Lotus Elan Central

by **MJR** » Thu 16.03.2006, 14:08

Do you need the car in diagnostic mode to adjust the c o? As you do with the base timing.

Many thanks

by **pjohn151** » Thu 16.03.2006, 14:09

Yes, and make sure that the engine speed is about 950rpm whilst in diagnostic mode before you adjust the CO

Phil

by **Enright** » Thu 16.03.2006, 14:10

I didn't think that you did - I've always messed around using a Gunson's Gastester with mine while idling normally, and it seems to have worked fine. Having said that, I'll be interested to see what the results of my MOT are tomorrow!

Does it say so in the manual? If so, can you point me in the right direction? I'd rather be doing it properly!

by **pjohn151** » Thu 16.03.2006, 14:17

In the Engine Management Manual EMK.1-F it states that

if the diagnostic terminal 'B' is grounded with the engine running, the system will enter CO adjustment mode and the 'Check Engine' tell tale will light. See Section EMK.3 - E for the CO adjustment procedure.

Checking the EMK.3 - E, it does not mention having the engine in diagnostic mode, implying you just run the engine up to temperature so the cooling fans cycle on and off, make sure all electrical stuff is switched off and adjust away...

Phil

by **Enright** » Thu 16.03.2006, 14:26

Oh that's a relief!

I wondered if you might have to park IAC valves and things to get it spot-on, or risk getting up Mr.MOT Tester's nose again.

Nice to know that at least I haven't buggered anything up (for once). :lol:

by **pjohn151** » Thu 16.03.2006, 14:29

Sorry, edited my last post...
:oops:

Phil

by **MJR** » Thu 16.03.2006, 14:31

Just found in the manual: EMK.1-F
Its seems to state you should be in diagnostic mode unless i am reading it wrong. Could anyone clarify?

Martin

Sorry too quick. just noticed its already been mentioned (EMK.1-F)

by **pjohn151** » Thu 16.03.2006, 14:42

I adjusted mine in diagnostic mode, allowing me to correct the base idle speed as the mixture was adjusted back to 950rpm. After taking it out of diagnostic mode (taking the paperclip out), the CO reading was the same as when in diagnostic mode

Hope this helps

Phil

by **Guest** » Thu 16.03.2006, 15:44

Phil
Did you find the c o pot needed very fine adjustment? A very small movement altered the reading dramatically, and then difficulty getting it spot on? I find i move it one way by a very small amount and then the needle on gunson moves very high. Just wondering in case i have a tempermental co pot.

Martin

by **a5gcd** » Thu 16.03.2006, 18:19

Martin
If you are coming to Donington, Bring your Gunson with you and we can do a group test. :lol:

Geoff

by **Guest** » Thu 16.03.2006, 19:12

Hello Geoff

Sorry but cannot make that one.

Martin

by **Enright** » Thu 16.03.2006, 21:24

a5gcd wrote:Martin
If you are coming to Donington, Bring your Gunson with you and we can do a group test.

Geoff

Not sure how serious you were being, but I could quite feasibly do that. Seeing how I'll have the emissions report from my MOT the previous day I'll know how far the calibration is out, and then we can just go from there.

by **pjohn151** » Fri 17.03.2006, 08:30

Phil
Did you find the c o pot needed very fine adjustment? A very small movement altered the reading dramatically, and then difficulty getting it spot on? I find i move it one way by a very small amount and then the needle on gunson moves very high. Just wondering in case i have a tempermental co pot.

Martin

Martin,
Yes I did find the CO pot was quite sensitive - I think there was only about a quarter of a turn between an MOT fail and ~1% CO reading on the emissions.

Phil

by **Darren** » Fri 17.03.2006, 12:20

pjohn151 wrote: Martin,
Yes I did find the CO pot was quite sensitive - I think there was only about a quarter of a turn between an MOT fail and ~1% CO reading on the emissions.

Phil

I seem to remember that there was a memcal firmware upgrade to allow a further adjustment of the CO2 pot.

Can't remember the specifics but I know it had something to do with a change in the MOT laws and the fact that some Elans couldn't pass the revised emission controls.

Darren.

by **a5gcd** » Fri 17.03.2006, 13:00

Enright13 wrote:
a5gcd wrote:Martin
If you are coming to Donington, Bring your Gunson with you and we can do a group test.

Geoff

Not sure how serious you were being, but I could quite feasibly do that. Seeing how I'll have the emissions report from my MOT the previous day I'll know how far the calibration is out, and then we can just go from there.

Totally serious. I have recently had to reset my CO pot to overcome rough idle after fitting an Everest chip. I did it while monitoring the injector duty cycle with ElanScan, so I would like to confirm the setting with an exhaust gas analizer as soon as possible. My friendly MOT man is not so friendly when I ask him to do something for nothing!!

Geoff

by **Enright** » Fri 17.03.2006, 13:47

OK, it's in the boot ready.

by **pjohn151** » Fri 17.03.2006, 13:49

Darren,

That will be 1995/24. I have supplied Sy a copy for the Service Manual to be updated. It also refers to a service bulletin 1991/04 regarding the operating ranges of the CO potentiometer.

Phil

by **a5gcd** » Fri 17.03.2006, 15:51

Enright13 wrote:OK, it's in the boot ready.

Cheers, see you there :-D

Geoff

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