Hello, I hope the following is of assistance.
To start with I would recommend checking the amount of power drained by the starter motor, if the battery voltage drops below around 10.5 volts this can cause the engine management to shut down giving the non start condition, when you release the key the starter stops taking power and the engine management operates again. The reason the engine starts with a tow is that as the starter motor isn't operating the battery voltage remains high enough that the engine management doesn't shut down. When you start the engine on "easy start" the engine management shuts down but the engine runs on easy start, once you release the key after the engine has fired the battery voltage is enough that the engine management operates so the engine will continue to run.
If it is the starter motor bringing the battery voltage down check that there aren't any metallic particles in the starter, this could indicate a flywheel fault which is common on this engine, also having this contamination means the starter requires more power to operate.
Start with checking the battery condition and voltage at cranking, if you have access to a diagnostic scanner connect this and check if it loses communication with the engine management when you crank the engine, this would confirm the starter is drawing too much power.
Let me know if I can assist further or if you have more questions regarding this and I'll reply as soon as I'm able to.
Thank you for a swift reply Sean, Your answer seems very logical. The only negative I can see with your answer is that I have tried to start the van via jumper cables from another vehicle. Would this not then ensure an adequate voltage to run the engine management unit while cranking the engine? This fault has appeared suddenly rather than over a period of time if that makes any difference. I will be rating whatever your answer is at the highest level to ensure you get the credit. I do appreciate your help.
Hello again Geoff,
usually trying jump leads doesn't make a difference when the starter is causing the problem, to be honest unless heavy duty jump leads are used they aren't capable of transferring the full power from a donor battery as this engine uses around over 300 amps just to turn the engine over.
With regard to the fault just appearing, this will have happened as soon as the starter was using too much power causing the battery voltage to drop and the engine management to shut down, obviously once this has happened it isn't going to improve unless the starter is replaced or overhauled.
As I mentioned earlier if you can check the battery voltage when cranking the engine, this will go some way towards confirming this is the problem.
Let me know if I can assist further.
Thanks Sean, I'll be checking the things you've suggested tomorrow. Hopefully problem will be resolved.
Thanks again for your recent help, however this one is a bit of a puzzler. Today I've been and bought a brand new heavy duty and fully charged battery. Fitted it and tried to start the van Still the same result . Turns over fine but will not fire up. It does still fire up with a squirt of easy start into the air intake. After which I left the van running for a full half hour and the turned the engine off and immediately tried to restart ... same result... turns over but wont fire. Any other clues would be appreciated. PS I hope you have received payment from yesterday
this all still comes back to the amount of power the starter motor is drawing, even with a good battery or a set of jump leads if the voltage drops quick enough you end up in the situation you have, fitting a new battery won't resolve a starter motor concern, as I mentioned previously you need to check the actual voltage when trying to start the engine.