Today when checking out the wiring and terminals for my vl i opened up the ecu to check for any corroded terminals and found no knock sensor board, could the ecu be a n/a one with a remapped chip or could the knock sensor board have been taken out. I also found the big capacitor floating around in the ecu, the car ran still but runs very rich. I replaced the capasitor with one out of a spare n/a auto ecu. Heres a pic of the inside of the ecu. Some original photos have not been recovered yet.

sounds like a stock na ecu with turbo injectors, that will make it run rich does the solder on the chip look different to the rest of the ecu?

i checked the solder for the chip and it looks like factory solder, it doesn't look like someone has soldered in the chip.

lol looks like it could be na mate thats why your running rich get a turbo one and enjoy an instant 10-20% more power at least. What does the sticker say on the front? If its a manual turbo ecu it should say 3tm

its defiantly not a VLT ecu, and its not an R31 ecu as they have a few capacitors in there for the variable fuel pump control. I looks likes a VL NA ecu but with an extra rom chip, that top left rom chip should not be there. my money is it has been chipped, go to the linmk below to see the differences between ecus http://wiki.r31skylineclub.com/index.php?title=ECU

the next step would be indentifying that rom chip and finding who supplied it.

Thanks for the info, the sticker says 3TM on the ecu but looks like the cover can be changed very easily. I compared the ecu to the N/A manual ecu i have and the turbo one has the extra chip but the chip looks like it has factory soldering. Looks like i will be looking for another ecu and maybe then i won't be using too much fuel. At least now i know why i didn't have a knock sensor code set because of no knock sensor fitted yet.

youve been ripped of then if it says 3tm!