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99 Silverado 5.3 LM7 Rich on both banks
I feel like I have eliminated everything and ran out of ideas
FT at idle sit around -10 total
FT at 2500 RPM around -25 total
-ECT goes from 60°to 210° as the truck warms up and completes a heat cycle no issues there
-MAF brand new Delphi around 5.5
-Both 02 sensors switch from 200 to 900 MV and both react to a rich and lean condition
-Fuel pressure KOEO 55 PSI
-Fuel pressure at idle 48 PSI
-Fuel pressure at 2500 RPM seems to be around 48
holds 48 PSI after 10 minutes
-Injector leak down 5 PSI drop across all 8
-I have also removed the purge valve and vacuum tested it, it was sealed unplugged it while the truck was running and it sealed, removed the purge line as well and still rich condition
- I checked the FPR for a torn diaphragm and no fuel was coming out of it
- Removed the PCV hose
The truck also runs well and doesn’t seem to have any restrictions on the exhaust it picks up speed just fine no actual drivability issues
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