Low vacuum on rebuilt

2007 CHEVROLET SILVERADO
25 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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LARRY YODER
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it had 249000 miles on it the AFM failed and wasted the cam. I did a total rebuild on the engine. Did a mechanical delete on the AFM installed engine and it started up very easy has 40 psi oil pressure runs smooth had it tuned, but it has no power and I only have fifteen inches of manifold vacuum and the tuner said the fuel trims are thirty percent lean. I did a compression test and I have 195 and 200 psi on all eight cylinders. I replaced the intake gaskets did not help pulled timing cover crank timing mark at twelve cam gear mark at six no one piston at TDC. any ideas?
Thank you
Jun 15, 2017 at 5:11 PM
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STEVE W.
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What method did you use to delete the AFM? Have you reprogrammed the ECM to a non AFM configuration?
Jun 15, 2017 at 10:21 PM
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LARRY YODER
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I did not do the programming I had it done he uploaded the program from my ECM and he deleted the four ECM codes for the AFM solenoids.
Jun 16, 2017 at 3:22 AM
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LARRY YODER
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AFM solenoids I did a full mechanical delete. new cam lifters non AFM valley plate and plugged the oil ports under the valley plate.
Jun 16, 2017 at 3:30 AM
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STEVE W.
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Do you know which timing map is in the programming, It's been a while since I did a defeat but I seem to recall there is a different ignition timing map.
Jun 18, 2017 at 4:27 AM