PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

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Old Apr 24, 2011 | 02:34 PM
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I'm tuning with EFI Live. I'm going way lean anytime I am opening the throttle. As long as I maintain throttle position AF is good. It only seems to happen when I'm puching the throttle down or tip in. What do I need to change to adjust AFR only at this point. My fuel trims go to 25% and KR is at 10 deg. KR then begins to drop but I'm out of RPM before it returns.
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Old Apr 24, 2011 | 02:43 PM
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First thing you should do is fix your airflow tables.

Are you talking WOT or just part throttle. You using a wideband or narrowband O2s?
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Old Apr 24, 2011 | 04:04 PM
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First. I've used a wideband. The wideband and stock O2,s seem to be within .1 or spot on. It's not my wideband so I'm going off my stock ones now.
Second. It's all the time whether part or full throttle.

Here's the whole story. Years ago, I had ported stock heads and a comp216/220 cam and SLP headers. It was dyno tuned with LS1 edit. But my tuner couldn't seem to be able to get rid of the KR so he just pulled timing out at about 3500rpms. I always thought I could hear spark knock when I gave it throttle but would go away immediatly. Since then, I broke a valvespring and made a mess of things=rebuild.
Now. I have forged bottom end. TFS215 heads. FMS F11 cam. Kooks 13/4 to 17/8 headers. Naturally the car drove like **** and I've tried to modify the same tune with EFILive. My friend allowed me to use his cable and wideband. I still have the cable but not the WB. I really don't know much of what I'm doing. I've put some more fuel in with the Lambda and took some timing out of it. Due to unfortunate situations, I don't have a choice but to drive the car regularly. I need to get this at least drivable.
I know I'm running out of injector on the top end but it's not going lean. Just at 98% duty cycle so I put the limiter at 5500rpm. Should I reload a stock tune and start over or change something else.
All of my mods are as follows:
Lid
Ported stock maf
ported TB
LS6 intake
TFS 215 heads
FMS F11 cam 228/230 .576/.595 114
Kooks headers
hi flow cats
3in to 3.5in flowmaster merge
3.5in all the way to back with a dynomax bullet
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Old Apr 24, 2011 | 04:22 PM
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Originally Posted by mypoorLS1
First. I've used a wideband. The wideband and stock O2,s seem to be within .1 or spot on. It's not my wideband so I'm going off my stock ones now.
Second. It's all the time whether part or full throttle.

Here's the whole story. Years ago, I had ported stock heads and a comp216/220 cam and SLP headers. It was dyno tuned with LS1 edit. But my tuner couldn't seem to be able to get rid of the KR so he just pulled timing out at about 3500rpms. I always thought I could hear spark knock when I gave it throttle but would go away immediatly. Since then, I broke a valvespring and made a mess of things=rebuild.
Now. I have forged bottom end. TFS215 heads. FMS F11 cam. Kooks 13/4 to 17/8 headers. Naturally the car drove like **** and I've tried to modify the same tune with EFILive. My friend allowed me to use his cable and wideband. I still have the cable but not the WB. I really don't know much of what I'm doing. I've put some more fuel in with the Lambda and took some timing out of it. Due to unfortunate situations, I don't have a choice but to drive the car regularly. I need to get this at least drivable.
I know I'm running out of injector on the top end but it's not going lean. Just at 98% duty cycle so I put the limiter at 5500rpm. Should I reload a stock tune and start over or change something else.
All of my mods are as follows:
Lid
Ported stock maf
ported TB
LS6 intake
TFS 215 heads
FMS F11 cam 228/230 .576/.595 114
Kooks headers
hi flow cats
3in to 3.5in flowmaster merge
3.5in all the way to back with a dynomax bullet
At part throttle it doesn't really matter which O2 you use. Widebands tend to help you dial in easier, but the stock narrows are going to determine fuel in closed loop anyway so either way is fine. But you need to use a wideband for WOT. Narrowbands are only really accurate right around 14.7. At high 12s/low 13s afr the wideband is the way to go.

98% IDC means you probably need to get bigger injectors but it doesn't necessarily mean that you are getting ready to go lean. The number is just a calculation. I've tuned cars that were running stock injectors and sometimes push the IDC to 120%, but the fuel was always there. You should start looking for bigger once you get around 80%, but that doesn't mean that it's life or death.

Either way, to get you drivable you need to fix the airflow tables (VE and/or MAF).
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Old Apr 24, 2011 | 05:01 PM
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Thanks alot. I'll get to tune more on Tues. and will log some driving tonight
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