Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Engine Light and Rattle

I am posting for help with two problems on my 21,000 mile 2017 5-speeder. They may be a coincidence or connected.

For the past few months it has sounded increasingly rattly, as if something is wrong with valves/tappets/rockers. It ran fine however and I put it down to the fact that they do get louder as they age. Then one day the sound started to disappear suddenly at c 3,000rpm. Above that it pulled well and the engine became unusually smooth!

I have checked under the rocker cover and looked at the cam belt (which I changed last year) and there appear no problems, although it is getting louder.

More recently my engine light has been coming on with the faults PO170 and PO173, which are both left and right cylinder "adaptive max limit". I have the Morgan 3-Wheeler Diagnostics Software v1.4 and have been able to clear the codes and reset the adaptive maps, but the faults come back together after another ten minutes driving. Logically, that would suggest a fault common to both cylinders.

I have put on a new Throttle Position Sensor and set the resting voltage to 0.5 volts, and cleaned all the other engine sensors. Fuel pressure is reading 54 psi with ignition on and engine off and the pump sounds vigorous. The air filter is fine and there seem no air leaks. I have ran the "test outputs" on the software and it shows no faults.

The car started its life with a Euro 4 ECU but Morgan swapped it back to Euro 3 under warranty. That disabled the OBDI connector, so I can't check that.

It still starts but is rough when cold, rattles like crazy then the engine light comes on.

Any suggestions gratefully received on what may be causing the problems and how I might diagnose them further. Cheers. Geoff

Check for particles of rubber in the bellhousing/centa.

Hi Geoff,

Sorry to hear of the problems and you do seem to have checked the obvious causes.

A few comments and ideas:

The TPS voltage is a bit high - it should be between 27v to .47v and the throttle position will be about 10 -12%.

The fuel pressure should be 58psi but 54 is probably close enough and maybe down to the gauge. Do check it stays at full pressure whilst the engine is running as there have been a few instances where the fuel pump pressure drops off once the engine starts.

Have you checked the spark plugs? Take them out after running the engine for 10 mins or so. The electrodes should be a mid grey and if the are black that indicated a rich mixture, if white too lean. Check the plug leads and the coil packs - wipe them over with WD40 or similar and feel for cracks.

Check the intake system - are the throttle body mounting bolts tight and are all the hoses OK. Similarly check the exhaust header bolts are tight and the exhaust is not blowing slightly.

Another suspect could be the crank position sensor. Bunny or Planenut should be able to give more advice on this.

A final thought, did this start after filling up as it might be something as simple as bad fuel.

I think I will change the fuel pump and filter anyway. What is the best way to get the fuel out of the tanks?
Thanks

If your TPS is faulty, you may get P0122 or P0123, as they are related to that. They sometimes cause rough running when the wiper is worn or dirty but there is no easy way of fixing it other than replacement. There are no fault codes related to the Crank Position Sensor, there are some ways of testing them on You Tube.

Having the two cylinder adaptive map maxed out codes P0170 and P0173, usually indicates that the fuel supply is not being maintained at a steady 58psi. The pulse extends to try and give the correct closed loop fuel ratio and reaches its limit before getting enough fuel. Either the pump or the pressure regulator/filter could be the problem. If you still have the original fuel pump, rather than a replacement Walbro item, I would start with replacing the pump. The original pumps don't last long usually. Full detailed instructions on this forum at the top of the list under "Owners Resources"

Probably not a bad idea.

I can't remember if the new pump Roger put in at the Albert Ball was a Walbro or standard and the fuel filter's probably still the original one so will have seen better days.

No need to drain the tanks for either job. The fuel pump comes out the top of the tank and the petrol lines to and from the filter won't be under pressure and can be quickly blocked off when you detach them.

Thanks.
I have the fuel pump housing with the Walbro pump in it and a new filter, so will start with those.
At the least they will be new!
As the environmental joke goes: “ if climate change is a hoax, then we have saved the planet for nothing”
Cheers

The fuel pump I put in was a standard item, before we knew of Walbro

I have noticed a slight rattle on the last few drives of my 2017 model. Seems to settle after warmup.... let me know if you have any progress on this particular issue.
Regards,
Paul