Not sure what it might be - no fault codes logged. Sometimes my car takes a good 4 seconds+ of cranking over before it fires into life. I'm putting it down to being something to do with the starter motor and/or the superlight flywheel that it turns to start it up. Wondering if there's an easy place to start looking? Only done this 2 or 3 times, and even since the flywheel was fitted, has never failed to start within half a second or so (i.e the usual)

I know it sounds stupid, but when my golf tdi did this turned out one of the glow plugs was only slightly glowing!!

no reason it's not the same thing now, but no glowplug faults come up. (yet )

Sounds like a good point.

But this will usually store a fault in the momory, or even bring on the light.

maybe it's something as simple as a knackered battery. Not enough juice is getting to the starter motor to turn the crank over.

Possibly the battery, but there's no other signs of poor voltage, and when the battery dies it usually doesn't crank over cleanly, and the dashpod display goes blank. This is cranking over cleanly, but not cutting in.

At least if it is a new battery, I can change one over in under a minute due to it being so easily accessible in the boot.

Glowplugs is my bet.

Well, I have a set to go in the new head, so perhaps this "issue" has come at a good time.

If you've got your big injectors in then thats the problem :P If not then glowplugs is my bet.

Injectors are still sealed in their bags they arrived in, but it won't be long.

Sounding more like glowplugs - the light has not been lit for any longer than usual when starting up. Tomorrow I might see what doing 2 glowplug lighting up sessions does.

Were the days it took longer to start any colder or had the car sat for any longer than usual?

Sometimes mine will do this. Even though the glow plug light goes out, the engine will not start. It doesn't take long to start normally so I dont let it crank over for long. I turn the ignition off and on again, wait for the light to go out and it will start then.

When I get the feeling it might do it, cold mornings for example, I do 3 cycles just to be sure it will start. And it always does.

Does the crankshaft position sensor take measurements off the flywheel?

Not too sure on the set up on modern engines, perhaps there is some slight difference between the new and old flywheels giving a change in clearance.

This would probably give an error code though, so it's probably not this.

When it does eventually fire up is there lots of smoke thrown out ?

If so probably glow plugs IMHO

Does the crankshaft position sensor take measurements off the flywheel?

Not too sure on the set up on modern engines, perhaps there is some slight difference between the new and old flywheels giving a change in clearance.

This would probably give an error code though, so it's probably not this.

The ECU is quite clever in this engine... being that the Engine has a Crank sensor AND a cam sensor, it uses both to determine what position the engine is in so can start quicker... if one of the sensor fails, it flags an error but can still work ok off one sensor

I've got a crankshaft position sensor intermittent/fault on mine (230k+ miles on the clock) - and that can and has caused a few non-starts, as well as mildly dodgy starts. However the glowplugs get my vote unless you've got errors logged

Im wondering now if my plugs are dodgy...as my car is a bugger to start all the time, worse when cold. I do have big injectors though....let me know how you get on with the new injectors Jase

When it does eventually fire up is there lots of smoke thrown out ?

If so probably glow plugs IMHO

Yeah - A fairly decent amount of white smoke. Plus quite lumpy for first 15 seconds or so.

Yeah - A fairly decent amount of white smoke. Plus quite lumpy for first 15 seconds or so.

From what I remember of couple of occasions (over a good few years) that would be glow plugs.

If you 'reheat' by turning ignition on and off a few times before turning key to kick in starter motor does this improve matters ?

Check you are getting the full voltage at the glow plugs ??.

Have had as similar problem with mine - just when it's warm - have to keep the starter running after it catches, it dips the rpms and then all is well.

Seems to be part of uprated injectors - you can lean out the start up conditions using veg-com, which helps, or mention this to your tuner to lean out the start-up conditions set by the ECU by the % bigger than OEM your injectors are.....

May be related to your uprated cam matey - dumping in more fuel than the car likes for start-up. Do try leaning out the start-up - see Ross-Tech: VAG-COM: TDI VAG-COM Info

channel 5 adaptation. Despite the disclaimer stating that this is not for PD engines - I was able to adjust my idle upwards to make the dogbone shudder go away using these instructions.....

HTH

Bas

Maybe its an air leak in your fuel system? Ive convinced myself thats what ive got after fitting an aftermarket fuel filter, i think that over time it lets a bit of air in the fuel pipes which then have to clear until my car starts. It takes about 3 seconds and a blip of the throttle to get mine started on cold mornings, if i dont blip the throttle my idle is terrible. I can live with it until i change my filter when i do my 70k service.

Thats not right.... mine starts on the key, every time!

Well, she did it again this morning - not as bad, but then it's a bit warmer so perhaps thats negating some of the effects of dodgy plugs. The new head will be going on soon so I'll just live with it until then - new plugs going in then anyway.