CAS replacement - advice please

[Fakejudge]

Hi all.
Any advice gratefully received.
Some time ago my Elan suddenly decided not to rev or generate any power - it was similar to a modern car running on 'get you home' mode.
Had the injectors checked and found one not working. Changed them and the coil packs at same time.

Then the engine pulled very well after about 3500 revs but very badly below - very lumpy running, misfiring and no power below 3500 revs.
Was advised possibly hall sensor so had that changed at a garage. But no change in running.

The garage did say it was showing fault code 41 - and possibly throttle sensor issue. Which is usually associated with hall sensor.
They are now advising replacing the entire CAS with a new one. But its a pretty pricey part - so before I did that I thought I'd ask if anyone had any thoughts?

Or I could wait until a Lotus specialist near me (PNM Lotus) has an opening - but that might take some months....

Cheers.

[chrism]

Fakejudge, I'm sure there's a queue of LEC-ers behind me bristling with the same advice that it's not always a bad idea to replace parts on a 30+-year-old Lotus but (bearing in mind current Lotus prices ) an ElanScan might necessarily be a good 'first call' if your m100 is having running difficulties.

If you include your region in your avatar then, perhaps, one of our esteemed ElanScanners might be able to come forward and use their diagnostics to help focus down on (and save your garage) the option of throwing ever more expensive solutions your way...

Hope this helps.

[Fakejudge]

Thank you. Updated avatar with location.

I think you might be right that I should put my hand in my pocket and just buy the CAS!

I don't suppose you know where is the current best place to buy an Elanscan cable? I do have the bits to make one but finding it hard to find the time.

Regards, D

[chrism]

Buy CAS? Phew I think I'd prefer to EScan it first !

I think Tuga's been making cables, a pal bought one from ebay recently and Geoff's still around who used to make them...

I'd recommend a local pal, with a known working cable and l/top software, who knows their way around ElanScan to show you the ropes in the first instance then you can take your time to make the cable up and download the latest software - which dapinky made a 'sticky' on the forum home page - at your leisure w/out encouraging mission creep

Let's hope someone close to you can respond

[Fredjohn]

Before splashing out more hard earned cash, have you checked the base timing?

Full instruction are in the workshop manual, available on here for free.

Would agree to using elanscan too before CAS replacement.

[Tuga2112]

i got the hardware to make a few cables. but my 3d printer is offline. so i cant make the boxes to protect the electronics.

currently with my turbo rebuild work progressing at snail pace. i wont be fixing the printer for a while. im hoping to have a couple done for CC later next month. even tho last year there was no takers.

[Fakejudge]

Thanks. I would defo be interested in a cable.

[RonR]

If the CAS has a mechanical fault then replacement is the only way, BUT:
The Hall sensor inside the CAS can be adjusted (Sensor gap to reluctor wheel), or it can be replaced for much less than a full CAS.
An Elanscan should show you if the CAS pulses are going missing, and if there are too many faults the ECU will turn on the CEL.

Edit:
Also - the coil base plate has some active electronics. It's insulated from the longeron and there's an earth connection from the loom on one of the mounting bolts. Right under the coolant reservoir!
Worth a check in case there's some corrosion there.

[Fakejudge]

Just to say thank you for all the advice. I'm running it up to a Lotus specialist next week - so crossed fingers...

[Fakejudge]

So Lotus guys traced this to an ECU issue - ECU temp circuit reading outside temp at -40 degrees (!) and massively over-fuelling. That led to gungeing up of TPS and 'cold start' sensor in the intake (now rectified).
However having trouble finding an ECU repair business that can fix - ECU Testing in Heanor can't do anything as they have no system that can communicate with it.
Anyone know a firm that can help?
Many thanks.

[Fredjohn]

SW Lotus have new ECU/ECM on their website.
Contact Mike Hope.

[chrism]

Fakejudge, w/out 'dissing'* your Lotus guys I'm wondering what their 'ECU issue' is? Those symptoms sound very much like dapinky's coolant temperature sensor issue to me...

If your guys used some kind of scanner and it shows that you're getting smoke/over-fuelling at some sort of temp of -40C (dapinky's was -38C) then it could make them think 'ECU fault' - but it's the CTS that feeds this info into the ECU and I've known a couple of CTS failures fairly recently within my own circle; I haven't experienced ECU failure (touch wood ) tho'.

Imo before parting with a kidney and buying an ECU (phew £350+?) I'd at least try a pal's (they're easy to remove) but, I reckon, first search out dapinky's CTS post?

ps any luck with your ElanScan quest?

*(...not an expert; just an opinion...)

[dapinky]

I was just about to jump in with what Chris said......

..... I'd consider the CTS first.

It can be tested without removing it from the car, as the WikiLEC gives a range of resistances that should be output depending on the actual temperature.....

.... Mine failed at 'high resistance' which sends a -38c reading to the ECU, whatever temp the actual coolant is at.

FYI, a new Elan CTS costs an awful lot more than a new Esprit one - even though they are the same part....... and there are many alternatives out there anyway, Standard TX3 is a suitable aftermarket part.

[wayne]

Had a similar issue many years ago and it sounds similar to Dapinkys description. Garage door down and rev the car and loads of soot on the door, it was the CTS. Replaced it and its been fine ever since. I bought an aftermarket part very cheaply from somewhere but dont remember where, sorry that was over 15 years ago and I'm getting old and forgetful.

Will try to dig through my emails to see where I bought it from.

[Fakejudge]

Many thanks for this. Given the cost of the sensor, I've ordered one to give it a try. Can't hurt to replace it anyway.
NB, Haven't been able to source the interface cable yet.

[chrism]

Yes, my thoughts are similar; it's probably a good first thought to replace 36-year old sensors if they're cheap and suspected of being 'duff'...

re difficulty getting hold of a cable, there is (or was) a bluetooth version of the EScan adapter that KenS developed. A bit more in keeping with the modern age and it can also pair with an android phone app that can read engine parameters. It won't graph them but I gather that the data can be imported into Excel if you want graphs...

My 2013 (win7 originally) l/top won't update to win11 but it runs ElanScan absolutely perfectly with Ken's adapter bluetooth-ly(?) paired with win10. (I suppose it bypasses the com port 'upgrades' in the newer win versions that don't want to play nicely with EScan?) It was a used 'cheapie' that I bought in the early win10 era to run EScan, but I soon noticed that there were problems as it updated itself to the later versions of win10 and subsequently into win11

[Tuga2112]

lty getting hold of a cable, there is (or was) a bluetooth version of the EScan adapter that KenS developed. A bit more in keeping with the modern age and it can also pair with an android phone app that can read engine parameters. It won't graph them but I gather that the data can be imported into Excel if you want graphs...

i have the hardware int he box to make another 3... just need the printer working. if you keep talking about bluetooth alternatives ill never shift this stock

[chrism]

Oo'er...better pipe down then else I might get an m100 front spring through my kitchen window...

[wayne]

lty getting hold of a cable, there is (or was) a bluetooth version of the EScan adapter that KenS developed. A bit more in keeping with the modern age and it can also pair with an android phone app that can read engine parameters. It won't graph them but I gather that the data can be imported into Excel if you want graphs...

i have the hardware int he box to make another 3... just need the printer working. if you keep talking about bluetooth alternatives ill never shift this stock

Hi Tuga, I dropped you a msg a few days ago but maybe it didn't go through. I'd be interested in 1 of your cables if you ever get your 3D printer working or find another suitable box. Please can you save 1 for me?

[wayne]

lty getting hold of a cable, there is (or was) a bluetooth version of the EScan adapter that KenS developed. A bit more in keeping with the modern age and it can also pair with an android phone app that can read engine parameters. It won't graph them but I gather that the data can be imported into Excel if you want graphs...

i have the hardware int he box to make another 3... just need the printer working. if you keep talking about bluetooth alternatives ill never shift this stock

Hi Tuga, I dropped you a msg a few days ago but maybe it didn't go through. I'd be interested in 1 of your cables if you ever get your 3D printer working or find another suitable box. Please can you save 1 for me?