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View Full Version : Reprogramming Digital ECM



plawler
05-08-2001, 11:49 AM
I am in the process of rebuilding my 1997 promax. I would like to be able to reprogram the ECM to adjust the rev limiter and injector duty cycles. Does anyone know of the tools and methods required?

espen
05-08-2001, 05:22 PM
If the ecm has a chip you can take out ,you can get a e-prom reader and put the eprom into and download all info on the chip .Software for wiewing this numbers wisualy to see
patterns and look for maps are available. When you think you have found the fuel map you can put in some Zeros and burn a chip put it in your ecm and go for a ride or make a bench with inputs that simulates the engine.Have heard people burning 400chips before they where satisfyed .When wathing the rpm and
trottle possition or manifold pressure you can see where the fuel shuts off.This way and by studying the ecms features you can reverse enginere the chip and find the adresses and what they do .Some clever guys make editors
from this information and make it easy to change calibration.
You can invest in a e-prom emulator that puts out a trace on the pc screen from where the data is taken from during
running ,by pushing buttons on the pc you can add numbers to where that info is taken from ,but would not tell you what you are increasing.
if its a EE-prom you probably have to dig it out and unsolder.You could allso go to Merc or the manufactorer of the ecu you have, and beg for calibration software but I dont think they will sell it to you unless you buy 300 ecms .Or maybe ask rapair do make a new chip for you ,he has allready done this tour .....

TTriton
05-08-2001, 09:25 PM
Belive me its worth it. I've never done this with a Merc but when I installed a DFI computer in my Buick Grand National I spend days playing with it and never got it to run right. Then I paid someone to do it and all the problems when away. Unless you plan to do it everyday its just not worth taking in the learning curve to burn one chip. Just my opinion.

MERCMAN
05-09-2001, 05:21 PM
if your motor is a 225 i have a customer that has one already modified with no rev limiter and a real nice fuel curve for the modifications. what number is on your ecu?

Frequent Flyer
05-09-2001, 08:33 PM
I still have the project laser ECU for sale which has no rev limiter and a fuel curve that was modelled off of Tony Brucato's ECU for his modified promax + 20% more fuel in the midrange.
Only $500F + S&H
soliman@optonline.net