Closed Loop conversion advice.

[JohnB]

Has anyone done the closed loop conversion fairly recently and if so, offer any advice as to any pitfalls I might encounter. I know I may have some problems getting the bung out for the oxygen sensor but any other advice would be a big help.
I intend to fit an upgrade chip as soon as I have all the necessary wiring in place.
John.

[chrisP]

The wiring in the drivers side wing and through the dash to to ECU if it is not in existance, is your main headache, but there is a write up round here somewhere. I saw a few more MPG after the conversion and cleaner exhaust gases once the engine warms up and goes into closed loop.
Chris

[Fredjohn]

but there is a write up round here somewhere

It's in WIKILEC under http://wikilec.9600.org/index.php/Conve ... d_loop_ECU

I've not done it, just read it . Good luck

[JohnB]

Thanks Chris.
The wiring from the ECU to the multiplug under the O/S wing will need to be installed on my car, although the wiring from there to the oxygen sensor male plug in the engine compartment is already in place. Don't know why Lotus decided to leave this unconnected to the main loom. Very strange.
Something for me to do over the winter anyway.
Thanks also Fredjohn. I read the write up on Wikilec but just wondered what problems people might have encountered.
John.

[Jeemy]

I have all the parts here and will be doing it soon, with as many photos as I can take! I am not sure precisely when, as I am busy removing things at the moment. I will try to remember to post here when I do complete it.

[JohnB]

I have all the parts here and will be doing it soon, with as many photos as I can take! I am not sure precisely when, as I am busy removing things at the moment. I will try to remember to post here when I do complete it.

Thanks Jeemy, I look forward to your post.

What is confusing me is the connection to Pin D7 on the ECU connector.
WikiLEC says :-
4. Disconnect the battery, return to the passenger footwell and unplug the ECU harness from the ECU. Connector pin D7 can be located using the markings on the connectors. The wire from this pin should be spliced to the footwell end of the signal wire.

When I compare the Open Loop and Closed Loop wiring diagrams there is a D7 terminal shown on the Closed Loop diagram but not on the Open Loop. So, will there be a wire connected to the D7 terminal on an Open Loop system to splice to, or will it be an empty pin?
Am I missing something?

[cliff]

I did mine a few months ago and didn't have any problems apart from the usual lack of space.

On some cars, the wiring is missing between connectors RHFHC and MHC, check the wiring on your cars first though, you might be lucky.

O2 Wiring.jpg

I wasn't lucky, so inside the car, there was a wire going intothe ECM pin D7, I spliced into that and added the wire at IPHC A15.

In the wheel arch, this is the grommet you need to push the wires through.

CIMG1203.jpg

This is the the RHFHC plug.

CIMG1202.jpg

I didn't have the correct pins for the plug so ran the wires near to it, found the wires than go to the O2 connector and spliced into them as per the wicki & diagram.

I would advise the use of a good quality sealed splice in this area. I used these.

https://www.edmo.com/index.php?module=p ... d_id=18889

Conrad do something similar.

http://www.conrad-uk.com/ce/en/product/ ... Detail=005

Hope this makes it a bit clearer. Lots of info on this thread as well

viewtopic.php?f=33&t=13359&hilit=closed+loop

[JohnB]

Cliff, thanks for the info.
My car doesn't have the necessary wiring so I'll have install it.
Still a bit confused though. If, as with your car, there is a wire coming from the ECM pin D7, what is that for, because ECM pin D7 isn't shown on the Open Loop wiring diagram as far as I can see. Any idea?
Cheers John.

[cliff]

Not really sure but D7 is shown in the Engine Management manual as not used.

Pages from Elan M100 Engine Management Manual v6.jpg

The other unused positions are just left blank so maybe D7 is there for use in other applications or markets. If the wire is there on your car then happy days, a bit less work to do, just need to fill in the gaps.

[JohnB]

Hi all.
Still not got around to doing the closed loop conversion, bit cold in the garage at the moment, but I've got all my bits together ready for the attempt.
What I've done is to get the multiblock plugs for the ECU end and the connection under the O/S wing from a scrap yard so I can put the proper pins into the existing multiblocks to make the connections as they would have been if the wiring had been installed at the factory.
What I don't understand is, and I hope someone can help me, looking at the scrap yard ECU multiblock which is from a 1991 SE, at pin D7 there is a green/grey cable connected to it. On the wiring diagram below it shows this pin as not used so does anyone know what this is wire for? On the WikiLEC instructions it says splice to the wire coming from Pin D7 so it appears there should be a cable there but why?
Any help would be greatly appreciated.