R36 loss power- misfiring

[bigdaddy786]

HI everyone,
I've not long bought a R36 and having a few major issues with it, noticed the power going down and now its starting to misfire, Ive changed the plugs twice with new coils but still no luck. Vw just fobbing me off as there no fault codes.

Any suggestion ladies and gents?

Ive checked vcd block 208/209 - intake is -3 and exhaust is 2 kw

Ive done vcd logs as you can see below

How do i log fuel pressure / injectors ? Any thing else perhaps

[bigdaddy786]

	'002				'020				'021
	Engine Speed	Engine Load	Injection Timing	Mass Air Flow	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation
	(G2			(G70)	Cylinder 1	Cylinder 2	Cylinder 3	Cylinder 4	Cylinder 5	Cylinder 6
Marker	/min	%	ms	g/s	°KW	°KW	°KW	°KW	°KW	°KW
	1720	50.4	3.06	40.81	0	0	0	0	0	-3
	2240	76.7	4.34	68.56	0	0	0	0	0	0
	2920	85.7	4.34	96.36	-3	-6.8	-6	0	0	-0.8
	3600	81.2	3.83	113.78	-3	-6.8	-6	0	-2.3	-2.3
	4440	81.2	4.34	138.58	-1.5	-9	-7.5	-6.8	-2.3	-2.3
	5240	80.5	4.59	164.69	-0.8	-9	-7.5	-9	-2.3	-1.5
	5920	82	4.59	188.64	-0.8	-9	-6.8	-9	-3.8	-1.5
	6440	81.2	4.59	204.19	-0.8	-9	-6.8	-9	-3.8	-1.5
	4720	85.7	4.84	154.86	-3.8	-8.3	-6.8	-9	-3.8	-1.5
	5160	82.7	4.59	166.39	-3.8	-8.3	-6.8	-10.5	-3.8	-4.5
	5520	85	4.84	183.61	-3.8	-9	-6.8	-10.5	-3.8	-4.5
	5920	83.5	4.84	191.86	-3.8	-9	-6.8	-10.5	-3.8	-4.5
	6280	82	4.59	200.64	-3.8	-9	-6.8	-10.5	-6.8	-4.5
	6560	81.2	4.59	207.69	-3.8	-8.3	-6	-10.5	-6.8	-4.5
	5520	86.5	3.57	188.78	-3.8	-9	-6	-10.5	-6	-4.5
	5080	85	4.84	168.17	-3.8	-8.3	-6	-10.5	-6	-4.5
	5320	84.2	4.84	175.42	-3	-8.3	-6	-9.8	-6	-3.8
	5480	85.7	4.59	182.86	-3	-8.3	-6	-9.8	-6	-3.8
	5440	13.5	1.28	26.03	0	0	0	0	0	0

[bigdaddy786]

	'002				'020				'021
	Engine Speed	Engine Load	Injection Timing	Mass Air Flow	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation
	(G2			(G70)	Cylinder 1	Cylinder 2	Cylinder 3	Cylinder 4	Cylinder 5	Cylinder 6
Marker	/min	%	ms	g/s	°KW	°KW	°KW	°KW	°KW	°KW
	1720	50.4	3.06	40.81	0	0	0	0	0	-3
	2240	76.7	4.34	68.56	0	0	0	0	0	0
	2920	85.7	4.34	96.36	-3	-6.8	-6	0	0	-0.8
	3600	81.2	3.83	113.78	-3	-6.8	-6	0	-2.3	-2.3
	4440	81.2	4.34	138.58	-1.5	-9	-7.5	-6.8	-2.3	-2.3
	5240	80.5	4.59	164.69	-0.8	-9	-7.5	-9	-2.3	-1.5
	5920	82	4.59	188.64	-0.8	-9	-6.8	-9	-3.8	-1.5
	6440	81.2	4.59	204.19	-0.8	-9	-6.8	-9	-3.8	-1.5
	4720	85.7	4.84	154.86	-3.8	-8.3	-6.8	-9	-3.8	-1.5
	5160	82.7	4.59	166.39	-3.8	-8.3	-6.8	-10.5	-3.8	-4.5
	5520	85	4.84	183.61	-3.8	-9	-6.8	-10.5	-3.8	-4.5
	5920	83.5	4.84	191.86	-3.8	-9	-6.8	-10.5	-3.8	-4.5
	6280	82	4.59	200.64	-3.8	-9	-6.8	-10.5	-6.8	-4.5
	6560	81.2	4.59	207.69	-3.8	-8.3	-6	-10.5	-6.8	-4.5
	5520	86.5	3.57	188.78	-3.8	-9	-6	-10.5	-6	-4.5
	5080	85	4.84	168.17	-3.8	-8.3	-6	-10.5	-6	-4.5
	5320	84.2	4.84	175.42	-3	-8.3	-6	-9.8	-6	-3.8
	5480	85.7	4.59	182.86	-3	-8.3	-6	-9.8	-6	-3.8
	5440	13.5	1.28	26.03	0	0	0	0	0	0

[bigdaddy786]

Group A:	'014				'015				Group C:	'016
	Engine Speed	Engine Load	Misfire	Misfire	Misfire Counter	Misfire Counter	Misfire Counter	Misfire		Misfire Counter	Misfire Counter	Misfire Counter	Misfire
TIME	(G2		(total)	Recognition	Cylinder 1	Cylinder 2	Cylinder 3	Recognition	TIME	Cylinder 4	Cylinder 5	Cylinder 6	Recognition
STAMP	/min	%							STAMP
104.13	1520	33.1	0	Enabled	0	0	0	Enabled	104.4	0	0	0	Enabled
104.52	1520	27.1	1	Enabled	0	1	0	Enabled	104.77	0	0	0	Enabled
104.9	1520	24.8	1	Enabled	0	1	0	Enabled	105.15	0	1	0	Enabled
105.27	1560	25.6	2	Enabled	0	1	0	Enabled	105.52	0	1	0	Enabled
105.64	1560	27.8	2	Enabled	0	2	0	Enabled	105.9	0	1	0	Enabled
106.02	1600	33.8	4	Enabled	0	3	0	Enabled	106.27	0	1	0	Enabled
106.39	1640	33.8	4	Enabled	0	3	0	Enabled	106.65	0	1	0	Enabled
106.77	1680	32.3	4	Enabled	0	3	0	Enabled	107.02	0	1	0	Enabled
107.14	1720	28.6	5	Enabled	0	5	0	Enabled	107.39	0	1	0	Enabled
107.52	1760	27.1	6	Enabled	0	5	0	Enabled	107.77	0	1	0	Enabled
107.9	1520	33.8	6	Enabled	0	5	0	Enabled	108.14	0	1	0	Enabled
108.28	1400	39.8	6	Enabled	0	5	0	Enabled	108.54	0	1	0	Enabled
108.66	1360	40.6	6	Enabled	0	5	0	Enabled	108.91	0	1	0	Enabled
109.03	1400	39.1	6	Enabled	0	5	0	Enabled	109.28	0	1	0	Enabled

[bigdaddy786]

'002				'020				'021
Engine Speed	Engine Load	Injection Timing	Mass Air Flow	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation
(G2			(G70)	Cylinder 1	Cylinder 2	Cylinder 3	Cylinder 4	Cylinder 5	Cylinder 6
/min	%	ms	g/s	°KW	°KW	°KW	°KW	°KW	°KW
1720	50.4	3.06	40.81	0	0	0	0	0	-3
2240	76.7	4.34	68.56	0	0	0	0	0	0
2920	85.7	4.34	96.36	-3	-6.8	-6	0	0	-0.8
3600	81.2	3.83	113.78	-3	-6.8	-6	0	-2.3	-2.3
4440	81.2	4.34	138.58	-1.5	-9	-7.5	-6.8	-2.3	-2.3
5240	80.5	4.59	164.69	-0.8	-9	-7.5	-9	-2.3	-1.5
5920	82	4.59	188.64	-0.8	-9	-6.8	-9	-3.8	-1.5
6440	81.2	4.59	204.19	-0.8	-9	-6.8	-9	-3.8	-1.5
4720	85.7	4.84	154.86	-3.8	-8.3	-6.8	-9	-3.8	-1.5
5160	82.7	4.59	166.39	-3.8	-8.3	-6.8	-10.5	-3.8	-4.5
5520	85	4.84	183.61	-3.8	-9	-6.8	-10.5	-3.8	-4.5
5920	83.5	4.84	191.86	-3.8	-9	-6.8	-10.5	-3.8	-4.5
6280	82	4.59	200.64	-3.8	-9	-6.8	-10.5	-6.8	-4.5
6560	81.2	4.59	207.69	-3.8	-8.3	-6	-10.5	-6.8	-4.5
5520	86.5	3.57	188.78	-3.8	-9	-6	-10.5	-6	-4.5
5080	85	4.84	168.17	-3.8	-8.3	-6	-10.5	-6	-4.5

[Lucas_R]

I would start with the absolute basics. Seeing that you have already changed spark plugs and ignition coils then I would do the following:

- Check and clean the MAF sensor between the airbox and the throttle body (even check the MAF sensor is facing the correct way).
- Check and clean the throttle body.
- Check for air leaks on the intake (perished rubber lines/clamps not done up tightly etc).
- Then I would start looking at fuel pressure issues. Im not sure if the R36 has a replaceable fuel filter, but if it does - replace it. Then look at the low pressure fuel pump in the fuel tank, or the high pressure fuel pump on the engine.

[bigdaddy786]

I would start with the absolute basics. Seeing that you have already changed spark plugs and ignition coils then I would do the following:

- Check and clean the MAF sensor between the airbox and the throttle body (even check the MAF sensor is facing the correct way).
- Check and clean the throttle body.
- Check for air leaks on the intake (perished rubber lines/clamps not done up tightly etc).
- Then I would start looking at fuel pressure issues. Im not sure if the R36 has a replaceable fuel filter, but if it does - replace it. Then look at the low pressure fuel pump in the fuel tank, or the high pressure fuel pump on the engine.

How would you suggest cleaning the maf? its the right way don't think it goes another way as it screws to airbox.

cleaned the tb and done alignment

cant see any air leaks, but brake pedal has a slight hiss but goes away.

There no service fuel filter, just one the fuelpump in the tank ive read.
anyway to check fuel pumps pressures eg via vcds ?

[Lucas_R]

How would you suggest cleaning the maf? its the right way don't think it goes another way as it screws to airbox.

cleaned the tb and done alignment

cant see any air leaks, but brake pedal has a slight hiss but goes away.

There no service fuel filter, just one the fuelpump in the tank ive read.
anyway to check fuel pumps pressures eg via vcds ?

There are cleaning sprays for the MAF sensor. Good to hear its facing the correct way - with some cars it can only fit one way to prevent people putting it in the wrong way.

You literally just spray the MAF sensor (and any of the hot wires which may/may not be visible) and the cleaner just makes them spotless and the liquid evaporates within a few seconds. I was helping my neighbour diagnose a rough idle and misfire on their car just yesterday and cleaned the MAF as part of my work (MAF was filthy as well as the throttle body and idle control valve - i suspect its never been cleaned in 20 yrs).

As for fuel pressure logging, im not sure if the R36 can do this with VCDS. You would just have to have a poke around and experiment.

Also, another thing to add to your list of possible culprits is the PCV valve. The PCV is very common to fail on the R32 and R36 engine and can cause misfires as it allows air to enter the engine that has not been registered by the MAF sensor. This place sell a kit with new internal parts: RKX VW & Audi 3.6 & 3.2 Engine Valve Cover PCV Valve Diaphragm – RKXtech

Another thread with similar issues to you: Passat R36 Idling Rough

[MMR36]

On top of the suggestions today, the R36 has low and high fuel pressure sensors, the sensors should throw a code if they fail or sense incorrect pressures, VCDS can read fuel pressures, check Live Data in the engine control unit.

The filters in the fuel pump (in the right side tank under the rear seat) are supposed to be life time (brilliant) and a cleaner additive is specified at service intervals to clean them out. Modern fuels should also help with that. There are a few you tube vids in your part of the world of filters being replaced in the pump. They are very expensive lumps of mostly plastic to replace the whole thing.

The left side tank has a slave 'pump' that the main pump uses to draw fuel out of the left tank into the pump as the tanks are joined in a saddle arrangement. The slave maybe dirty if tanks have been had some poor fuel. I had to crack open both sides of my at the 10 year mark (chasing a fuel pressure issue) and they were pleasingly spotless both sides, the main pump filters were, well, ten years of filtering was evident.

[meeso]

Interesting.. Mine did similar, but i also had the timing chain chatter on startup for a period perceding, which i ignored after reading it was common, Ended up being undrivable, and the engine had disintegrated the timing chain guides, and the trailing side of the chain (opposite the tensioner side) on the top chain, was flapping, and jumped teeth on the fuel pump drive pulley. symptoms were horrid screetching as well.

[bigdaddy786]

Guess brake cleaner would be no good at cleaning it?
did cleaning the maf on your neighbours car make much difference?

Think can log fuel bar pressure to see whats its running, just some of the blocks have no labels on em makes harder to judge what its for

Was trying to avoid that pvc due to cost of new rocker cover. but didnt knew you cant just get new valve and easy to swop over. I'll order one. Thanks for that

[bigdaddy786]

I have no codes so far, which makes things difficult more. do you know which blocks to log see what pressures are?

so filter on the main pump in the tank did you replace it?

[bigdaddy786]

Oh god , that looks terrible, did you have any engine damage beside the timing chain/guides?

[Umai Naa!!]

Post up the misfire counters for each cylinder.

If it's noticably high on one cylinder, I'd be inclined to think it's a dead injector, since you've already done plugs and coils.

Also check the tiny bypass hole in the valve cover, near the breather pipe. Hard to spot, but it's there. If its hissing air out of it while the car is running, it'll need a new PCV diapragm.

[bigdaddy786]

This log was done driving, but it misfire on idle sometimes or if you blip the throttle.
Maybe getting the injectors cleaned/flown tested, i need t keep cost down as i cant afford guessing faulty parts.
Oh great i'll have a check for that hole, finger crossed, but can a faulty pvc valve cause so much issues?