power on the table with the crap thats going on in the computer...any ideas?
Car is a forged bottom end, cnc heads (290 cfm), ls6 intake, headers, bolt-ons, 227/230 @ 114 TR cam.
Cruising around ive got fuel trims in the -10% to 0.0% range most of the time when driving.
The moment i hit wot, fuel trims goto 0.0% and never change, almost like they dissapear. Also my timing advance stays in the 16-18 degree range through the rpm range @ WOT. I have no knock retard at all now.
I think im leaving a ton of power on the table with the crap thats going on in the computer...any ideas?
Car is a forged bottom end, cnc heads (290 cfm), ls6 intake, headers, bolt-ons, 227/230 @ 114 TR cam.
08-21-2003, 04:41 PM
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Re: Fuel trims goto 0.0% @ WOT, 16-18 deg timing max Yep, you want the fuel trims to lock in at 0% at WOT. If they are positive it means fuel is being added which may not need to be.
Your timing sounds really low. What year computer do you have? '01+ have low timing from the factory but, not that low. Also, if it's real hot out where you're at that could be causing timing to be pulled.
Do you have a OBDII diagnostics port hooked up? If so you could get LS1edit for your car and take care of the timing and anything else you wanted to change.
Raising the timing up to around 27-28 will make a pretty good SOTP difference.
Your timing sounds really low. What year computer do you have? '01+ have low timing from the factory but, not that low. Also, if it's real hot out where you're at that could be causing timing to be pulled.
Do you have a OBDII diagnostics port hooked up? If so you could get LS1edit for your car and take care of the timing and anything else you wanted to change.
Raising the timing up to around 27-28 will make a pretty good SOTP difference.
08-22-2003, 12:01 PM
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Re: Fuel trims goto 0.0% @ WOT, 16-18 deg timing max What is the best way to change the timing for this problem in edit? I am having a similar problem and can not figure out wich table is best to change timing, my ltft read positive. Sorry for butting in on your thread but i can not find a solid answer on this.
08-22-2003, 10:49 PM
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Re: Fuel trims goto 0.0% @ WOT, 16-18 deg timing max I use the high octane table. Just make small changes at a time, and then check the results...I use a-tap.
08-26-2003, 09:50 AM
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Re: Fuel trims goto 0.0% @ WOT, 16-18 deg timing max The Reason for the low timing is you are in the Low octane table, the PCM has seen enough spark knock to enable the low octane table. You may want to make both tables the same or within a few degrees of each other. Your choice.
