Gti6 Misfire At Light Throttle Under 2K, I've Tried Everything

[Paul_13 212 1 Cars]

But stuck on this one.

I've got a persistent misfire under 2k with light/medium throttle. If I plant foot straight down it does mostly disappear.

Feels like it's only firing on 2/3 cylinders.

 

I've changed :

Coils (all of them)

Plugs

Camshaft sensor

Lambda

Unplugged tps (still does it)

Maf sensor

 

Any body got any ideas?

My thought was fuel pump but I don't think it is. Top end isn't affected

[welshpug 1,675]

Compression test?

 

What do the plugs look like when its doing it?

Edited May 18, 2014 by welshpug

[Paul_13 212 1 Cars]

Plugs look normal when I changed them.

 

I'll do a compression test when I get the chance

Edited May 18, 2014 by Paul_13

[Paul_13 212 1 Cars]

Well I've just reset the ecu and unplugged both the ecu and double relay to check there's no corrosion.

I had a problem ages ago thinking about it where after plugging the ecu in, the car would only fire on 3 cylinders. I unplugged the ecu, gave it a blow out and it started fine on all 4

[Paul_13 212 1 Cars]

That didn't do anything

 

I just new bought a set of brand new of ngk plugs if it is them. I know the likes of Miles doesn't like /use Bosch super 4's

 

But you have got me a bit worried Mei, the engine was stood for quite a while and my mate put loads of oil down the bore. I'm wondering if one of the rings is sticking.

Or I did fry the HG when I split the hose on the way to work. It didn't go into the red though on the gauge.

[Paul_13 212 1 Cars]

Plugs didn't do f*** all

 

Would a dodgy knock sensor cause these symptoms?

[calvinhorse 870]

Try unplugging the lambda, cheapo ones fail really easy and fail in a way that they cut the fuel off rather than just stop working.. Had me scratching my head for ages

[Paul_13 212 1 Cars]

I have mate, made no difference

[kyepan 291]

Is it intermittent or all the time?

Just read the op, all the time.. Perhaps a very slight air leak down stream of the afm

[welshpug 1,675]

Is it intermittent or all the time?

Just read the op, all the time.. Perhaps a very slight air leak down stream of the afm

 

what AFM?

 

but indeed, worth checking the inlet manifold gasket and the injector o-rings.

[Paul_13 212 1 Cars]

I've got some easi start at home should be easy

[Tom Fenton 1,561]

No no no, you need a tin of this!

 

[welshpug 1,675]

not available in the uk any more I think, but its bloody good stuff, I think its the Ether content

[Paul_13 212 1 Cars]

[camgti 56]

I had a similar problem. Have you reited the ICV? These can cause your symptoms at low revs.

 

Otherwise sounds like an air leak somewhere.

 

Cam

[Paul_13 212 1 Cars]

Yep I've changed the icv as well

[welshpug 1,675]

throttle bodies it is then.

 

 

 

 

[Paul_13 212 1 Cars]

Don't tempt me.

All I need is the mani and ecu etc my mate has a set of red jenvies

[kyepan 291]

you've been saying that for the past two years.. need to take you for a spin to tempt you

[huwjones 0]

Is this fault worse when cold?

 

Have you got an alarm/immobiliser fitted?

 

I had a similar problem with a VTS conversion but never found it!

[Paul_13 212 1 Cars]

I found out what the fault was.

 

My speedo died earlier, I think the vss has burnt out again and low and behold the misfire has gone!

 

Vss was f***ing things up all along, looks like I need a new loom (throttle bodies) ;p

[Miles 331 1 Cars]

Funny this as I had almost the same thing, but caused the engine to cut out for no reason at various points and times, Unplugged VSS and all is good

[jcsh 0]

Funny this as I had almost the same thing, but caused the engine to cut out for no reason at various points and times, Unplugged VSS and all is good

 

What is a VSS ?? cos this seems exactly the problem that I have...

[Anthony 1,003]

Vehicle Speed Sensor - the electrical part of the speedo drive that tells the ECU how quickly the car is moving

[jcsh 0]

Finally found a computer again -- My car is in NZ and I'm now in Europe ... Thanks for the help so far in identifying this V annoying problem!

 

So ... This VSS thingamajimmy, .. Would the GTi6 gearbox (as fitted) have the same VSS as the old 1.6 gearbox (lying in my shed) if so then great as I can swap them around and test them when i get back - If not, then I should probably try and get hold of one before I go back - does anyone have one lying around they don't need...?

cheers

james