AFR change after ECU swap

raddy · Post by **raddy** » Sun Nov 08, 2009 12:27 am

Hi all
Strange thing happened to me today, I tuned ca18det with nistune ecu, then saved bin file and programmed it into the EPROM for fit to normal ecu of the same type (MECD0007). But when I tested car after refitting socketed ecu, AFR was completelly diferent, much leaner in fact, even during cruise it go over 17:1 and off scale, while with nistune ecu it was nice 15:1, similar for idle. When I just use nistune ecu, everything is spot on again. I tested EPROM file, but it is really same file as is used in nistune ecu. Just note that car was tuned with disconnected stand. lambda probe (it was faulty) and situation is same if I use O2 feedback flags or not in fuel map.
Can be really something wrong with one of the ecu´s? for me it looks like one of them see incorrect AFM signal...

Matt · Post by **Matt** » Sun Nov 08, 2009 9:58 am

not sure. what you can do is take the same part# ROM image that works in the Nistune ECU

Then use the copy maps feature to copy the maps from the Nistune image to this ROM image. Then try burning that to the chip and see how that goes

If that doesnt work then try the chip in the Nistune ECU and see how that goes to check the other ECU

raddy · Post by **raddy** » Sun Nov 08, 2009 6:56 pm

both images are based on the same MECD0007 bin. basicaly, I used (already tuned) bin file from normal ecu, load it to nistune ecu, changed it, saved as bin file and burn to eprom and put back to the normal ecu. when I open it again in nistune, it doesnt ask for base file, as it is complete. did you mean that I should try to use original MECD0007 bin file and copy all maps to it?

Matt · Post by **Matt** » Sun Nov 08, 2009 7:28 pm

yes copy the maps into it and it should work

raddy · Post by **raddy** » Mon Nov 09, 2009 4:41 am

thanks for advice, I will test this way. can I ask you, if this will help, what would be an explanation?

Mydato · Post by **Mydato** » Wed Nov 18, 2009 10:00 pm

Matt could the Min Tpulse and Max Tpulse maps be mixed up? Try opening the bin in Romeditor and check Tpulse values.

raddy · Post by **raddy** » Wed Nov 18, 2009 10:16 pm

while working with nistune ecu, tp min and tp max working correctly, tp min affect idle, tp max affect high load, dont think that they are mixed up...

Matt · Post by **Matt** » Wed Nov 18, 2009 11:07 pm

the TTPmin/max are correct in the latest 0.9.13.x versions. I triple checked after all the dramas with working out why we previously had issues

TTPmin is 1/10 of actual display value, so I adjusted scaling to suit