High emissions

[robin]

Unless you know for a fact that the ECU has had some sort of trauma I would be amazed if your problem was ECU.

It's possible to test the coils with a multimeter (not 100% reliable but better than just swapping them on the off chance).

The air filter, if really really bad, could have been a factor.

I suggest removing the spark plugs first and compare them to one another. If they're all uniform in colour then your problem is more general; if they are different colours then we're looking at cylinder specific faults, possibly.

[Scuffers]

I suggest getting the full emissions test results so we have a clue what the problem is...

[robin]

Agreed that it would be useful to have some facts ...

[Guidedog]

who am i to argue. thx fellas.

.gav.

[KingK_series]

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

Possibly, but the green Viton manifold gasket from post '98 cars - ie all S2's very rarely goes, the earlier gasket was rubber rather than Viton and did degrade with heat, which was why the spec was changed.


OEM ecu's do go down, in my experience - and suddenly=y without warning , I've sent OEM ecu's for diagnosis on the Longbridge diagnosis rig and seen completely fubared ecu's - the manufacturer[ ecu manufacturer that is] would not guarantee them beyond 100,000 miles, though clearly the majority will last well beyond that.


I can point you to a source of OEM ecu's tested with a non "made for granny ignition curve' which will feel noticeably quicker -

[robin]

The S2's ECU is not related to Longbridge ... the K4 VVC ECU appears to break, usually when the battery is put in backwards, but I've yet to see a bust K4 K16 ECU that hasn't been caused by water ingress.

Cheers,
Robin

[KingK_series]

The S2's ECU is not related to Longbridge ... the K4 VVC ECU appears to break, usually when the battery is put in backwards, but I've yet to see a bust K4 K16 ECU that hasn't been caused by water ingress.

Cheers,
Robin

The Rover eu4 ecu's I have seen fubared seem to have worked fine until it suddenly just didn't - no water involved, the manufacturer - can't remember who it was - remarked to the dyno jockey guys at Eastworks that I know that they expect/cannot guarantee/see failures after 100 klicks worth of use - nothing exact they were apparently just aware of a percentage of failures after so much use and expected it .......

which is weird because all the electrical engineers I've ever worked with seem to expect electrics to fail immediately or have more or less indeterminately long life ..

[sanderb]

which is weird because all the electrical engineers I've ever worked with seem to expect electrics to fail immediately or have more or less indeterminately long life ..

It's not a simple as that. I.e. Elcos specced at their maximum temperature will degrade faster than they normally do. They will lose capacity over time. Same for tanatalum capacitors. This is why for allot of electronics i.e. settop boxes and TV's there are known fixes for certain fault conditions.

[robin]

Correct, and temperature makes a huge difference to this too. So an ECU that spends its life at 125C on a race track will wear out the electrolytic capacitors much faster than one that does its miles more gently in a colder climate. The ignition drivers and to a lesser extent the stepper motor/relay drivers also "wear" out - each activation of the driver causes a reverse current flow that is dissipated by the driver circuit one way or another. Particularly for the ignition drivers this is a so-called avalanche discharge and although they are avalanche rated, they are only rated for so many (million) cycles ...

We avoid using electrolytic and tantalum capacitors for this very reason - modern ceramic capacitors are fine for all things digital and most things analog Luckily we don't drive any inductive loads so no problems with avalanche ratings!

Cheers,
Robin

[sanderb]

I only let my engineers use tantalum in exceptional cases and elco's need to be derated regarding capacity, voltage and temperature. (I work here: http://www.rommtech.com)

[Guidedog]

So... turns out if you clean your air filter, your carb, change your HT leads and ignition cables to Magnecor V85 Competition ones, clean your butterfly, open your throtle and generally speak nice to your car you dont have to worry too much about your ECU or indeed your cylandar head gaskit.

Go figure.

Still.. I have a fab new sports exhaust and new cat and my sensor if still shiney.. Massive plus. the car is running like a dream, sounds awesome and has made a full recovery.

thanks for all input.



.gav.

[SAJ]

Try this: http://www.demon-tweeks.co.uk/Product.d ... =Additives

[robin]

Glad you got it fixed. For the benefit of anyone who finds this thread later, your car does not have a carb (nor does any Elise) - you may have cleaned the IACV though?

Cheers,
Robin

So... turns out if you clean your air filter, your carb, change your HT leads and ignition cables to Magnecor V85 Competition ones, clean your butterfly, open your throtle and generally speak nice to your car you dont have to worry too much about your ECU or indeed your cylandar head gaskit.
.gav.