RRC - Changing the ECM, from 13cu to 14cu or 14cux

[Ray Hyland]

I have a faulty ECM in my 1988 3.5l RRC.

I don't have a spare 13cu but I have a 14cu available.

Has anyone else done this swap? Anything special to note or look for? Or is it a simple matter of ensuring the output pins are correct?

Thanks!

Ray



Sent from my iPhone using Tapatalk

 

[mpinco]

A couple of good references:

13/14CU AND 14CUX SYSTEMS

I just scanned quickly but the pinouts look the same. The last 3 pages speak to tune levels for particular engines and years. While it doesn't include the 14CU, on the CUX, I would be surprised if they didn't have tune levels for earlier versions.

Service and Troubleshoot Rover 14CUX Electronic Fuel Injection

Scroll down to the "Control System" section to see where the tune version is specified for a particular ECM.

And

14CUX information

Appears the 14CUX would require a tune resistor that the 13CU and 14CU did not use/have.

 

[d110pickup]

Ray,
I may have a 13CU stashed away, I'll look this evening. if so you're welcome to it for the shipping.
Let me know.
Mike

 

[Roverchef]

The 14CUX has the tune resistor internally so don't waste your time looking for it. The only change that needs to be done other than just plugging it in is if you are planning on using your A/C. If so then you have to add a relay into the mix(as if Rovers don't have enough relays)due to the early 87-88 RR pin-outs needing some wiring mods to help the stepper motor(IAC) know when to "step-up" and not have the engine drop too low or stall. Some 89's even thou they had 13CU's and some had 14CU's in them they had a differnt harness that did not need "the fix". Let me know if you need exact wiring specs of where to jack into the harness.

 

[Ray Hyland]

Ray,
I may have a 13CU stashed away, I'll look this evening. if so you're welcome to it for the shipping.
Let me know.
Mike

Yes please Mike this would be awesome!

I am currently running on a "borrowed" 14cu.




Sent from my iPhone using Tapatalk

 

[Ray Hyland]

The 14CUX has the tune resistor internally so don't waste your time looking for it. The only change that needs to be done other than just plugging it in is if you are planning on using your A/C. If so then you have to add a relay into the mix(as if Rovers don't have enough relays)due to the early 87-88 RR pin-outs needing some wiring mods to help the stepper motor(IAC) know when to "step-up" and not have the engine drop too low or stall. Some 89's even thou they had 13CU's and some had 14CU's in them they had a differnt harness that did not need "the fix". Let me know if you need exact wiring specs of where to jack into the harness.

I plugged it in and the A/C seems to be working ok, other than needing a recharge. What should I look for?


Sent from my iPhone using Tapatalk

 

[jymmiejamz]

I plugged it in and the A/C seems to be working ok, other than needing a recharge. What should I look for?


Sent from my iPhone using Tapatalk

Normally with 14CUX the idle increases when the a/c compressor is energised in order to prevent a dip in rpm or stalling. If your a/c system is empty, the compressor will not engage and you won't have any symptoms.

 

[Ray Hyland]

The 14CU seems to have worked out ok so far.

We (Chris and Nat and I) just drove 9000km from the southern border of Canada/USA up to the Arctic Ocean in Tuktoyaktuk, dipped the wheels in the Arctic ocean, and then came back down. Got special permission to drive the new (unfinished) road from Inuvik to Tuk, so I believe we are the first to drive from the southern border to the northern border (ocean) in the summer time. We spent just over 3 weeks on the trip, and spent a bit of time in Haida Gwaii on the way back down.