High emissions

[Guidedog]

Hey gang,

Gav here. Gotta question for you all about ECU's. Been having soo much fun with mine...

Been a tale of woe with my Elise just recently having failed my MOT on emissions. Replaced the CAT which was seized to the exhaust so forced to buy a shiney new sports exhaust. retested.. still high emissions. changed lambda sensor.. retested.. still high.. Thinking ECU but kinda reluctant having been bitten by jumping in too quickly as previous. Is there a chance that a remap could sort the ECU or is there anything else I could do or test before I bite this particularily nasty bullet?

yours lovingly

.gav.

[robin]

Is it S1 or S2?

Is it more-or-less standard?

Unlikely to be ECU - more likely to be misfire or vacuum leak in intake or exhaust somewhere.

If it's S2 then the answer will most likely be in the OBDII live data readings which you can get from any reasonable garage. I would take it to MMC for diagnosis and if it's S1 realistically it needs to go somewhere that has MEMS1.9 diag (or LotusScan tool).

Cheers,
Robin

[ikarl]

have you seen the episode of Wheeler Dealers where he uses a 'Terraclean' system on a Jag XK8?

if not, google it.... I just looked about the internet for 5 minutes yesterday and was very surprised by the results people are posting. I don't know how it does it but apparently it cleans the whole system of carbon and in most cases easy allows a pass

ETA - Robin's answer is much better than mine. I'll get my coat

[Guidedog]

Hi guys thanks for quick response. S2 Robin 51 plate. thought it could be a misfire but not exactly sure how to diagnose this (until now). MMC sounds like a good option.

Thanks Robin.

karl.... You tried God love ya.

[robin]

The ECU will know it's misfiring and store a code - as it clearly effects emissions is ought to light the MIL too which might then be an MOT fail anyway (not sure if that was ever actually introduced, though).

As S2 have plug top coils you get a lot less HT failures than on S1 (king leads, rotor arms, dizzy caps, exposed HT leads all fail from time to time). Total coil failure would have it running super rich and 50% power so unlikely to be that. Individual spark plug failure is possible and will be recorded as a fault against the specific bank, with luck, as the ECU will know which bank is misfiring. Is it losing any coolant?

Cheers,
Robin

[Guidedog]

Robin.. You may well be a Jedi Master as advertised. Collant level is down. No fault light currently and codes checked couple of days ago. Had code failure but this no longer showing.

.gav.

[robin]

I think it's much less common of an issue on later engines (i.e. as fitted to S2) but you could have a leaking inlet manifold gasket that will allow coolant to weep into the cylinder bore. This could cause a misfire, depending on how much leaks. If you remove all the spark plugs and one or two are shiny and clean whilst the others are the normal burnt sandy/brown colour then you have coolant entering the bore somehow - either via the inlet manifold gasket or some other problem with the head or head gasket.

Cheers,
Robin

[Scuffers]

would help if the actual test numbers were posted up, hight means not very much without the numbers...

looking for CO, HC and Lambda...

[Guidedog]

001 Exhaust emissions carbon monoxide content after 2nd fast idle excessive [7.3.D.4]
002 Exhaust emissions Lambda reading after 2nd fast idle outside specified limits [7.3.D.4]

All Dutch to me but Im certain its childs play for you guys. thanks for input.

.gav.

[robin]

Did they not print some actual numbers on the fail sheet? Might be on attached emissions printout.

Anyway, looks like it's running rich as CO is high; though not always the case, this tends to suggest a misfire rather than an air leak.

Cheers,
Robin

[KingK_series]

Did they not print some actual numbers on the fail sheet? Might be on attached emissions printout.

Anyway, looks like it's running rich as CO is high; though not always the case, this tends to suggest a misfire rather than an air leak.

Cheers,
Robin

Exactly

so if you are losing coolant and the engine is missfiring [?}{does it sound rough?} the chances are you have cooked the head need a new one -????

- beware of dealers/garages diagnosing "HGF" - it's not the gasket that fails.

[robin]

Not to mention it could merrily be just the inlet manifold gasket ....

[Guidedog]

Its a bit like Triggers broom this! It would be exciting if it wasnt so expensive. Nope no numbers readout. Even warm the engine has habit of stalling if this is another clue for you fellas. Definately got some leads to follow up this week.

thanks as always.

.gav.

[Scuffers]

001 Exhaust emissions carbon monoxide content after 2nd fast idle excessive [7.3.D.4]
002 Exhaust emissions Lambda reading after 2nd fast idle outside specified limits [7.3.D.4]

All Dutch to me but Im certain its childs play for you guys. thanks for input.

.gav.

not that, you should have been given a printout from the test itself, the pertinent part looks like this:

[Guidedog]

hi guys.

Have had a good root around today. Took the airfilter off and amazed at how dirty it was inside. (must clean filter). Had a look on Elise Parts and priced up new leads and coils. £189.00. All well and good then got cold feet prior to pressing buy as I have a niggling thought that I really should check the ECU first. I know this might be a wild goose chase and ultimately I will be purchasing the kit anyway or heaven forbid changing the cylander head gaskit but might there be anyone out there who could give me a loan of their ECU so I can remove it from the equation?

Thoughts as usual appreciated.

.gav.