Needle valve sensor

[Mothy69]

I've got a misfire on idle & fault code 00542 comes up. It seems fine as soon as you use the throttle (maybe I can't hear it).

Ive got a quote for fitting a new fuel pump. Firstly has anyone a recommendation for supplying second hand or reconditioned ones (even part number)

Secondly could there be something else (cheaper!) That is causing the misfire & fault code?

Thanks for any advice

 

[Mothy69]

Anyone?

 

[sumo]

No2 injector has the needle valve sensor in so not sure about the pump ? Are we v6 tdi? If you tap the top nut on the no 2 injector with a 17mm spanner on idle does the idle change up or down?

 

[Mothy69]

Thanks.that's far too technical for me. I'm booked into the garage..

 

[Mothy69]

V6 tdi. So having been told its likely fuel pump, I've taken it to achieve garage who have replaced needle valve (in injector as said above). Part was 300 +VAT & 2 hours labour.

So I'm fixed & happy & cheaper than fuel pump..

 

[adamss24]

V6 tdi. So having been told its likely fuel pump, I've taken it to achieve garage who have replaced needle valve (in injector as said above). Part was 300 +VAT & 2 hours labour.

So I'm fixed & happy & cheaper than fuel pump..

They done you on labour, it takes less than 30 min to a skilled mechanic to change the needle lift sensor... glad it's fixed though...

 

[Mothy69]

Sadly this is not fixed. Needle valve sensor is, but misfire isn't.

Is there an easy way (not for me but a mechanic) to work out which injector is playing up to get it fixed rather them all reconditioned?

Would this show up on vcds for example? Or is it a case of removing & testing each?

 

[frankc]

VCDS measuring blocks 13 & 14 for injection quantity deviation...

You'll notice injector 2 isn't shown as it is used as the baseline and the values given are when compared to it.

In my picture above injector 5 is showing the greatest deviation. My car has a very noticeable misfire/vibration under load which I traced to one of the injectors which had a deviation of about -2.3.

Frank

 

[Mothy69]

This is great info. Thank you. As I've had a new no. 2 injector! This should be a good baseline to show which aren't working properly.

Off to vcds map for help.. thanks again

 

[adamss24]

This is great info. Thank you. As I've had a new no. 2 injector! This should be a good baseline to show which aren't working properly.

Off to vcds map for help.. thanks again

Usually misfires on the v6 tdi engines are due to wear on the cams and fallen lifters however it should have been picked up by the garage that changed the 3rd injector if they worth their salt ! I would say to take the rocker cover again and check the cams and lifters for wear...

 

[Mothy69]

Usually misfires on the v6 tdi engines are due to wear on the cams and fallen lifters however it should have been picked up by the garage that changed the 3rd injector if they worth their salt ! I would say to take the rocker cover again and check the cams and lifters for wear...

Worn cams sounds quite terminal £ wise. Can you enlighten me further?

 

[adamss24]

Where abouts in the country are you based ? I have a few good cams in my workshop, with a new set of rocker arms and lifters the engine will be like new ! If you don't mind driving down to London one weekend then pop in and leave it with me for the day !

 

[Mothy69]

Where abouts in the country are you based ? I have a few good cams in my workshop, with a new set of rocker arms and lifters the engine will be like new ! If you don't mind driving down to London one weekend then pop in and leave it with me for the day !

I'm south east (Brighton) but regular in London. I'm going down the injector testing route as that's cheap to do & see what happens there - if not I'll pm you & talk further.

Thanks for help & advice - wish me luck!

 

[adamss24]

If you want to save money best come and see me !

 

[Mothy69]

Waking up in the night thinking about your car is never good - I think I'll be in touch shortly..

 

[Mothy69]

So here goes...............

having had it running lumpy (i thought misfire) on idle for a while now (but runs smooth as once under way) I have been trying to get to the bottom of it. Here is what I have found. I sent it into a diesel diagnostics, pump & injection centre (who are well recommended near me), & they have said:

Tested all injectors & they are fine (disappointing as cheap to fix)
Compression test on engine & all cylinders are fine
Visible inspection of cams & minor wear but not anyhing you wouldn't expect & that shouldn't cause an issue (2nd garage to have said that)

They have said they think its likely to do with a worn dual mass flywheel causing vibration when its idling & that disappears once its moving faster. They reckon they have seen this in other vehicles where diagnostics shows nothing wrong with the injection and engine & is that. Penny for your thoughts & opinions as to whether this could be the issue?

I would quite like it to be - as new clutch & flywheel = an area that i know is weak on the car - a bit of a gritty pull away (I've been thinking its going) & high clutch pedal, also recently a couple of snatched gear changes coming down to 3rd.. this could also tally with a previous problem, where it wouldn't go into gear & i had to call out RAC - RAC said clutch, Mr Clutch said gearbox - but having drained oil & replaced it went into gear & ran fine again (apart from lumpy idle). I've been running it for probably 4 months since.

So. any opinions before i go all in for a new clutch & dual mass? (£995 with Mr Clutch)