emission test failure, 400 pre-serpetine, cat-model

[Chimp871]

Maf and throttle numbers look OK.

Lambda trim try on long term and see what happens (or swap sensors as blitz said).

If fuel, water temp sensors haven't been changed worth buying new as they're under a tenner each and can make a difference.

Ditch extenders get silicone boots.

Check rotor arm and its clean as well as dizzy contact points.

Probably work checking the MAF for good measure, there is a way to check this without buying another (same for the sensors too if you can be bothered) blitz/g33 believe did a write up.

Very hard to know if its working though without a trip to the mot station to be probed. Friendly mot test centre would be a good idea, at least you can get your car up and running to do more fault finding.

[LLantrisant]

car has been taken off the road, exported, now in process of re-registrting in his new location.

technically the car passed local MOT, but new reg-documents cannot be issued as long as i do not bring a valid emisson-test certificate, hence car is not road legal and cannot be driven , even 1m, on a public road.... i have now 3.5 weeks left to bring the certificate, otherwise the MOT test will expire and i have to do all again.

back to the car:
i´m still waiting on mr. dpd-man bringing me a pracel with the special socket for removing the oxgygene sensors....and mr. dhl-man a parcel with 2 new oxygene sensors.

temperature sender was changed 1 year ago (invoice found in folder), MAV 2 years ago, but the rotor and cap is also a good advice, as those are the only parts in the ignition system which i havent changed.

Edited by LLantrisant on Tuesday 20th November 10:59

[blitzracing]

If you have a deep socket that will fit over the probe, you can cut a slot with an angle grinder to allow for the wire, then pop a hose clip over the base of socket and tighten it to stop it expanding. The probes are smaller than your run of the mill ones, so the standard tool is too big.

[FoxTVR430]

You can do what blitzracing has suggested or you can remove the pins from the plug, then slide a hollow hex socket over the cables down to the lambda probe in the exhaust manifold.
Here are some photos I took during the process.



I used a thin screwdriver to release the pins in the plug.








I needed to remove the rubber bung to get the socket over, cutting slowly to remove each wire.

[LLantrisant]

great advise.....but the socket is already in order....and 25,-€ do not hurt....;)

[LLantrisant]

finally my lambda-probe socket arrived today....changed sensors within 5min...connected rover-gauge and here we go:

when engine is warmed-up and lamda-probes start to regulate, they are "dancing around" zero on both banks...depending on throttle position. long-term trim shows zero.

looks like we have a result? (provided the CO-& HC readings would have improved too, but i can already "smell" a difference on the exhaust)...what do you think?

by the way i checked also dizzy-cap and rotor: they are new (i had them replaced , but didnt remember)


short term




long term:

[LLantrisant]

borrowed an old emmission tester from a mate:

2500rpm: 0,1% CO

when going down to idle-speed CO readings went up to 0,4 for a few seconds b4 going down again to 0,1-0,2%

[LLantrisant]

today it was the time for the "offical" emission-test: car passed!!!!

what i want to mention is:

i have thrown-out the TVR-recommended spark-plugs (the ones with recessed electrode) even they had been only fitted since a few weeks & had around 50miles on the clock and I fitted "standard" plugs:
better start
smoother idle
smoother acceleration
in general a more stable engine run