Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing NOT fail on emissions

Ok...
The numbers show you’re actually lean, possibly too lean, hence the unburnt fuel pushing the HC and the CO up

That should be adjustable on the airflow meter....

Teknome, I don’t have that much info

I do have one of the diagnostic cables that plugs into the ecu and a laptop, plugging that in tomorrow. Will it throw up any of the above info?

Simon, I assume it’s adjusted via the small screw in the photo above?

Thanks for all the help chaps, much appreciated

Gary

Regarding the MOT limits - the emissions machines do a BET "basic emissions test" first. Most cars usually pass this. If these basic test readings are not met however the tester has to select the correct listing from the data-base - this is the "in service emissions" list mentioned. This sort of widens the goal-posts in many situations and can assist with passing. Some testers select the wrong listing which doesn't help! Over my years of MOT testing, with the Rover V8 engine ( in land-rover products mainly) i have found it helps to make sure the engine ( and exhaust cats ) are really really hot. Often range rovers of early 90s vintage seem very marginal on emissions - revving them usually scrapes them through.

Old petrol doesn't help by the way either - we are seeing this lately with cars that have sat more idle than usual due to this years restrictions. Odd emissions readings and poor running etc.

Not been able to get to the car today - fitting kitchen for the management!

Managed to get some injector cleaner as recommended by mot tester (might help, might not). He say he can get it on his gas machine next week and have a fiddle with that adjustment screw. Test report shows longer cycle on second run - still failed.. oh and I’ve bought one of those rubbish Chinese MAF on eBay as a just in case idea.

Hope to get a run out tomorrow but lockdown is a problem now and having failed an mot I technically can’t drive it Other then for a re-test.

Fuel is fairly recent, I’ve done a couple of hundred miles in the last month.

Cheers all

I was advised injector cleaner and cat cat cleaner work best when put in a near empty tank (makes sense)
Give the car a good run to make sure the fuel gets to where it needs to be to do the work. I guess even fast idle running would help if you can't get out on the road.

I’m wondering if I can use cat cleaner and injector cleaner at the same time?

My Plus8 with Gems has always shown as marginal on Lambda readings, usually near top end. In 2018 it needed getting plenty of heat into the engine to pass. Previously a mate used to take my car to where he worked as MOT tester and he advised trying cat cleaner. I did, on a low tank to increase concentration. No before/after results though so the effectiveness was not measured.
Last year the car went through ok with no issues. I have since put heat shield round the cats so hopefully that may help in future. Maybe exhaust wrap at some stage too to help getting the cats up to temperature.

Many moons ago a very well known Morgan racer told me to use Marvel Mystery Oil in every oil change and in the fuel tank on every other fill or so, so I have for the last 30 years. In my 94 +8 at just over 65,000 miles the engine internals look as good as new and never had a problem with any sensors or injectors, just once using carb spray to clean the airflow meter.

managed 30 miles today ( had to take some stuff back to B&Q and as we don't have one in my Unitary Authority I had to cross the border to England before it shut at 6.00pm tonight!)

The injector cleaner might have made a difference as the idle felt a little smoother on return home following a spirited drive, placebo??

I use fortë injector cleaner and cat cleaner at the same time. My MOT tester calls it snake oil but it seems to work in my engine. One MOT I put it in just before the short but high rev run to the test center, emissions test first, it looked set to fail but in the last few seconds before the end the figures changed dramatically and it achieved a pass well within the parameters. I now put it in well before the MOT date.