ECU question

Hi there,
I hope someone can help - i have a UK 1995 audi A4 -90HP 1Z engine with an ECU no. of 028 906 021F. I have the opportunity to buy another ECU which i think i may get chipped - this other ECU is also from a 1995 audi A4 but the part no. is 028 906 021FL. Can anyone tell me why there is an 'L' at the end of the part no. and if this will cause me any compatability issues?
I know my ECU should be socketed and that it should be relatively simple to just put in another chip but at the price of the spare ECU its worth having just for peace of mind should i cock something up!!!

Cheers
Andy

Most of us here at Fred's hail from the US or Canada. We had no TDI until the 96 model year. The ECU for the 1Z engine for 96 has a BK suffix or a replacement with a GQ suffix. The 97 1Z came with an FA. The 98+ 1Z had a JA if the reports I hear are correct.
You may wish to open both cases and do a side-by-side comparison to note differences. It may have been simply a different component supplier or assembly company. It may be an entirely different structure and format, but with exactly the same outputs for given inputs, such as the BK / GQ over here. Your aftermarket chip supplier may also have the answer.

It is interesting to note that for the 'FL' the parts catalogue says "also use conversion kit for two part flywheel". The 'F' is/was superceded by 'FE'. The suffixes can indicate different software programming.

Can anyone else shed any light on this two part flywheel issue? Although how exactly the ECU is connected to the flywheel i have no idea - perhaps if it were quattro or automatic transmission then there may be some electronics related to the transmissin but my vehicle is just the standard 5 speed transmission.

Any thoughts anyone?

MOGOLF - Is that parts catalogue available on line somewhere?

Cheers
Andy

No it isn't and I haven't located any other information.