Superspec Emissions Failure

[Longboarder]

Does the ECU store fault codes that you can read? That might be helpful.

[alanrichey]

Yes, and I don't have any And with my software package I can see that the lambda sensor is working as per specification.

 

Basically the problem is that in the early 90s, it seems the Rover engineers hard-wired the ECU to control the fuel mixture, based on the standards at the time. We Superspec owners have to meet the standards as defined on our SVA date (generally 2005-2008), which are a bit more limiting. At the time of the SVAs no-one had any proof that our engines were built in 1995 to allow them to use those limits. And with the demise of Rover I doubt we could find anyone to re-categorise our emission standards to the earlier date.

[deano266]

what about restricting fuel flow for the MOT by having a pipe tot he fuel filter with a few inline filters in it

[alanrichey]

My lambda reading showed the engine was running too lean, so I don't think restricting the fuel flow will help.

[brumster]

When you're tweaking for emissions, you really do need exactly what you say - a gas analyser and the ability to tweak the fuel map live. It's not necessarily the case of making it as lean as possible - you lean it off to much and you get unburnt fuel and your hydrocarbons go through the roof. You can also fiddle with the ignition map a little, I found this didn't really achieve as much as I thought it would, but maybe it's different from one engine to another. Probably of more use on the idle test, rather than fast idle.

 

I found that once I had addressed the air leak in my exhaust, getting it on the money in terms of the emmission requirements was pretty easy.

[geordie40]

Hi Alan

 

Wow it did just scrape through.

 

This is what mine passed at

 

Fast idle CO 0.20% max 0.01% actual

HC 200ppm Max 7ppm actual

λ. 1.03 max 1.004 actual

 

Natural idle CO 0.3% Max 0.01% actual.

 

Would a mems diag scan on mine help any as mine seem very low in comparison. Also when mine failed and emissions were through the roof it turned out to be the throttle potentiometer, not sure if thats same as throttle position sensor as that was error I had in the mems log.

 

I was told if potentiometer wasn't working correctly the ECU couldn't control the fuel mix, I also had an iffy temperature connection, not the one for the temp gauge but the one for the mems, it was only reading 5 degrees so again ECU thought engine was cold.

[deano266]

On mine my iat is reading faulty too geordie although mine is stuck at 42

[alanrichey]

This is what mine passed at

 

Fast idle CO 0.20% max 0.01% actual

HC 200ppm Max 7ppm actual

λ. 1.03 max 1.004 actual

 

Natural idle CO 0.3% Max 0.01% actual.

 

Wow, they are superb figures. I wish I knew what your builder did to achieve that. I wouldn't mind a MEMS Scan log file just in case I can see any difference.

[geordie40]

Hi Alan

 

Is it best if I create a log file with engine cold and another one with it properly warmed up and how long should i leave it running for?

[deano266]

what type of cat are you running for the MOT. could it be that its just not effective enough at taking out some of the hydrocarbons and CO.

[alanrichey]

Hi Alan

 

Is it best if I create a log file with engine cold and another one with it properly warmed up and how long should i leave it running for?

 

Just the next trip you take. That covers all the bases.

[alanrichey]

what type of cat are you running for the MOT. could it be that its just not effective enough at taking out some of the hydrocarbons and CO.

 

Just the standard cat that came with the kit. But remember the cat is to remove the hydrocarbons, and that wasn't critical. The CO is controlled by the lambda sensor and the fuel trim. So that is where I need to concentrate my efforts.

[Longboarder]

Might be worth checking what sensors Geordie is using. Very specifically exact part numbers of each engine/load/lambda sensor that can be identified and if he has more or fewer sensors in operation. ie MAF,MAP or TPS for load, etc.