Slight misfire on 1.9tdi AWX audi a4

**debjohn** · 24-11-2009,06:08 PM

sorry forgot to mention the new harness is easy flexible enough it does bend easy

**Alan02** · 24-11-2009,09:52 PM

Hi again,just reading through your last post,and also again at your first post......Forgive me for asking,but did you check that ALL Pistons where coming to TDC.Reason for asking is when the Tappet exploded i wondered what,if any damage was done to that Valve? Any contact with Piston?
It doesn`t take much to lower the compression Ratio for it to cause a misfire/White(unburnt) fuel.Have you had a compression Test?Can do it thru Glow Plug Hole.

**Buzzoff** · 25-11-2009,08:21 AM

Hello,

When we took the head off we inspected the pistons for any witness marks of any sort of contact and we did not see any, the piston bores were all good with no marks at all. We did manage to salvage all of the broken lifter.

When turning the engine over on the carnk my friend said that the engine felt like it was holding good compression (but I have not had a compression test done on it yet).

I know it seems like a long shot but the glow plug harness connector on cylinder 2 had split showing the wire, a couple of months ago I did find this and taped it up, drove the car to work and it seemed to cure the hesitation/misfire however on my return journey from work (35miles) it seemed to come back. Now I'm not sure if that is coincidence but the electrical tape did go soft and possibly stopped holding as well, I know it’s a long shot but what I’m also going to try is remove the insulation tape from the glow plug connector and replace it with a heat shrink.

What do you guys think?

Cheers,

Dan

**Buzzoff** · 25-11-2009,08:38 AM

Oh I forgot to say that the company who supplied and built the head for me did inform me that 4 valves were bent (I think that they were exhaust valves) They only told me when I collected it (even though I did ask to be informed if there were any issues when they first stripped my original head). Their explination was that there could have been a timing issue or the belt could have jumped a tooth or two.............

Even though we did not see any marks on the pistons

The company I purchased the replacment head from have been very unhelpful with my issue, in my opinion if a customer has spent nearly £900 with them I would expect a bit more help than they have given me. On my original invoice from them they have only guaranteed the head, cam and followers there seems to be no mention of their workmanship

Cheers,

Dan

**Alan02** · 25-11-2009,02:27 PM

Hi Dan,you can only say for certain with a compression tester.As for the glow plugs,you can try it,but couldnt say on the outcome.

**Buzzoff** · 30-11-2009,04:23 PM

Hello chaps,

I spoke to a ex vag tecnician today who runs his own business, before I went in to great detail of my issue he seemed to think that he would be able to diagnose the issue by running live on each injector.

He seems to think it will be down to a injector.

After being an ex vag technician for many year he was not surprised to hear how my local audi dealer had treated me.

Anyway I've got my car booked in with him to do the proper live scan and see what is what.

I'll keep you all posted

Cheers,

Dan

**Buzzoff** · 03-12-2009,04:26 PM

Hello chaps,

I met up with the ex vag technician today who put my car on his "snap on" diadnostics.
He did not find anything wrong with the injectors(no electrical issues) however he did find that my timing was out. He said it should be 60 degrees but it was infact 63.5degrees (he itold me that if the timing was out by a tooth it would equate to 6 degrees).
He is thinking that it could be caused buy the injectors not being correctly adjusted.
I informed him that I set them by backing them off by 180 degrees, however he is going to double check and see if they should be set at 225 degrees.
I will call him later to see what he has found.
Fair play to him because he did not charge me for his time

I'll keep you guys posted on what happens next.

Cheers,

Dan

**Buzzoff** · 07-12-2009,09:50 PM

Hello people,

I had a call back from the ex vag mechanic who informed me that after discussing my problem with his vag master tech friend that the injectors will need to be reset again. He has been advised by the master tech to set them by fully tightening the injector in all the way and then not backing it off (seeing that I set them by backing them off 180 degrees).

The master tech has advised this method in the past to other mechanics who have had cars with my problem and that it has cured this annoying misfire.

What do you guys think?
Could this do any harm?

The mechanic seems happy to do this as after all his master tech friend has used this method in the past.

To be honest with you I don't think a vag master technician would give out duff advice , I'm just wondering if anybody else has ever set up pd injectors like this(tightening in the injector grub screw and not backing it off by 180 or 225 degree)?

My only other question is how could my timing be out by 3.5degrees (seeing if it were out by a tooth it would be out by 6degrees)?

Keep the replys flowing,

Cheers

Dan

**Alan02** · 09-12-2009,02:01 PM

I can only say VW technical data advises to back-off the adjustment on the injector when its at full stroke,for obvious reasons of it bottoming-out on max.stroke.

**mark.abersoch** · 09-12-2009,07:16 PM

Originally Posted by Buzzoff

My only other question is how could my timing be out by 3.5degrees (seeing if it were out by a tooth it would be out by 6degrees)?

When i did my timing belt you could adjust the top sprocket (on the head). Maybe this could give some adjustment to remove the 3.5 degrees.

Hopefully that makes abit of sence to you. (it was on the AVF engine tho but would imaginr it would be the similar).