ecu

[ed325i]

Hi, can anyone tell me what I will need to change from a 073 ecu to a 173 ecu. part from the loom and the ecu it self is there anything more I would need? I want to do this because Ant has told me they are better to chip.

[cabrio327i]

Hi. As well as the loom, you will need the crank position sensor, the later crank pulley with the pickup segments on it. the ignition pulse pick up on No-6 ht lead, and not sure but i think the starter on the later engine has different terminals for the loom so possibly a later starter? that should about do it i think. cheers Dave

[Brianmoooore]

Don't actually know what's different about the early starter, but I'm guessing that the early starter doesn't have the terminal with the 8mm nut for the load shedding relays. This doesn't really matter as, if you have the wire with no terminal to connect it to, it can be permanently earthed. The other connections are the black/yellow wire from the starter switch, and the large wire from the battery which goes to the outer large terminal on the solenoid, possibly along with another wire from the altenator.

[SeamanStaines]

But to be honest, it's a waste of time anyway. The early cars (metal bumper) had a higher compression ratio and were not catalyst prepped so really, there isn't much to be gained - about 5 bhp if you're lucky because they have the fuel and the timing characteristics the engine needs. The only thing you could gain is maybe a higher rev limit to shorten the engine's life further.
The plastic bumper cars were cat prepared - lower compression, milder ignition timing and a very lean fuel mixture to meet EEC emissions regulations. These can give up to 10 bhp with a remap but you remap these to give them back the 'go' of the older metal bumper cars...........