Im looking for help from the 90-92 guys with TPI SD. I need to know what effects timing and fuel? I'm working with a OBD 1.5 ECU in my beretta (dont laugh) and trying to determine a few things without making any more dyno runs.

Is the spark advance directly tied to a VE table which is calculated from IAT, CTS, and MAP or what combination of the three? Is it tied to a table say RPM vs. MAP and then has another table that modifies the output of that table based on IAT?

Is the injector pulse width or DC tied to a VE table which is calculated from IAT, CTS, and MAP or what combination of the three? Is it tied to a table say RPM vs. MAP and then has another table that modifies the output of that table based on CTS?

Basically I'm looking for a sensor input I can modify that will change spark advance but not change fuel (or change it very little) and another I can use to change fuel but not change spark advance (or change it very little).

I have tables from an OBD II beretta that I can look at as that computer has been hacked but its MAF and not SD.

HELP.

EDIT: Yes, I do have a IROC-Z but its an 89.

 

BUMP

I had tried changing the IAT and it seemed to change both but I would like to know if it changes both the same or not. I also tried changing the MAP but it caused fairly drastic changes and I just didnt have time to mess with it more. The car is now in storage and its hard to figure this out now so please answer me if you have any knowledge on this subject.

 

what is the four letter broadcast code. and the ecm part number? you need both of those to get a definition file for the ecm. If you already have it, why dont you just tune the main spark advance table.

 

I made a tunerpro RT file for reading the datastream and codes but no one has figured out how to flash this ECU. I'll see if I can find those two things for you and get back to you. Thank you for posting. If I could figure out how to flash this thing that would be crazy as right now there are only 3 known tuning options; 5-speed swap and downgrade to OBD I, upgrade to OBD II, and the one that is currently being figured out is piggybacking MSII.

 

tunercat has a definition file listed for a berretta. Might have to go that route.