Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing 2012 M3W rough running

I, perhaps foolishly, drove my new toy 1300 miles from San Francisco to Colorado Springs. Had no problems other than getting surprised by quantity when fueling. 8.2 gallons at one fill-up provided a scare. I must have been running on luck instead of petrol. I'm now resetting the trip meter at fuelings. It's a more reliable gauge of remaining range than a 0% fuel reading.

After getting home, I experienced a hiccup that momentarily affected power. Engine light came on briefly. DTC history: P0170 P0173 P0217. The latter no doubt occurred while idling through East Bay traffic, escaping to the east toward home.

Then, I took a cruise with some motorcycles during which the previously experienced hesitations occurred multiple times. Eventually, the check engine light remained lit. Got home without any truly frightening symptoms.

The active DTC is P0170 Front Adaptive Max Limit. In the history is possibly the cause, P0134 Front Oxygen Sensor No Activity Detected. Because the car is 6 years old, I think it is reasonable to suspect an oxidized connector.

I suspect that the front cylinder on a Harley clone is the same as the front (port side) cylinder on the Morgan. Being a lazy individual, I'd like to limit my efforts to most likely fault. So, I'm asking you experienced M3W tinkerers to confirm that the front cylinder is indeed the one on the left, viewing from the cockpit. And, if there's a most likely culprit, please point me to it. I assume that the firewall needs to come away to facilitate access to most connectors? If the O2 sensors are so frail that it is actually more likely to be the culprit than a connector, that would be helpful information as well. Current odometer reading is 6,671 miles.

Thanks for the help. User forums like this are incredibly valuable. They've guided much of my motorcycle troubleshooting. I try to give back by sharing my experiences.

Did that happened immediately after refuelling, if so the tank was overfilled just fill the fuel tank until the pump stops but then do not top off. Most of us have had that happen.

The front cylinder is the one on the left sitting in the three wheels

the electrical sockets of the lambda probes are normally waterproof (Deuch or Amphemol)

verify with Protune the occilation of the voltage of the lambda probes (0.5 V to 1.1 V approximately)

to make a reset of the ECU adapter map

sealing of the air intake system to see

good luck in your research

Actually, yes it did. I wrote off the initial bogging as too much overflow fuel in the canister. Had the same problem with my MotoGuzzi V7 before their check valve recall. But when the symptom persisted intermittently for, say, 60 miles, I assumed that something more sinister was afoot. I confess, topping off has been my compulsive habit for 55 yrs. Thanks, Rog G.


I didn't try ProTune with the engine running. Thanks for the suggestion, GLLOQ. Thanks, too, for confirming that front is left. I didn't think that the ECM system would allow resetting or adjusting much other than DTC history. This is all new to me. Could you elaborate a little?

I have had it happen a few times and it usually clears and runs normally after a couple of miles. However one time I refuelled and left the car on a slight slope overnight. The following day the engine was difficult to start and ran rough for at least 50 miles with engine light on, I stopped and restarted again after 30 minutes, still the same, drove another 5 miles stopped for lunch, restarted and the engine light had cleared and was running smoothly again. That was about 4000 miles ago and its been fine since.

My MotoGuzzi V7 was very finicky about topping up. It would barely start moving after any over-filling of the tank. MotoGuzzi had a recall for this system in which they replaced a check valve. My assumption is that the replacement valve included a smaller orifice so that sucking the vapors out of the canister didn't upset fuel mapping as much as with the original item. Maybe a consideration for Morgan?

MotoGuzzi dealer gave me the option of installing the check valve on the recall or relocating the system. I went for the latter. It consisted of locating the vapor recovery bits in a shopping bag and handing it to me. No more trouble from topping up, but if I had it to do over, I'd have opted for the repair. The system is for reducing atmospheric pollution. I have no argument with that, as long as the implementation doesn't cripple the vehicle.

I cleared the adaptive maps and the fault history. Lambda readings, front & back, were in the neighborhood of 0.73 V and very reactive. Looking good. Thanks so much to you, GLLOQ and Rog G. User forums like this are fantastic resources.

I put everything back on and went for a brief spin. I f*g love this crazy car.

Apparently, I had something other than over fueling going on. With laptop on passenger seat running ProTune, within a couple of blocks, the O2 readings were beginning to look strange. After several blocks, the front sensor went to 0.00 and stayed there. Suspecting the Deutsche connector, I hit the contacts with DeoxIT D5, cycled the connector a few times, and tried again. No change. I wouldn't have thought a lambda sensor would die with 6,400 miles on it but it is, I presume, 6 years old. Naturally, I have active trouble code P0170, front adaptive max. What I don't know is a lot. I don't know whether to expect a high O2 voltage reading or a low reading with a failed sensor. I don't know if there are multiple failure modes likely or possible.

I left this thread hanging, didn't I? Sorry. Three years ago, I contacted Bill Fink who advised me to swap O2 sensors, side-to-side. If the code changes, it confirms a bad sensor. This worked and a new sensor cleared the engine fault light.