Replaced MAF - still got a idling problem :(

[kineticz]

Misfire on idling

Hi all,
My car misfires when idling and gradually reduces rpm until about 500rpm where it tries to cut out and jumps up abit then cuts out. If I rev it hard to say 5k rpm there is no misfire. If I rev it very slightly the misfire gets worse

The car hasn't been driven for a while. Maybe a long drive could cure this and clean something out? Or is that not possible and maybe a component is failing? Idle control valve perhaps?

vag com brings up no errors for this. If I remove the maf sensor the idling cures very slightly but it still misfires.

Any thoughts would be great

Thanks,
Dan

 

[Nutkin]

if removing maf helps then change the maff, never hurts.

what engine is yours. and are you the same guy from Talk audio and ccuk?

 

[kineticz]

Yes mate I'm on those forums =]

It's the 1.8t 20v Sport engine

 

[Nutkin]

.

I am Nutkin

anyhow, could be some spark plugs need changing and leads. heard them going a bit, coil packs too. have a lil search

 

[kineticz]

Wouldn't that cause misfire while driving though mate? As when driving it doesn't misfire

Also where are the plugs located please?

 

[traumapat]

sticking throttle body?

 

[MrJohnnyB]

I had a problem like this on my cordoba ages and ages ago, was oil on the air intake or something similar! I was 99% sure that this couldnt be the problem but my mate assured me it was and he actually was right for once. Probably not at all related, but figured id give my 2pence of knowledge.

 

[kineticz]

Do you mean oil inside the intake pipe connected to the MAF mate?

 

[Nutkin]

oil on the air panel clogs the maf normally.

 

[MrJohnnyB]

Do you mean oil inside the intake pipe connected to the MAF mate?

yeah, or similar, seeing as the cordy i had was too old to have a maf it was around the location the MAF would be. To be honest though it doesnt actually sound (well to me anyway, and im just going by what ive read) that the MAF has gone. But who knows!

 

[kineticz]

Hey,
Today I fitted another maf sensor hoping this would cure the irratic idling and overfueling problem - however it hasn't Unplugging the maf cures the idling but obviously it runs with severely reduced performance.

So can anyone suggest what else it may be? I ran a scan with VAG com and it came back with two faults: Coolant temp sensor signal too high, and lamba sensor signal too high

Many thanks for any help
Dan

 

[DPJ]

Replacing the coolant temperature sensor should solve it (and get rid of the lambda problem)

 

[Jimski]

i gave mine a good squirt with some carb cleaner, and its ran better ever since. Throttle body plenum covered in crap and not shutting/opening as efficiently as it should.


Jimski

 

[kineticz]

Replacing the coolant temperature sensor should solve it (and get rid of the lambda problem)

Do you know what price I'm looking at and possibly also a part number please? How do you remove it?

Cheers!

 

[DPJ]

NEW/Updated - Temperature Sender (Green)
Part#: 059-919-501A

O-Ring
Part#: N90316802

Loads of threads telling you how to swap it.

 

[kineticz]

Just found a guide to replacing it and am gonna ring the dealer to order the part

Hope this cures it! Will let you know.

 

[kineticz]

Do you reckon these parts will be available from my local VW dealership? As it's much closer than the Seat one

 

[kineticz]

DPJ, I spoke to a guy in the VW dealership and he said he's not heard of coolant temp sensor causing idling issues - only problems he hears of is issues with cold starting on diesels mainly. He does have them in stock - at £28.50! :O

Is a faulty coolant temp sensor actually known to cause rough idling? And why does the idling fix itself when I unplug the MAF if the MAF isn't at fault?

Cheers

 

[traumapat]

have you cleaned your throttle body? I`d do the cheap stuff first.

 

[DPJ]

DPJ, I spoke to a guy in the VW dealership and he said he's not heard of coolant temp sensor causing idling issues .......

I'm not goint to even bother answering that.