Hi CO of 4.5

[Blaster]

Since owning my 90 Elan SE it has always smelt rich. but runs and start well.

I have dug out my old Gunson CO tester and I am getting a reading of 4.5. I have tried adjusting the CO pot and only managed to lower it to 4.2 that was after 7 turns so I may have reached the end of the pot.

The Prom ID is 9329 so it is and old one. What is the best route to go closed loop as I have the wiring with the plug on the inner wing. Most of the threads I have read are old and the elanchips web site shows no stock of any options and no mention of my old 9329 chip.

MOT is due in November so I need to sort it soon.

[Fredjohn]

I assume you have a UK SE without any mountain chip. Prom id is usually 9929 or 9930. Or possibly 9239. Check the Prom Id decoder on the mountain chip site.

You will need to buy a 1499 chip with your choice of boost. Go to the shop and select V4 chip & adapter kit. Then 1499 etc. With the wiring in place you will also need the appropriate O² sensor. Check wikilec for the correct options.

I fitted the 1499 Everest chip on my SE and emissions went down from about 3 to 0.38. Result!

[Blaster]

Yes it is a UK spec SE with the original still sealed ECU with a prom ID of 9329 as read with elanscan.

I tried going to the shop bet all v4 kits are out of stock, it also does not offer the 9329 as an option.

[Fredjohn]

Existing prom id is not really relevant, you need to buy the 1499 chip, which changes the prom id to 1499 and allows the ecu to recognise the O² sensor and become closed loop.
As it is showing no stock, I suggest you email him. However, Mountain Chips is a hobby job, not his real life, so he may be a bit slow in answering.

CO adjustment instructions are in wikilec. Make sure engine is fully warmed up by cycling fans on and off a couple of times before measuring, and put it in service mode to adjust.

That's the best DIY help I can give without going to injector replacement or FPR issues (or new air filter?). Hope you succeed.

[Blaster]

I have been out and logged a run with elanscan and it is showing a maximum boost of 0.80bar with a sealed standard ecu with a 9329 chip.

The engine has been rebuilt before my ownership and has a large bore exhaust and I am not getting boost creep. There are no extra valves on the boost modulator and everything looks standard except all the pipework is Samco.

I have a dyno plot with it showing 181BHP not that I trust chassis dyno's for absolute power.

But still the CO is around 4% with a smell of petrol. Could it be the injectors have been changed, I have receipts for most of the upgrades but no injectors listed.

[theelanman]

The co pot has hundred of turns in it and its a very time consuming job........took me the best part of a day to twiddle mine.......
Have you got it in diagnostic mode when you're doing this....?

[dapinky]

The co pot has hundred of turns in it and its a very time consuming job........took me the best part of a day to twiddle mine.......
Have you got it in diagnostic mode when you're doing this....?

Whilst the screw will continue turning forever, as there are no end stops on it, the actual bit where adjustments are made is a very small window....... you need it attached to a monitor when you first move it, and count how many turns you have gone..... once the readings on the gas monitor no longer change, you have reached the end of the adjustment, so turn the other way until you reach the other end, then find the spot which works...

.... if you've moved it already, it may well be in a position where movement of the screw will make no difference as it's out of range - so it needs to be analysing the exhaust as you do anything.

[theelanman]

[Blaster]

Today I fitted the new MEM-CAL with 9930. I took the CO pot off and measured the resistance and it was at one end from me previous attempts to get the CO down. I then moved it to the centre of adjustment using a multi meter.

Put everything back together warmed up my CO meter and the engine and it came out at 2.1% I will leave it at that as it is an MOT pass and would rather be a bit rich than lean until I upgrade to 1499 with an O2 sensor.

[Blaster]

An update. I have now fitted an O2 sensor with a new ECU running 1499 map. Started first time with no error lights and according to ElanScan the air fuel was was 14.4. I have not taken it for a drive but there seems to be a bit of hesitation when a blip the throttle that I did not notice before.

Does the ECU learn and I need to take it for a drive as that will have to wait for it's MOT.

[TorqueHorse]

I have not taken it for a drive but there seems to be a bit of hesitation when a blip the throttle that I did not notice before. Does the ECU learn...?

It might be the IAC and you can read about it in the Engine Management.pdf (in the Manuals download section). Section EMK.2, pages 12-13. Idle Air Control (IAC) valve prevents against stalls, and the position needs to be 're-learned' by the ECM after a battery disconnect. Maybe it is in the 'wrong' position when you hit the throttle?
Suggested restart procedure after reconnecting the battery: Switch ignition on, then off and wait for 10 seconds. Then on again, before starting the car. Also, the ECM may try a full range reset (extending and retracting the IAC pintle to learn the position), once the car is up to 30mph for the first time after battery reconnection.

[Blaster]

Cheers, I thought that maybe the case as it is a brand new ECU made in 1991 and it is the first time it has been powered up.

[TorqueHorse]

Wow, blast from the past


That's great, I might need to get one too. Hope that is all it is

[Blaster]

Went for the MOT today.

On the way as soon as I gave it a bit a welly the engine light came on but stayed off if I drove carefully.

On the emissions tester for MOT it was reading 2.2% CO which is a pass but it should be lower with the O2 sensor. Never mind a pass is a pass.

Driving home I went to adjust the internal mirror and it fell off, luckily I had the MOT by then. Now to find some suitable glue.

Once home I had a thought, I had left the CO pot connected, disconnected it and now it works perfectly

[Fredjohn]

Tony
Interesting as when I fitted my O² sensor and corresponding chip, I didn't touch the pot. I assumed the ECU used the new sensor ilo the pot automatically.

Elanscan recognised the new chip and sensor and the really low MOT readings confirmed it was all working.

Can any boffins explain this?

[dapinky]

Tony
Interesting as when I fitted my O² sensor and corresponding chip, I didn't touch the pot. I assumed the ECU used the new sensor ilo the pot automatically.

Elanscan recognised the new chip and sensor and the really low MOT readings confirmed it was all working.

Can any boffins explain this?

Don't look at me.... I didn't touch mine either! (I just assumed it would be redundant and the ECU wouldn't request a value from it?????)

[Dave Eds]

Went for the MOT today.

Never mind a pass is a pass.

Being a nosey local, where did you take it for it's MOT Tony?.....

[Blaster]

I have a friend in Bishops Stortford and I needed to collect something from over that way.

[Rambo]

I have a friend in Bishops Stortford and I needed to collect something from over that way.

Slightly off topic, but have you heard of Invictus Motors in Bishops Stortford ? If so, any recommendations or advice, good or bad ?

[Blaster]

I have a friend in Bishops Stortford and I needed to collect something from over that way.

Slightly off topic, but have you heard of Invictus Motors in Bishops Stortford ? If so, any recommendations or advice, good or bad ?

I did not know they existed. Looking them up they are a bit out of the way and have not been in the barn long looking at Google earth. The barn does not look big enough to house 148 vehicles that they have in stock at present.

Back to the question I have no recommendation. What car are you looking at I can always test drive it for you.