Random Injection Quantities

[GarJE]

I've been trying to pin-down the cause of my lumpy BKD idle (which a lot of others also have). I've run a scan and all that seems obvious is this:

Address 01: Engine (03G 906 016 ET)
10:39:59 Group 013: Idle Stabilization (Injection Quantity Deviation)
-0.09 mg/str Injection Quantity Deviation Cyl. 1
-0.26 mg/str Injection Quantity Deviation Cyl. 2
-0.66 mg/str Injection Quantity Deviation Cyl. 3
1.06 mg/str Injection Quantity Deviation Cyl. 4
Tuesday,23,December,2008,10:41:26:19611
VCDS Version: Release 805.1
Data version: 20080823

Anyway. Does this seem odd? The others are around similar values, but Cyl. 4 is way out of sync.

[Crasher]

A long way out but well within spec. Is it an early BKD in an A3, does it use water and are there any codes such as glow plug 1. Try changing the in head harness, I have done a few and it has cured the poor idle in some but not all.

[Crasher]

Sorry, I can see it is a Golf 5 from the ECU number.

[GarJE]

A long way out but well within spec. Is it an early BKD in an A3, does it use water and are there any codes such as glow plug 1. Try changing the in head harness, I have done a few and it has cured the poor idle in some but not all.

You're right! It is a Golf. One of the first I believe ('53).

Funny you should mention the above, as it was loosing quite a lot of coolant until I got the rad repaired a few months ago (still looses a tiny amount even now).

Although, there's no fault codes thrown at all when scanned. I had heard about the harness. What happens to it and is it a difficult job (will do it myself).

Cheers for the help so far. You're a star!

[Crasher]

They are quite a lot more work than the 8v PD engine but not too difficult to do. There is a known issue with the BKD where they develop a porous head casting, usually on number one plug. I have often seen this cause a glow plug fault code on the faulty cylinder. The only cure is a new head. I suggest you do the glow plugs whilst you are in there, saves going in twice

[GarJE]

Cheers crasher!

How much would a new harness/glow plugs be?

Would I definately get a glow plug fault if I had the porous head issue? Plus, would there be any other symptoms (e.g oily coolant)?

I think the leak is from the "repaired" rad. Should have just bought a new one while I was at it .

Gareth.

[GarJE]

The latest in the saga:

Decided that I wasn't going to change anything until I had some definitive proof of something wrong, so decided to get my hands dirty.

Pulled the Valve cover off and checked the camshaft lobes for wear, which were perfect. So no problems there.

Next, decided to check for any clearence between rocker and injector. No clearance on any. So no problems there.

Next, decided to check resistances on the injector loom (this is where the problem may lie).

Cylinder 1:

Grey = 0.3 Ohm
Brown (com) = 0.3


Cylinder 2:

Red = 0.3
Brown (com) = 0.3


Cylinder 3:

Yellow = 0.2
Brown = 0.3


Cylinder 4:

White = 0.6
Brown = 0.3


So, in the cable which should be the lowest resistance (as it's the shortest), the resistance is the highest (double of all the others) which just happens to be the cylinder which is showing this out-of-sync injector reading.

Do you think this is barking up the wrong tree, or is there something in this? In which case the logical step will be to replace the injector loom.

[Crasher]

The harness is about £67 and part number 03G 971 033 D. I have seen A3’s show a glow plug error cylinder 1 when they have been leaking into cylinder 1, change the harness.

Repaired radiators are a mugs game.

[Theresias]

Since you didn't post a real scan, make sure the ECU has at least SW 03G-906-016-ET @ 7215.

[Crasher]

He means check the software level is at least up to version 7215 in the main engine screen.