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Rusty
March 5th, 2009, 04:16 PM
We installed a larger cam and experiencing a serious idle issue. I have to hold the throttle pedal down just to start the car and to keep it running. I am attaching a log file. The AFR wideband was not connected.
Getting strong power at dyno...

Also I am attaching a tune file for anyone that can lend a helping hand with the larger cam idle issue. I really need help fast as going to trask in 9 hours.

Thanks in advance!

5.7ute
March 5th, 2009, 04:25 PM
Lower the VE table in the lower RPM areas. Since your larger cam is idling in a much higher map range you will be overfuelling by a fair amount.

LS1_Dragster
March 5th, 2009, 04:26 PM
No expert here but I'm guessing a vacuum leak. Your MAP numbers are off. A wide band would help show whats really going on too. How big is your cam?

Lee

mr.prick
March 5th, 2009, 04:30 PM
Not to be snide but,
why not log some idle PIDS if your having idle issues?

What is the AFR while idling?

5.7ute
March 5th, 2009, 04:37 PM
No expert here but I'm guessing a vacuum leak. Your MAP numbers are off. A wide band would help show whats really going on too. How big is your cam?

Lee

His cam is 248/254 on a 110lsa.

Rusty
March 5th, 2009, 04:40 PM
I am occassionally getting the random misfire P code. Seems that the random misfires have gone away after chaning the VE table. I still get them sometimes at lower RPMs. I added a bunch of other PIDS. Attached is another log but lower frame rate.

mr.prick
March 5th, 2009, 05:25 PM
Too many channels and too short of a log.

SOMhaveit
March 9th, 2009, 03:36 AM
Looks like a CTS-V VE table. Your IFR is scaled up from stock values approx 3-4%. If I remember correctly, a larger IFR value with the same injector will lean the AFR out. Lowering the VE would call for less fuel and lean the AFR even further.

Without some attempt to do the RAFIG and show Intake air Controller steps and TPS position at idle and AFR commanded and actual, it's not realistic to start making guesses at what to do.