MOT Emissions

[kris450]

Managed to get an MOT done earlier and some interesting emissions results...

For reference car has been laid up for a couple of years. New rebuilt V8D engine just gone in (not fully run in yet and on running in oil), original CAT y-piece fitted for Mot (appears to be in good condition) but no precats and Bosch 0280156045 injectors fitted (as recommended a few times on other posts on here).

As far as the data from the Mot guys goes, the Fast Idle and Natural Idle CO readings should be max 0.30% and 0.50% respectively.

My readings are 6.66% and 1.59% respectively... What the funk !!!!

Any usual suspects to look at first ? MAF, temp sensor, etc ?

I'm limited on diagnostic kit and time so wondering if I should just ship it off to someone who actually has the experience, as sadly I'm leaving my comfort zone here.

[ridds]

What were your lambda and HC values?

[kris450]

ridds said:

What were your lambda and HC values?

Looks like:

Lambda - 261ppm (max allowed 200ppm)
HC - 0.81 (range allowed 0.90-1.10)

[rigga]

How hot was the engine when tested ?

[kris450]

rigga said:

How hot was the engine when tested ?

As hot as we could get it without setting it on fire !!

To be fair to the tester he's mot'd a number of Tvr's and new all the tricks. Sadly he couldn't let those figures go of course !!

[ridds]

kris450 said:

ridds said:

What were your lambda and HC values?

Looks like:

Lambda - 261ppm (max allowed 200ppm)
HC - 0.81 (range allowed 0.90-1.10)

It'll be this way round:

HC - 261ppm (max allowed 200ppm)
Lambda - 0.81 (range allowed 0.90-1.10)

Your Lambda reading is stonking rich, which isn't good at all. It needs to be as close to 1.0 as possible. This is likely the bulk of your issues.

That ppm level against the Lambda suggests the Cats are converting but are struggling (not surprisingly) with the over-fuelling,

[Strudul]

When I had high CO readings it was due to a faulty lambda sensor.

Can you connect up RoverGauge and monitor?

[kris450]

Strudul said:

When I had high CO readings it was due to a faulty lambda sensor.

Can you connect up RoverGauge and monitor?

Sadly not. Don’t have the time or equipment annoyingly. I don’t even own a laptop haha.

Just called and it’s off to Str8six at the end of next month. They’ve looked after the car for ages and as I said I’m out of my comfort zone now.

Cars been off the road for a couple of years so I can wait a few more weeks !!

[spitfire4v8]

What ridds says ^^

either you have a faulty lambda or associated circuitry meaning there's no mixture control, or you have enough of an overfuelling issue that the lambda trimming can no longer compensate ..

str8six will be able to diagnose and fix that no problem.