File Review Request

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Re: File Review Request

Postby chrism » Sun 18.01.2026, 23:20

Yep I reckon the both smoke and the 1499 upgrade are incidental cos we've established your low battery volts. Agreed It could be either alternator or battery. (I suspect the alternator tho...)

Switching the lights on could stress any weakness in either so that's a good spot by Ken :)

NoahR it's a bit of a faff but why don't you eliminate the battery suspicion by using jump leads to jump start your car from a pals healthy battery and running another EScan as it ticks over connected to this battery (or just by looking at a live reading - I haven't needed to do this, but I gather others have.)

I've never had to do this before either, but if EScan shows a battery voltage of 14.4 then you've found your solution...KenS, reckon this could work?
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Re: File Review Request

Postby KenS » Sun 18.01.2026, 23:55

Agree Chris, jumping the battery may help totally rule out the battery, probably disconnect the battery from the donor car as a precaution.
The laptop issue and putting the lights on makes full sense of that anomaly in the plots so thats put to bed. The Voltage dip due to lights being on also supports bad alternator since it should be able to cope with the extra load.
Did the smoke occur as soon as the engine started, when the exhaust was still cool, or only after it had warmed up? Hopefully the latter. Also, if it has only started smoking now and not on previous runs with low 12V, it implies the smoke is not related to the alternator. So I think the smoke has to be the steering fluid on the exhaust or on the alternator belt.
Hopefully all the evidence points to only having an alternator issue, if that is the case, best to check the alternator has good connections and earths, if you have the test kit, there is a procedure in the Electrical manuals Page 37 that describes some tests to prove the alternator but it will be quite a job to make the connections for the tests.
Wouldn't harm to measure the voltage at the battery terminals with the engine running, just to make sure the 11V-12V seen by ElanScan is a true value and that volts are not being dropped across a connection somewhere. If the volts there are low I think you will be at risk of unreliability if no action is taken. Good luck.
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Re: File Review Request

Postby chrism » Mon 19.01.2026, 01:21

Yes, agree about jumping off a disconnected, but known good, battery and doing an EScan to eliminate it.

Would be good to confirm that battery volts = EScan volts.

Presumably the dash voltmeter reads 12V on initial switch on and doesn't rise after engine starts up (as it should...)? Battery known to be fully-charged?

Running out of ideas but gut-feeling still suspecting regulator/rectifier pack
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Re: File Review Request

Postby chrism » Mon 19.01.2026, 01:49

Image

Blue + black are your before and after EScan plots and the pink is mine. Your voltages start low and go high with a small time-lag. I don't know the significance of this but could it be a poor earth connection somewhere causing a 'struggle' to get charge moving?

Clutching at straws here...
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Re: File Review Request

Postby Tuga2112 » Mon 19.01.2026, 10:04

chrism wrote:Presumably the dash voltmeter reads 12V on initial switch on and doesn't rise after engine starts up (as it should...)? Battery known to be fully-charged?


TLDR as far as the post full context. but this specific quote is inacurate.

firstly the dial is not very accurate. but 12.4 - 12.7 is the ideal resting voltage with the engine off.

with the engine on. you are hoping for 14.xx as the alternator will be charigng the battery. and the energy being consumed should be all generated from the alternator.
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Re: File Review Request

Postby RonR » Mon 19.01.2026, 13:58

KenS wrote:Also, the Air/Fuel ratio is very well controlled at about 14.7 which is the optimum value and achieved by the the ECU in response to the O2 sensor value, again a good indication that closed loop is working well.


From what I've seen the ECU's Air/Fuel ratio field has 2 functions:
1. In Open-loop it's the actual AFR.
2. When the ECU enters closed loop, 14.7 AFR is set as the target, the actual AFR varies a little around that figure, where the 'Oxygen Sensor Correction' field is used in the fuelling calculations.

Yours looks to be OK Noah.
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Re: File Review Request

Postby chrism » Wed 21.01.2026, 11:20

re:- "Presumably the dash voltmeter reads 12V on initial switch on and doesn't rise after engine starts up (as it should...)? (TLDR as far as the post full context. but this specific quote is inacurate.)"

Tuga, sorry but I think that you've misinterpreted my statement. I'm implying that - irrespective of the numbers behind the decimal point - the dash voltmeter should read ~12V at initial switch on and read ~14V with the engine ticking over.

Probably too many words in addition but 'as it should' was meant to imply a rise to ~14V from ~12V after the engine started...

I hope this 'sorts' our issue and that NoahR can use this to help solve his problem :D: (It seems from his Blaster/smoke post that he's never seen 14.xxV with his battery/alternator combo and I believe we all agree that he should have?)
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Re: File Review Request

Postby NoahR » Thu 22.01.2026, 22:40

Hi all,

I hadn't actually noticed this thread had continued onto a second page, hence my lack of reply!

NoahR it's a bit of a faff but why don't you eliminate the battery suspicion by using jump leads to jump start your car from a pals healthy battery and running another EScan as it ticks over connected to this battery (or just by looking at a live reading - I haven't needed to do this, but I gather others have.)


That's a good suggestion. My other car is a 2004 Honda Jazz, so I will try that! Apart from, as KenS said, disconnecting the battery from the Honda, I assume it would just be a case of a classic jump start? - Would you disconnect the battery from the Lotus as well and connect the jump leads to the cables or not? Sorry, silly question, just not sure!

The laptop issue and putting the lights on makes full sense of that anomaly in the plots so thats put to bed. The Voltage dip due to lights being on also supports bad alternator since it should be able to cope with the extra load.


Yep, the voltage consistently dips quite a lot when I turn the lights on.

Presumably the dash voltmeter reads 12V on initial switch on and doesn't rise after engine starts up (as it should...)?


Bang on.

Battery known to be fully-charged?


Can't confirm - I'll do some testing with the multimeter, but it could be low. The car has a battery isolator installed, specifically because there was a 'slow drain' on the battery. I wonder, however, if given the alternator and voltage situation, it was instead just charging very slowly.

With regards to the further questions/points, the plan is to work on the car tomorrow evening and Saturday, so I will let you all know. I'll test the voltages using another battery, check the alternator connections, and check the battery voltage with a multimeter to confirm its both okay and that it matches ElanScan.

Thank you for the help and thoughts/input, everyone! - I'll let you know what I come back with :)
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Re: File Review Request

Postby chrism » Fri 23.01.2026, 00:12

A jump start would work but I think I would disconnect the m100 battery altogether. (It's a pig to release the fixing plate bolt to take the battery out, if I remember correctly - and even more difficult to get the bolt back in place...)

But please make sure that all the bare connections are well insulated. They'll be fairly close to the fuel filter that could be leaking petrol vapour into the boot space.

Yes they all leak charge. (I plug mine into a smart charger when I'm not using it.)

Yep, feedback always welcome :). I'd be especially pleased for you if the dash voltmeter gets up to ~14V on tickover.
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Re: File Review Request

Postby NoahR » Fri 23.01.2026, 13:30

Lovely, thank you for the info ChrisM.

I remember having a look at the battery the other week. I got access to it rather easily, but I couldn't figure out how to loosen the nut connecting the negative battery terminal to the battery. None of my sockets or spanners had enough clearance to actually get on the nut itself. I'll have a longer play with it this time though.
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Re: File Review Request

Postby NoahR » Fri 23.01.2026, 18:19

Hi all,

Super quick update from just now;

Made sure the green cable was plugged in - it was. Hard to access haha!

The battery volts with the car off were 12.28, with the car on they steadily rose from about 12.56 through 12.71 and kept going up slowly, with the car on and headlights on, they were 11.84.

Any advice on removing the negative battery terminal nut? I can't get a socket in that location (I could buy and try a super low-profile socket, but not convinced it would work), and I can't get either end of a spanner on there as the nut is just too shallow to get a bite on. Tried vice grips as well. - Picture:

Image

Finally, good news RE the smoke, it didn't smoke in the 5 mins or so I had it running, so perhaps further confirmation that that was just the power steering fluid burning off, and that instead this has just maybe uncovered a general issue, one occurring before the closed loop conversion??

Will crack on with the other bits tomorrow.
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Re: File Review Request

Postby chrism » Fri 23.01.2026, 18:38

So this is your original m100 battery that seems to mirror your dash voltmeter readings, then.

Sluggish, but something seems to be getting through from the regulator then? I think I'd try that different battery idea, now.

Can't remember seeing a green cable on mine? And that nut couldn't be more awkwardly aligned. Spraying with pen oil, leaving it to soak for 1/2hr and tapping it with a sharp screwdriver or punch...?
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Re: File Review Request

Postby NoahR » Fri 23.01.2026, 18:44

chrism wrote:So this is your original m100 battery that seems to mirror your dash voltmeter readings, then.


Yep.

Sluggish, but something seems to be getting through from the regulator then? I think I'd try that different battery idea, now.


Yep, for sure. Job for tomorrow.

Can't remember seeing a green cable on mine?


The actual cable is encased in a black covering, but the connector into the alternator is green.

And that nut couldn't be more awkwardly aligned. Spraying with pen oil, leaving it to soak for 1/2hr and tapping it with a sharp screwdriver or punch...?


Ah thats a good shout! I've done that before on other bolts, but that didn't come to mind here
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Re: File Review Request

Postby MPx » Fri 23.01.2026, 22:10

Obvs if you do ever get those off, reverse the bolts and put the nuts on the outside!
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Re: File Review Request

Postby NoahR » Fri 23.01.2026, 23:48

MPx wrote:Obvs if you do ever get those off, reverse the bolts and put the nuts on the outside!


Certainly! - I question how whoever touched it last got it in there like that.

Just in case it's relevant, my Honda battery tested 12.37 volts with the engine off. A bit low? So, not sure if that will have an impact on the Lotus.
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Re: File Review Request

Postby MPx » Sat 24.01.2026, 00:35

Could you get one of these on it? 10mm socket with UJ
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Re: File Review Request

Postby NoahR » Sat 24.01.2026, 17:00

Successful update!

Started by changing the fuel filter today, which in the process required me to remove the battery (pen oil and a screwdriver worked to get the nut off - thanks for the other suggestions though).

That all went well, and when I turned the car on, lo and behold, the voltmeter was reading 14v! Could this have just been caused by a loose connection to the battery, which was fixed when I removed and reinstalled it? While obvious in hindsight, because of the issues actually getting the terminals off, it's not something I tried.

I then iddled it for a little while before taking it for a spin down the road for an hour (booked in at an MOT centre, with their permission), which in turn has, as expected, fixed my white smoke issue!

I've uploaded my Elanlscan files, realrun1 contains my idle from cold with a bit of revving, and a drive to a fuel station. realrun2 contains my drive after that. - Note, my laptop went to sleep about 10 min away from home, and I was only able to wake it up again just as I was parking the car. I can't quite work out yet if it included the data while it's asleep or not, but that would explain any weird gaps. Another thing to note, the voltage drop while idle occurred when I turned everything in the car on to put a strain on the battery. - https://drive.google.com/drive/folders/ ... sp=sharing

Very successful day indeed. - Real MOT is booked for Tuesday. I've just noticed the driver's side front anti-roll bar bushing is split so its disonnected there - this video https://www.youtube.com/watch?v=LyNKWtTfXqA seems to have a fix for me though.

Thanks for the help so far all!
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Re: File Review Request

Postby chrism » Sat 24.01.2026, 17:36

That's really good news :D :D. I think I'd clean up and 'vaseline' the battery terminals too, while you're on a roll...

Hmm...could the non-charging merely be down to corrosion of the battery terminals causing high resistance etc etc?
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Re: File Review Request

Postby RonR » Sat 24.01.2026, 17:43

Just had a quick look at your Elanscan files and all seems fine.

Looks like you gave it some beans on the second run! :burnout:
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Re: File Review Request

Postby chrism » Sat 24.01.2026, 17:51

EScan reads that battery volts in both realrun1 and realrun2 are ~14V now:-

Image

O2 sensor and air:fuel ratio are spot on. I'd say that was a win/win NoahR...congrats...loadsa luck with the MoT.
Last edited by chrism on Sat 24.01.2026, 23:08, edited 2 times in total.
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