High CO and MOT fail M100SE 1991

[chrism]

Thanks RonR. I found those smaller m/plugs and followed them down with my finger. Neither of them are empty connectors.But I did find a couple of S2 engine bay pics.

O2 sensora.jpg

O2 sensor 2a.jpg

I haven't got an empty m/plug where these pics show it might be. Does any other SE non-O2 sensor owner have one, please?

[TorqueHorse]

Hi TorqueHorse, on the B&C site why would the Turbo non cat ECM be £740 and the Turbo cat ECM be £144? seems a huge difference

Oh wow, I didn't know that. Supply and demand maybe since there are so many fewer cars running an O2 sensor? Good reason to convert over if your ECU breaks too I guess.

[TorqueHorse]

Chris, I think the O2 sensor wiring/plug is hiding behind your engine mount - see photo:

Image1.jpg

Hey Chris, sorry to be annoying, but I really think RonR has it pointed out in that photo (It has a bit of a lime green plastic band around it, showing in the photo, wedged between the motor mount and your engine bay frame) . Try snipping the white zip tie that is holding the two sets of wires together; that should give you more wiggle room when tracing the wires. Then you should be able to pull up on the connector we are talking about. It should have 3 wires going into a square connector back that has 4 holes - if you want to be sure. Or could you at least take another photo of that connector for more eyes/confirmation from the group?

[Simon_P]

Simon_P. If you mean me, thanks I screen-shotted my first 'Scan attempt,

I mean anyone - Can't tell much from a snapshot, its a bit like a stopped clock - Your IAC is at 12 and should be at 20 check for Vac leaks. I thought windows had a Zip programme ( right click on the file to see) if not 7 Zip is free.

But I did find a couple of S2 engine bay pics.

No you didn't those are both Fed.

[chrism]

TorqueHorse - certainly not annoying...Tomorrow I'll snip that thin small cable tie and pull up those m/plugs for the more proper inspection that you advised. I must say I did remember noticing the 4-hole connector that has 3 wires going into it even though I was looking for an unused, larger m/plug socket with 2 wires going in.

I'm really looking forward to being wrong ! It's not the first time I've embarrassed myself on this forum and this shows my naivety . I mean - fancy finding Fed pics and looking for a big Fed m/plug when my mates were tugging my sleeve saying 'no, really it's there...' and doubting their experience and input.

Thanks, too, Simon_P. I'll do a proper scan later and learn how to zip it for presentation on this forum. Your air leak observation makes a lot of sense and I reckon this could easily provide that 'combustiony' smell that isn't right...

I've said this in another post; this forum just keeps giving! Thanks All for putting up with my 'newbie-ness'. I'll report back asap but I'm feeling really good about the insistence and focus I've experienced

(ps assuming I find the O2 m/plug, anyone know where I can get hold of a 1499? ie is the cat-based A100E6533F ECM + O2 sensor - but w/out the cat - the way to effectively clean up the Elan SE emissions?

[chrism]

Yeeeesss I snipped the zip cable tie as advised by TorqueHorse and found two empty m/plugs thar RonR steered us towards that were clipped to the side of the bulkhead. I pulled up the one that Fredjohn identified by wire colours and:-

_DSF0309a.jpg

So, incredible 'hands-on' advice from a pretty impressive collaboration from forum-ers world wide Grateful thanks folks!!!

Now to shake Blasters sleeve again and find out whether his later map was a '1499' and how he got it into his ecu. I strongly suspect that it was a d-i-y integrated circuit plug-in that was an update into the original ecu - perhaps even from an S2 ecu or possibly an S2 whole-ecu substitution? Please tell more...

[RonR]

Chris, PM sent...

[Blaster]

Oops, I've just realised you were probably offering your map + CO meter to Twayblade, not me

Your welcome to use it after Twayblade. He is a bit more local and has collected it today.

[chrism]

RonR PM replied to thanks...
And Blaster, you're a gentleman, Sir Thanks a lot

[Chas54]

I changed to closed loop last year on my 91 elan after battling the CO for MOTs .
Initially i still struggled to get it to run well until a point where it had been running so long in my garage with the Gunsons CO meter and elanscan plugged up , that it ran low on petrol. I had previously filled up last time with E5 from Tesco . My local garage is Mobil and i got 10 litres of E5 there in a jerry can . The car improved immediately .
I should have known this is as i have a number of pre war Austin sevens and petrol left in the tank over winter always cause miss firing and starting issues.

Anyway after much wild goose chasing my elan is running better.

I do have available to loan the original ECU with the later 9930 chip installed (sept 2019) , a redundant but functioning CO pot, a spare MAP sensor, The original injectors (cleaned and flow tested) .

I also can claim some expertise on ringing cables though from sensors to the ECU plug . Thanks to Simon P , who suggested removing the plug locking shrouding- it makes it far easier.

I am South of Southampton in the New Forest.

[chrism]

Chas54, thanks for sharing your success.

I'm feeling a little deflated atm; ecu upgrade to 1499 is on its way but I've just discovered that the cables are missing by looking for an O2 sensor heater voltage between the black/yellow and earth at the engine bay m/plug - and it doesn't get better after days of soaking the turbo 'bung' with release oil that it just won't comply with my efforts at removal. I've got a 1" socket and an impact driver but it's all just 'one-job-after-another' kind of depressing...wheel arch liner + half moon removal too

I'm trying to get my head around the 'wiki' instructions and I'm unsure about signal wire and 3A rated supply wire, not to mention how to 'splice'.

Anyway your story's heartening and made me realise (and celebrate) why we do this

(Wanna share a bit more of your expertise on ringing cables? I, for one, sure could a light at the end of the tunnel...)

[dapinky]

I know that it isn't directly related to this thread (but it is!)......

..... it is possible to do a "PROM Dump" from the MEMCAL chip into a BIN file using Elanscan......

.... as such, it should be easy (for someone who knows what they are doing, and has access to the 'chip burner' hardware) to retrieve a 1499 map, and burn it onto your current chip.

In an ideal world, you would 'simply' get a new blank chip and burn the info onto it - but I know that when Alan was active he found that a percentage of so-called genuine chips were knock-offs and didn't work.....

.... that said, if you are unlikely to ever want to change it again, there are st5ill blank writable chips available, just not re-writable ones.

I have neither the experience or hardware to do these things, but if someone else has, then getting hold of the 1499 info is simple enough.

I *could* suggest that it would even be easy to copy a 1499 Everest PROM onto the new blank chip, and then fit the Moates adapter and re-create the whole "Mountain range.......

.... but there may be copywrite issues and disclaimers involved, so I won't be learning how to do it and selling them.

[chrism]

Yeah, and as a newbie all this discontinued chip stuff feels like turning up with a cup-final ticket, scarf, shirt, rattle and cans of lager only to find out that the match was played last week (Surely it can be continued in some way by those in the know who enjoyed the obvious benefits? )

What hope is there for PROM-id 9239-ers like me to enjoy relative security from the ravages of the MoT man and, incidentally, gain an extra 5mpg or so in the process - or get the performance boost celebrated and enjoyed by so many on the forum? (Except to be told "move along now, there's nothing more to see..." )

[Fredjohn]

Chris, couple of tips. I soaked the bung for days, then ran the engine to heat up the exhaust manifold, then put a 3ft long steel pipe over the socket wrench, then pulled! It cracked off quite loudly!!

Now you have found the O² sensor plug, bear in mind that although the other end is plugged into the ECU, there will be no signal as the ECU chip is not designed for that sensor, only the pot under the dash.

[RonR]

OK it's probably time to come out of the woodwork:

I've developed a moates-like board which has the capability to switch between 2 Prom images. Two prototypes are winging their way to Twayblade and ChrisM at the moment, with standard 9930 and 1499 images. Those Prom versions are the most commonly requested on here. Image selection is via a jumper on the board, so SE owners could go to 9930 for emissions, then go closed loop later on using the same board.

switcher-board.jpg

I've tested the board on a spare ECM but as my car's engine is on the garage floor ATM these two gentlemen have kindly agreed to be beta testers.

Once we're sure the board works correctly on these 2 cars I'll start a list for anyone who would like one.

[TorqueHorse]

very cool Ron!

[chrism]

Thanks Fredjohn I'll try that. I was thinking also of whacking an ice-pack on it when hot then using an impact gun and 1" socket. (a 24mm spanner is just too small - is it a 25mm bolt that's in there?)
Trouble is I'm 'afeard' of breaking or rounding something then getting really stuck...

RonR. Thanks. I'll be happy to report back asap on the 9930 side of things 'til I can overcome the other hurdles and go 1499, which is my ultimate target. I must say your timely intervention's been a breath of fresh air for people like me who've felt 'please sir, I want more...' or ''I'm having what she's having..."

[Fredjohn]

Thanks Fredjohn I'll try that. I was thinking also of whacking an ice-pack on it when hot then using an impact gun and 1" socket. (a 24mm spanner is just too small - is it a 25mm bolt that's in there?)

According to the Converting SE to closed loop instructions in wikilec it's a 27mm socket. A tight fit is important to not round the corners.

See here: http://wikilec.com/view/Converting_SE_t ... d_loop_ECU

[chrism]

Ah yes 27mm...thanks...

[Chas54]

Chris
Ringing the cables through isnt to difficult. Its only checking one end of a cable ends up at the point you expect it to .
You need a multimeter- quite handy if it has the bleep continuity sounder. If you have long enough cables on the meter, you can go through each in turn if you wish.
If you have the glove box out the car and the ECM un clamped , once the plugs are out you can remove the blue part of the plug by uncliping it. This gives easy access to the plug terminal and a piece of fuse wire held in the multimeter crocodile clip can be inserted next to each wire.
So you can go from the wing plug O2 sensor connection to the ECU and check its continuity


Checking the correct voltages is worth while .
I did the whole lot because i thought something was awry. You can have the plugs inserted into the ECU without the blue piece for testing.

I printed the ECU plug drawing charts and expected voltages diagrams from the ECU part of the workshop manual which is on this forum .(i think).
Then head in footwell and check readings.

When i removed my O2 sensor blank plug (lots of heating and cooling) I thought if i wrecked the plug i would need to think of a method of repair. I found the female thread was good though.

If you struggle to find the plug drawing I will fish some out for you .
Charlie