Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Roadster on going P0171 & P0174 ECU faults

John, this is the worst place where your airbox could break. The way it looks, you have unfavourable turbulence and possibly backflowing air right where the MAF seonsor is placed. You should repair the air duct there at the MAF sensor in a very round shape and very smooth. Or you might need this part new.
Regardless of possible leaks, I wouldn't be surprised that the wrong values were caused by a completely irritated MAF sensor.

or to say it positively, I'm convinced that after the repair your car could run like transformed.
I think you know the following anyway, but just to repeat it, I would remove the MAF sensor before you work at this point. And of course clean everything thoroughly afterwards so that nothing is sucked into the the engine.

I know. I doubt you can get a new one as they were specially made for MMC.
The design is bad as the engine moves with the filter box attached to it the forces are focussed on that part.
I might fit an induction kit but will try the rebuild first.

John- the device you use to clear the code each time is doing it properly is it, and not letting you chase your tail by leaving the error code there?
Sorry not meaning to be rude or anything, just I had a mate once with a Mitsubishi had that happen.

It seems to. If you go back in there is nothing either pending or active.
The airbox has "chattered" a lot looking at the fibreglass & I guess it moves & air leaks in after the MAF. I will try to repair it on Monday.

I am considering ordering a K&N induction kit as belt and braces as it replaces the MAF holder but of course the filter is in the hot zone of the engine. Has anyone done this?

John, to help with the fibreglass repair...

If you expand a large jubilee clip to a tight fit inside the damage then use that to wedge an old credit card under the area of repair it will both re-form the distorted circle and give you a surface to work the epoxy liquid too, when dry the card should just ping out

Well today I repaired it and no more fault codes so far.


Jon M thanks for the tip on the credit card that really helped.


I also fixed washers to the holes in the airbox that fix it to the engine & were showing signs of chattering.



Whilst the box was off I fitted some petrol pipe around the breather hose that rubs on the hoisting bracket on the engine.



The only T piece I could get was plastic but I have a brass one on order from fleabay.

It is surprising how a bit of air in the wrong place can cause so much havoc.
Well done for getting it all sorted
I wonder if the GRP Airbox on the early Roadsters will be a bigger issue as they age? As far as I know it is unique to MMC.

Peter I think so. It is not well made or well secured.
I did look at a K&N induction kit but at nearly £200 and the filter being next to the engine & with no cold air feed I decided to persevere with the repaired unit .
You can buy bit on line to create your own, so that may be a route if all else fails.

Very good job! Congratulations, John. I am wondering if some hard rubber washers (if heat is not a danger at this position) in addition between the box and the engine could help to absorb some of the engines vibrations and protect the airbox
...or would those rubber washers only add uncontrolled and more violently swinging vibrations, I do not know but I would try ist.

Heinz,
I know what you mean. The bolts that screw onto the engine have penny washers & then rubber washers between the bolt head and the outside of the box. You can see them in the 5th photo.
That is all that secures the box apart from the hose. An upper fixing might help to hold it better.