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

My S1 Roadster with the ST220 engine continues to have this fault though recent actions now mean it stays as a pending fault for far longer. But it has been getting worse with lumpy idle etc

I have replaced the seals on the fuel cover cap. I also replaced the fuel cap which helped significantly now the fault was triggered after several drives not just starting the car. But it was still there.

Ford forums suggested it could the breather pipe from the PCV valve to the UIM. I had already inspected all the hoses on the vacuum side and tried the old spraying carb cleaner around with no effect. Anyway I bit the bullet and flashed the cash of fleabay.
https://www.ebay.co.uk/itm/CRANKCASE-BREATHER-HOSE-PIPE-FOR-FORD-MONDEO-ST220-4461858/323806515049?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

The old hose looked OK. But the replacement helped on the poor throttle & the car was transformed but the ECU fault was still there.

When I checked again all the hoses I saw on the underside the hose from the valve that releases vapour from the fuel tank was perished. Overall it is stiff & brittle.


Tonight I used gaffer tape to wrap the hose and the fault is again reduced & the car even smoother and swifter. But the gaffer tape slips off due to the engine heat
Thursday I will fit a piece of 5/16 ths hose.

Fingers crossed.

John, hope you've finally found the culprit

Sadly not. There must be another leak somewhere. But the car is running better

I cleaned the IACV this morning. I seemed quite stiff so I have ordered a replacement.
If / when that doesn't work I am going to a garage.

I read in a German Ford forum, that the same error codes were solved when replacing this tube on a ST220...after long search. It looks different to the one you have changed, John, it is the feedback loop to the intake.

https://www.ebay.co.uk/itm/Genuine-Ford-Mondeo-MK3-Air-Box-Connecting-Tube-4940144-/272379843724

may be it has different length in a Morgan due to the different positioning of the engine in the car but it could be principally a further candidate to be the culprit when it is not sealed any longer and the engine sucks additional air which was not calculated.

Heinz, thanks for that I have two of those joining at a T piece. The airbox is different to the Mondeo as is the hose to the throttle body. Hence the t piece I guess. Tomorrow I will disconnect them & put a circular pipe on the T piece to see if the fault goes.
The IACV arrived today & that has made the idle smoother but the underlying fault is still there.
Next step is to take off all the hoses & the filter box to recheck them for leaks if the test Sunday fails..

The saga continues I decided to make a start taking off ever hose & checking them.
When I removed the hose connecting the airbox to the throttle body it showed that the fibreglass had deteriorated & broken apart where the jubilee clip fits.

I hope that is the culprit and will get a fibreglass repair kit tomorrow to work on it.
Also the plastic T piece into this hose for the breathers Heinz referred to was brittle and broke apart so I need a new one of those as well. I 'll get it in copper.

And a better photo of the failure

Hope you now have the answer John

So do I. The problem is the airbox vibrates a lot due to the way MMC fitted it.

Hopefully next week we will see a result.