Hello tuning a buddies airboat engine and every time we start it up it's lean (17-18 afr) for the first 10-15 seconds. Then the tone of the engine changes and the afr drops to around 14.7.
I've tried reloading his previous tune and it does the same thing.
The only changes made to the engine are 243 heads and Texas speed 224/224 .600/.600 109 lobe separation.
Any idea what can be causing this? Thanks for any help.
I will post a copy of the tune when I get back to the house.
Have you tuned the VE and MAF for the change in cylinder head and camshaft?
My first guess would be it needs more MAF/VE tuning along with airflow and open loop EQ ratio adjustments to get the fueling under control before closed loop takes over.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
5fdp
I have it in open loop tuning the ve table. We don't run maf's on our airboats. Ve table is all within -5-0. Open loop eq ratio is set to 1.0 across the whole table.
Put open loop tables back to stock and only set cells which are 176F or greater to 1.0. Need the extra fuel in cold starts and run as you are in opebn loop until CL kicks in
Ed M
2004 Vette Coupe, LS2, MN6, Vararam, ARH/CATs, Ti's, 4:10, Trickflow 215, 30# SVO, Vette Doctors Cam, Fast 90/90, DD McLeod, DTE Brace, Hurst shifter, Bilsteins etc. 480/430
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AIR pump is either gone or disabled, right? If still active
then this is a likely culprit.
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