Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Complex EFi issue

Either. Will stall at the end of my drive from stone cold, joining the main road a mile away or at the traffic lights in the next town 6 miles away. Or it won’t stall at all.

Resistor didn’t turn up so no playtime today.

Gary.

Hi Gary, no resistor may be a good thing!
It is known that the information you get from the ECU may not be correct. The ECU only manages the fuel and knows nothing about the electrical side of internal combustion. If a problem occurs on the electrical side it may report no error code or it may have a guess but only has 'fuel language'. It is up to us to interpret the information.
I had intermittent stalling/cutting out and the ECU reported error code 21, a tune resistor problem. I discussed this with someone who had extensive Rover V8 experience. He advised me to look elsewhere for a solution.
You can make some electrical measurements using a multimeter which can indicate which component is at fault. This pointed to the ignition amplifier on the side of the coil. Replacing that solved my problem.
I would hesitate before altering the wiring loom.

As I have already admitted, I have zero experience of fault finding on ECU controlled fuelling systems..

I wonder if you have an air leak allowing for a weak mixture at tick over that has little to ne effect at highr revs... Yeah clutching at straws. I have used a length of tube held to my ear and moved the other end around the inlet manifolding and vaccuum connections for dizzy and servo etc... I have read of others spraying easy start with the engine running to detect such leaks but that seems to have potential to create problems..?

Good luck.

finally got a chance to play today and I have made a difference..




before today the gear selected was drive/park and now its categorically manual

base idle was off at 600 as previous set, now at 525 with bypass airway blocked. Idles nicely at 750rpm connected.

lambda readings have changed markedly too

So I've made a change but if the stalling has stopped only time will tell. Need to get a few miles under the belt now I think. Next week......

Wizzard.

Oh, timing was bang on at 8 degrees (actual) BTDC.

And for good measure I've ordered a local ignition amplifier just in case

Have you checked/changed the ignition amplifier? When these start to break down they become very sensitive to temperature. So driving along with a nice air flow ,it will be fine, when you stop the under bonnet temperature will increase causing the amplifier to do things it should'nt and the longer you are stopped the hotter it becomes -the worse its behaviour is
Cheers

As above. New one arriving today.

Oh and it will cut out irrespective of temperature. Sometime just getting off the drive or at the end of my street. Sometimes after a 30 mile none-stop run. Sometimes not at all for weeks, sometimes every stop. There’s no pattern unfortunately.

well I've discovered even more wizzardy stuff. Inside the MAF is a multi turn trim pot, this allow the voltage across the hot wire to be calibrated for cats/no cats.



Oh and yes I've fitted a new Lucas Ignition amplifier (but its probably junk Lucas)

touching wood everything has been fine since I installed the resistor mentioned above.

It is not normally necessary to take the top off the MAF, just read the voltage range as you have done and adjust using the adjusting screw, make sure the top is sealed when you refit any moisture getting in there and it is toast. Whilst you were playing with the MAF did you clean the wire, always a good idea regular electrical contact and tuner cleaner works?