Well, it seems that I have managed to solve my erattic idle/misfire problems that have been getting worse over the last few weeks.

VAG-COM was logging misfires and you could hear them from the exhaust, one of the coil packs was of the old style and 2 were intermediate - so I changed all 4.

This made no difference, so I changed the plugs.

This made no difference so I thought I'd have a poke around.

Found a split vacuum hose at the front of the engine (you may remember I posted a photo). Eventually had the time to investigate further on Saturday and discovered the 6" hose had a 2" split down one side! I've used some aluminium tape as a temporary fix and ordered a new part from VW. Incidentally, the part has been superceeded so I hope it wont happen again.

Now this is fixed, combined with a clean air filter, new plugs, oil change and coil packs the car is running very well indeed - still got the random power loss issues that a few others have but generally it's like a different car to the one it was last week.

Still got a few issues/flat spots/timing issues with the remap but that will be sorted in a few weeks

Considering I was ready to ditch the Octavia in favour of a Golf GTi and some heafty HP payments I'm now a happy chap

The hose was under £10 and the coil packs and plugs about £130 - I diddnt need to change them but it saves me doing it again in the future. Luckily not had to shell out for a new MAF either.

Big thanks to Bengie, Quniten and Phil "piv34uk" for helping out along the way

Hmm gald you posted that! Sounds similar to my problem. The fault reader is detecting misfires on 1 and 4 (occasionally 2) and also has some funny readings from a few air sensors. The problem has to be pretty minor as I can't tell a difference. Its a 2.0L engine but I reckon it could be the same problem, I just changed the pluigs, leads and air filter at the weekend to no avail. You couldn't descibe where to find the split pipe could you? What diameter is it? Is it a rubber, platic or fabric covered pipe? its got to be worth a shot (the garage want to fit a new ECU! I bet they do at £800!)

Regards.

http://www.philgooch.com/octavia/hose1.jpg

and

http://www.philgooch.com/octavia/hose2.jpg

The hose that had split was the one that runs to the left of the red arrow in the second photo. It is very fiddly to get to but if you remove the main plastic engine cover, then the other smaller cover (if fitted) you can then get to a bracket on the front of the manifold (the dip-stick goes through a hole in the bracket, see first photo).

Remove 2 screws and 2 nuts that hold the bracket to gain some movement, you will see this hose connects to a fitting on the underside of the casting. At the other end of the hose is the rubber T-piece you can see in the photo

I felt around the back of the hose and could easily feel the split.

It is a rubber hose approx. 10mm diameter.

Great news Phil.

Golf looked nice though.......

:( Guess what. bloomin ASR light came on this morning for no reason and no fault codes are logged - Des "Delcac" has previous said this is a sign of a failed MAF - so it looks like I need to change it after all.

maf shouldnt be too bad money wise, i was quoted 80 euros by main dealer here for the exchange version... keep us posted

Surely the ASR light shows a failed ASR?

I agree, ASR light is likely to be the MAF. Exchange units from the dealer are around £60 IIRC.

My engine's lacklustre performance must have been down to dodgy petrol, but I've borrowed a very comprehensive set of torx bits to clean the MAF as a precaution.

My engine's lacklustre performance must have been down to dodgy petrol, but I've borrowed a very comprehensive set of torx bits to clean the MAF as a precaution.

You need security star bits to remove the MAF from it's housing. However if you plan on cleaning the MAF whilst still in the housing using a sealed bag and isoprpyl (the method I would recommend) then you'll be fine with just torx bits.

Perhaps you should write a tutorial, including photos etc. Eddy

Perhaps you should write a tutorial, including photos etc. Eddy

A brief guide would be:

Unclip electrical connector from MAF.

Undo Clip holding upper TIP section to MAF.

Undo 2 Torx screws attaching MAF housing to airbox.

Pull Maf housing away from airbox.

Get a watertight 'zip' top bag.

Pour some Isopropyl into the bag.

Place MAF housing into bag.

Seal bag.

Gently tip the bag side to side to 'slosh' the Isopropyl onto the MAF.

Remove MAF housing unit and leave to air dry.

Refit MAF housing by following the first 4 steps in reverse.

1 litre cans of Isopropyl are available from Maplins for around £10.

I'd only recommend cleaning if you suspect you're having MAF related problems and as a last effort before replacement.

If you have a DBW car and suspect the MAF is causing running problems then disconnect it. The ECU will then run in closed loop. If the cars performs better than normal then you have a faulty MAF. Running long term in this manner is not recommended as fuel economy will suffer.

Thanks Eddy, I'll disconnect mine this evening and see how it goes in the morning.

i spryed mine with carb cleaner not that it looked as if it needed cleaning... there was no obvious dirt or grime.. made no diffrence... also cleaned throttle body.. that made no diffrence either... its at jabba on the 4th so hopefully might get resolve or at least get a diag of the problem....

Joel

I personally wouldn't use a spray due to the delicate nature of the MAF. I have heard of others using this method though. I suspect if using a spray an electrical contact cleaner maybe more suitable.

Agree with Eddy...Isopropyl in a bag.

I'm not sure how safe using a spray is though as the MAF is quite delicate...well the heat wire inside is.....I think.

Ther's a "How To" on one of the other sites....probably UK_MIVs.

Surely the ASR light shows a failed ASR?

You do get some strange warning lights come on sometimes for completely un-related issues. When my brake light switch failed I got the yellow coil light on (glow plug heater) on my Superb!!

Also, in this case, the ASR is still working when the light is on.

:( Guess what. bloomin ASR light came on this morning for no reason and no fault codes are logged - Des "Delcac" has previous said this is a sign of a failed MAF - so it looks like I need to change it after all.

Also told you about the silly little hose under the manifold..........Actually may not have been you.

Dont think it was - though Ross did tell me weeks ago

Dont think it was - though Ross did tell me weeks ago

Ah, it was Mr Jutel, Post 7

http://www.briskoda.net/forums/ask-tech/41983-lack-power.html?highlight=manifold

Same thing happened to me. If you look inside the hose when it's off, the whole pipe is corroding.

Perhaps you should write a tutorial, including photos etc. Eddy

I remember seeing a tutorial before with pics, I thought there was linked on Brisky somewhere about it