1989 V3500

[Zephyr]

Hey everyone, I've got a 1989 chevy v3500 with a 454, I have a Dynamic EFI Flash II installed and I have a basic tune accomplished, however I feel like I am missing something in the tune. My inexperienced assumption is my spark curve might not be fully ideal for my setup.
My current gripe is overall quite low fuel economy, a range of 4-5mpg, I know the 454 is not a platform that is known for stellar economy, but I feel like I have room for some improvement.
The truck is HEAVY, geared low and has big tires, primarily its use if off of paved roads, but when on the highway the RPMs are pretty high even though its generally kept running at around 55MPH. Recently I added a Gear Vendors Overdrive, but have not yet had the opportunity to road test it and see the effects on fuel economy.
-Gen 4 bbc with TBI
-Original peanut port heads (14092360)
-Howards (CL120225-12) Roller retrofit cam: Lift .510/.527, Duration @ .050: 209/213, Centerline 108.
-Diferentals geared with 5.13s
-TH400 with shift kit
-Houghs torque converter (GM5 xtm-1) stall speed 1500RPM
- Shorty headers, dual exhaust.
-35" tires
-ORD underdrive
-Gearvendors Overdrive
IMG_0776.jpg

Attached is my current BIN. I would be thrilled for some pointers.

[dave w]

Possibly there is a .dat file to share?

[Zephyr]

Dave, this is my most current data log file, I hope its sufficient as I only was driving on back mountain roads.

[dave w]

Dave, this is my most current data log file, I hope its sufficient as I only was driving on back mountain roads.

Using Trimalyzer: https://ecmhack.com/trimalyzer/ it appears the BPC values are causing the engine to run rich. Perhaps BPC Calculator requires an update?

BPC.JPG

Lower VE.jpg

Upper VE.jpg

BPC Caculator.JPG

[dave w]

1999 Vortec 454 Timing Table attached.

Vortec Timing Table.jpg

[Zephyr]

Dave, Thanks for the pointers, Ill make corrections to the BPC, update my spark table to more so reflect what is going on in the one you supplied and see how it works out.