Just changed the timing belt on my 2008 TD4. 180,000miles so it was probably living on borrowed time.

Used all the correct procedures – locking pins, flywheel lock etc. Belt change went smoothly. Did all the ‘turn the engine over ten times to set the tensioner’ etc. No problems.

Now that I come to start the car, it won’t start. It will turn over and fire, but then dies and then won’t fire again until the key is withdrawn and inserted again.

My way of thinking says that to fire up, there must be compression, fuel and air – so I haven’t bent a valve changing the timing belt (and I don’t see how I could if it was all lined up and couldn’t move while it was being changed).

I know my throttle valve is worn out and there were throttle valve fault codes but I have taken this off and the valve is fully open, so it isn’t being starved of air due to a stuck closed flap.

I can only think that the fuel supply is being cut by the ECU. But why? I have looked round and can’t see any loose wires to any sensors and as I have said, the only fault codes showing are ones to do with the throttle body.

Any ideas anybody?

The only thing I can think of is the crankshaft revolution sensor may not be connected properly.
It is the only thing disturbed during belt change that may cause a problem.

Obviously if the belt is a tooth out it will cause starting and running problems.

Hopefully something simple and easy fix

Joe Fix it until it's broke !

I should have said - the rev counter is working when it fires up so it shouldn't be the crank sensor.

Is this an interference engine do you know? Could it still run with the belt one tooth out?

Yes, it is possible that it would still fire,run roughly and cut out, if you incorrectly fitted the belt.
I would double check, repeat the complete timing procedure.
It seems a coincidence this has happened after you completed this task.

Joe Fix it until it's broke !

Thanks for the reply - thats exactly what I've been doing while you were replying and guess what?
It was one notch out.

I guess that I didn't have the tension right on the right hand side of the belt before I tensioned it up and that turned the pulleys slightly.

I'm just amazed that it turned over so easily and fired up with the belt in the wrong position. I guess I've been lucky but you live and learn.

Quote:

Used all the correct procedures – locking pins, flywheel lock etc. Belt change went smoothly.

Quote:

I guess that I didn't have the tension right on the right hand side of the belt before I tensioned it up and that turned the pulleys slightly.

The crank gear is designed to move a few degrees on the shaft when tensioning, to ensure all the slack is out the belt

Still doesn't explain why it was that far out though