S14 Base Image

[S14Kouki]

I have a 1997 Nissan 240sx SE that was auto to manual swapped using a manual 1996 ECU. The ECU harness was repinned to use the 96 ECU. The base image on the factory ECU was 72F02 and my type 4 dual rom board has 72F01 on it. Everything works fine except it seems while the ECU is running in closed loop during warm up I get spikes in the injector duty cycle. It causes extremely rich stumbling during idle. It will run fine for as long as 10-15 seconds before it stumbles and when it does my AFR gauge reads mid 10's. The Ka24DE is completely stock (injectors, MAF, no turbo) so the base image shouldn't have affected the way it runs. If I drive it during this time and Idle in first gear the car will die unless I push the gas. Would the base image cause this rich stumbling at idle during closed loop? After the car warms up it runs fine.

[S14Kouki]

I have attached a log file of the engine stumbling. It looks as though the injector time jumps and the timing swings. Only happens when cold.

Edit: I have attached another log where it happens repeatedly. Injector time gets as high as 7ms, timing fluctuates from 27BTDC to 12BTDC at idle.

[Matt]

Very strange. Try removing the board and putting the R025/R022 jumper back to factory and relog when cold to see if it happens. First thought is board image has been corrupted?

[S14Kouki]

Since originally posting, I have tried a friends ECU which had the same part number and base image as my factory ECU and I tried an Automatic ECU with a 72F11 base image (All ECU's were '96). Both ECU's worked fine and the stumbling was gone when cold. This morning I removed the nistune board from my ECU and moved the jumper back to stock and drove to work, no stumbling at all. I have attached the log from my drive to work. I have an Auto ECU I can use as a backup if you need me to ship this ECU.

Thanks,
Chris

[Matt]

Since is a different part number, might need this one shipped