I have a 1978 GMC Motorhome with a 408 Olds using the TB and ECM (1227747) from a 350 chevy truck I started with DIACOM, simple software to modify the tables and a prom burner, but it was tedious and error prone so I designed a ROM/RAM adapter to let me change settings on the fly.

After the design was finished there were resources left in the PLD so I added capture capability to the device that can read any variable in the ECM.

The software has evolved to a dashboard with mph, rpm, temp, tps, map, advance, retard, injector pulse width, gph, mpg, faults, modes, and fuel consumption. The software logs the blm, spark counts, advance, retard and anything else you want.

Another program scans the log file and builds correction tables and applies them to the fuel and timing tables in the bin file. The device uses Flash memory with sixteen different ROM spaces and one RAM space.

The tuning is beginning to pay off, last year the RV (13K lbs) got 14 MPG from Sacramento to LA.

Unfortunately when the last log file was processed some values in the fuel table exceeded an internal limit and shut off the BLM. Does anyone know what the maximum value is? (213 D5h 83.2% works, 239 EFh 93.3% shuts off the BLM)

To correct the problem I am changing the TB from the one for the 350 with GM 5235206 injectors (55lbs/hr) to one from a 454 with GM 5235231 injectors (90lbs/hr) and I need to adjust the fuel table. Does anyone know the formula for converting the fuel table. If injector delay is included in the table it needs to be subtracted before the values can be scaled. Does anyone know the delay time
for the injectors?

If the rom/ram/acquisition adapter were turned into product to rapidly tune engines any idea how much it would be worth? I could have used something like it when I started the RV project. Seventy thousand miles at 7mpg is a lot of cash.

 

I don't know crap about crap, and this link could be crap for your problem but thought it was very intresting, Found the link in a mods sig here.

http://www.dynamicefi.com