MGZT diesel with sudden starting troubles.

[COLVERT]

Originally Posted by grivas

What you have read there is 'residual' voltage, which is misleading, leave it to stand for an hour and you will find the battery is dead.
CHARGE the battery for 24 hours, then leave it disconnected for 1 hour then measure voltage, it should read at least 12.5V, start car and check voltage with engine running, should be 14.4V +, switch lights on, radio, demister and check again, should be near 13.8v any significantly lower readings, need a new battery, and your alternator is probably in need of attention, new regulator pack?. Good luck.

You misunderstood the post you are replying to.--Also

You can't check a battery voltage with the engine running.------just the charge rate.

[Gizmo150]

Originally Posted by COLVERT

You misunderstood the post you are replying to.--Also

You can't check a battery voltage with the engine running.------just the charge rate.

I wasn't checking the battery with the engine running, that was the voltage supplied by the alternator. I thought we established that in you early post. The battery disconnected is reading 12.3v after charging. So I'll replace it to eliminate that.

This morning I got it started after cranking the engine twice for 10 seconds but it was rough ticking over like a small petrol engine when it's 'hunting' for fuel. It cut out after 4 miles at a junction and took a time to restart. I had the battery replaced at a Garage. The engine died twice on the way home with the usual starting problems. So I now have a new battery and the same starting problem.

[Arctic]

You need to do an injector leak back test, sounds like an injector, plenums maybe clean but as the ECU got wet before ?

[Gizmo150]

Originally Posted by Arctic

You need to do an injector leak back test, sounds like an injector, plenums maybe clean but as the ECU got wet before ?

I took the ECU out. No water marks on the outside. Took out the screws. Unit is clean inside with no signs of water or damage. Warmed it in the wiring cupboard over night. Cleaned contacts and put unit back in place. No change to starting problem.

Took engine cover off and started looking at all the wiring connectors. Found a defective wire in the fuel rail connector. Repaired and engine fired immediately.

So a big thanks to the brain trust here. An invaluable resource. So pleased my Le Man's Green machine is going again. Love this car, it's been 16 years of reliability and only left me stranded once with a dead alternator until recently.