Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing GDI valves and cat cleaning

There have been some threads that have caught my eye

One about CRC GDI valve cleaner CRC Valve Cleaner

and another regarding Cat Cleaner Cat Cleaner

My Plus 4 GDI has done 25,000 miles
Not long after I purchased the car I replaced the exhaust manifold and cat with one from Librands, probably the best thing I have done as it transformed the engine.
Other applicable mods are Dave W's breather modification
and his wrapping of the air intake pipe with heat shield

But in recent months I have noticed a developing hesitation a bit like someone lightly applying the brakes, Also an increase in the pops and bangs when taking the foot off the accelarator and coasting.
When cold I have to be a bit more aggresive with the revs and get caught with Kangarooing sometimes!

So far I have
Changed the plugs, there were rather black, but no percived difference
Swaped the MAFsensor but no percived difference
Changed the air filter, now that did improve things but not cured

So now I'm thinking of using
Catacleam for petrol this is just a pour in the tank when about a third full
and possibly
CRC GDi cleaner

But would be interested in other forum members ideas.

There is also a new spec oil now to help with the GDi problems. Just bought some ready for the oil change.

Ian

I'm pretty new to Morgan ownership but here is a random thought from my recent experience. If you are getting the hesitation particularly when pulling away it may possibly be a rear brake binding - I say this as 6 months ago I found I was needing more revs to pull away in my P4 (it has the Clubsport full exhaust and remap 18 months ago which has been an excellent improvement) and occasionally kangarooing or even stalling once or twice and the car also felt a bit sluggish at normal driving speeds. A bit embarrassing really, but it didn't occur to me it was a binding brake until I burnt my hand on the centre nut cleaning the rear wheel after a longish run! It was fixed quickly by the dealer just within warranty and has been fine ever since.

Regards

If the plugs were black that indicates the mixture is too rich, Consider Lambda sensors.

AlyMatt,

I have now removed the K&N filter out of the housing and removed all of the pipe work so the filter now sits in free air and the hesitation has now gone so looks like it was not getting enough air.

Ian

Binding rear brakes is an idea, I did try checking temp on each drum with an IR point and shoot sensor after a decent run, but need to do it again a few times to come to a conclusion.

If the brakes are binding, you won’t need any hi tech devices to measure temperature. A hand on the hub or spinner is all that is needed…but be prepared to get burnt!

Just to add to the brake binding theory; when I took my GDi to Techniques for it's first service (Techniques were my nearest service agents) they re-routed the rear brake cable which had been causing the rear brake to bind ever so slightly. I was amazed at how much livelier the car felt immediately and the fuel economy also improved.

Tim, check out this thread, including my video of removing the intake manifold. You will then be able to clearly see whether the valves need a proper cleaning or not!