Scottish Elises

Assuming my ECU is a write off ('05 111S K-Series) what are my options for getting back on the road? Can I buy a new one, plug it in and drive off? Or will there be mapping etc required which I have no clue about?
Help...

Oh dear

It would help if we had a little more info i.e. why do you think your ECU is fried?

I have been through this - read my anguish and joy here

Good luck!

Reversed battery/battery charger normally results in fried ECU on 111S for reasons best known to Lotus. Buying a new ECU is the way ahead - I think Lotus do them on exchange, though I don't know if they actually repair them or simply recycle the chassis. Unfortunately I have not managed to get the MEMS3 running against the Lotus K VVC even though the MEMS3 K16 variant does work - cannot for the life of me understand what's different, but it doesn't work, so I don't have another option for you besides the Lotus K4.

You should check the impedance of your VVC solenoids _before_ you fit the new ECU in case you've fried the solenoids and then fry the new ECU trying to drive the fried solenoids.

No remapping or code matching required, though it will want to run the misfire learning program - if you order the ECU through MMC I'm sure they'll fit it for you and check the solenoids before doing so for only a few pennies. Considering ECU costs many 100 quid I would take this route for de-risking it if nothing else.

Cheers,
Robin

P.S. In the thread that Stewart referenced you'll also find everything you need to check everything else out before fitting new ECU and also name of repair company in case you decide to go down that route.


P.P.S. I wonder if Stewart's ECU was actually fine all along and it was the fuse that was causing the non-start - worth checking BEFORE you buy a new ECU I would say

Thanks for the advice. It's been a bit of a saga. Tried quite a few things on advice of a well respected lotus mechanic. Including changing IACV which made no difference. Then found 80A fuse had blown on the leg. Emgine was turning over and just revving up and down continually. Mechanic came to house, removed ECU, opened it up, identified possible blown chip and said he'd send it off to be tested and hopefully repaired. That was over 3 months ago. Every time I call him he says he'll get back to me. Now he doesn't answer phone. Feel like I've been duped but the guy has been great in the past so have no reason not to trust him.
I think I'm going to have to go with the MMC option although not sure how to make it move 20 miles with no ECU!!

I think you'll need the old ECU back as I suspect it'll be a p/x deal with Lotus to get a new one.

Cheers,
Robin

Munky wrote: Emgine was turning over and just revving up and down continually.

Dd the car start?? If so, fluctuating idle revs are a classic symptom of a low battery voltage. I have an S2 111S, and EU3 Rover VVC ECU available if you need to test something (rover ecu needs immobiliser bypass to work though) and lotus ecu isn't "readiy" available however......

Steve - are you running your car on the Rover (MEMS3 VVC) ECU? I've found that when you plug them into the Lotus that the car starts but runs incredibly rich and sometimes runs the fans all the time too - cannot work out why - something to do with A/C or missing sensor I suspect, but could never get to the bottom of it. I know there's a guy on SELOC that did it, but I think he took a Rover engine including the loom so perhaps he inherited whatever sensor or box is missing as part of that?

Cheers,
Robin

steve_weegie wrote:

Munky wrote: Emgine was turning over and just revving up and down continually.

Dd the car start?? If so, fluctuating idle revs are a classic symptom of a low battery voltage. I have an S2 111S, and EU3 Rover VVC ECU available if you need to test something (rover ecu needs immobiliser bypass to work though) and lotus ecu isn't "readiy" available however......

It did start but the battery was fully charged and functional according to my charger.
Electrics were doing a funny thing though. ECU and indicator lights flashing every time revs fluctuate down below 1000. Sounded like it was going to stall every time, then back up to about 3k. Just cycling. Throttle increased revs but didn't stop the fluctuating.
Think I'll take Robin's advice and see if MMC can source ECU and fit. It's been sitting for a while now so I've no doubt there will be other issues.

Would this work?
http://www.ebay.co.uk/itm/Rover-1-8-143 ... 2c6af10717

No, wrong ECU connector - that's a MEMS2J but the S2 uses the MEMS3 loom connector.

Cheers,
Robin

Hi Robin,

No, my Rover sourced VVC engine and MGTF loom came with an 160 EU3 ECU & although it started the car for a second until the imobiliser kicked in, it was obvious that it wasn't spitting out everything that the Stack dash needed on the canbus. Temperature for a start, but I suspect there would have been more....

I ended up shelling out for a bona fide S2 111s ECU & have done precious little else with the Rover unit. Shame really as the rover ecu looked like it was 99% there & pretty straightforward to map also...

You will be missing speedo output and coolant temperature output. I have a wee board that can be glued into the ECU to correct those two issues.

Everything else works, except for the random fan issue and the overfuelling I mentioned.

So your engine is a Rover engine, Rover loom and Rover sensors/injectors/fuel rail but runs fine on the standard Lotus K4?

Cheers,
Robin

Think Steve's is an MG ZR engine, with the loom from my TF on it.

I have another TF loom, Rover ECU and the post 5AS box of tricks that goes along with it here, though not much use if there's no way of getting the temp & speed on the stack on an S2. Have heard of people on seloc using the Rover set-up, but that was on S1s IIRC.

I have a wee board that I glue into the MEMS3 (Rover ECU) to make it spit out the temperature and speedo signals to make the dash work. The problem I have is that I cannot get the VVC variant of the MEMS3 to run the EU3 VVC engine properly in the Lotus. Obviously the mechanics of the engine are identical and most of the sensors, etc., must be the same too. The problem is that it runs really rich and I cannot work out why that would be, unless it's something daft like different injector flow.

Cheers,
Robin