14CUX ECUs what's the difference?

[Rustyrangie]

Hi, a quick query for the Efi wizards.

My RRC (89 3.9 V8 efi, non-cat) has an ECU, LR part No. 8702 which my parts manual CD calls a 14CUX

I've just bought a spare ECU (dirt cheap) off eBay which is LR part no PRC 9611, also marked 14CUX!

My question is, are these interchangeable? if not why not? and what's the difference between them software, mapping or what?

I run mainly on LPG so the Petrol ECU is hardly used except for starting.

Any help will be gratefully received.

Happy Easter to all.

Bob 3.9V8...(slowly coming back together after a "quick check over for the MoT" 5 months ago!)

[DEANO3528]

Have a read on Carelect

[Rustyrangie]

Have a read on Carelect

Thanks Deano,

interesting site, I've added it to my favourites. Looks as if the coolant temperature sensor is the root of all evil, efi wise.

Still doesn't really answer the question, although it refers to the various part nos. for the 14CUX so the inference is that they are interchangeable.

Cheers,

Bob

[Ally V8]

The answer is that they all have the same functionality,but there will be different fuel maps for 3.5's in Disco 1 and 3.9 and 4.2.in RR classic.Then there there all the others such as Morgan Plus Eight and TVR etc.As far as I'm aware they will all run open or closed loop depending on the tune resistor that is plugged into the loom about 9" away from the Ecu plug.If you only use it to start and then go straight to LPG any of them should do this but you may have problems if running say a 3.5 part number in a 4.2.You would need to trawl through EPC or microcat to get all the Part numbers in the order they superceeded or to find if indeed the one you have bought is for the right capacity motor.