Hey all, Did a little research in the archives and it looks like there's two schools of thought on this: 1. re program Motronic units 2. swap ECU's to aftermarket units. I did a Haltech conversion on my 308 . . used an E6x that will not do sequential EFI on a V8 . . .the E11 will. What is the main reason no one has gone down this path? Reliability? I was impressed at the reasonable cost it seems the Motronic units can be repaired and it looks like you guys have the programming figured out. I'm assuming the 348 (both 2.5 and 2.7) is full sequential EFI . .. is it direct fire ignition also? Thanks for sharing your experience, Sean
348's use a wasted spark ignition firing setup. The OEM Motronic 2.7 units are outstanding. For one thing, they have built in diagnostics for your engine peripheral systems like O2s, MAFs, phase sensor, fuel vapor recovery, etc. You lose all of that diagnostic capability with the aftermarket ECUs. For another thing, the Motronic 2.5 and 2.7 ECUs have watchdog timers that prevent firmware and programming errors for lasting longer than a fraction of a second. An analogy would be a Microsoft Windows watchdog that never let a "blue screen of death" occur for longer than a milisecond before a full reboot was executed and complete. Well, you've got that watchdog with the Motronic units! You lose that watchdog timer with the aftermarket ECUs. Do you really want to use an engine computer that will allow an error condition to go on forever, or even for many seconds, while you are revving your engine up to or past redline?! With the aftermarket ECUs, my understanding is that you are gambling your engine that they never get an error.
And we now have complete programability/control over these units yes? A little geekiness perhaps required from what I was seeing on the lookup tables . .. hex addresses & values? What's the total $$$ outlay to start changing things in the chip? Maybe the guys are doing it so reasonable out there it's not worth messing with? Also FWIW my first E6x had some glitch where it would shut the engine down during "some condition" . .. was never when the engine was hot . . . just warm . .. the Haltech rep (direct conversation not reseller) said the reason for this was this "watchdog" and the new firmware reboots so it shouldn't shut the engine down . .. don't know how true this is but what I was told. Thanks, Sean
The 2.7 motronics are awesome. What you don't have is conrtol over the crappy wires that connect to it. If so inclined you could rewire it especially since a race car would not need say idle rpm bump for A/C etc... The other problem is sourcing the Bosch connectors for the ECU. All else could be changed to GM weatherpak and with a 2.7 motronic that would be the bomb!
