Emissions fail MOT

[govaglee]

Hello

I just took my mk2 golf gti for an MOT and if failed because the hydrocarbon level is to high.

I have checked the air system but it has no leaks and changed the MAF sensor, spark plugs and set the timing up

But it is still kicking out fuel from the exhaust.

Does anyone have any other ideas?

[nitroscope8]

Not sure if they had catalytic converters, but id replace it if you have one or install one if you do not.

[govaglee]

They don't have cats and wouldn't it be to much work to install?

Anyway this doesn't solve the problem it will just hide it. Something is wrong in the engine and the fuel is not getting burnt somewhere.

[le0n]

...and set the timing up...

you've adjusted the timing to be something different than what its supposed to be? or you made sure it was timed properly.

if fuel is leaving the exhaust pipe and you can see it, my guess is that your system is also flooding the cylinders. you'll essentially keep them washed of any oil/lubrication and create more friction to wear your rings down.

is there black/white/blue smoke leaving your exhaust pipe?

why was the maf changed?

how is the idle smooth/rough?

welcome to the VWOC...

[govaglee]

I made sure the timing was correct although it is difficult as the revs are jumoing around abit.

To test if it was fuel leaving the exhaust I put a bit of mental infront of the exhaust and turned the car on. The peice of metal filled with little beads of clear liquid. I then put a lighter to the beads but the did not light.

Smoke looks normal to me. Not black and not blue just the usual white.

idle is pretty rough.

[le0n]

now it makes more sense. i'd suspect the plug wires. my first guess was plugs, however, you've claimed to have changed them. you're probably jumping spark somewhere on your wires.

edit: if you look under your hood at night while your engine is idling, sometimes you can see/hear the spark jumping from the plug wire/s to metal on the engine...

To test if it was fuel leaving the exhaust I put a bit of mental infront of the exhaust and turned the car on. The peice of metal filled with little beads of clear liquid. I then put a lighter to the beads but the did not light.

it's mostly likely just a miss then. for instance, let us say that there's a 75% chance that the plug with the bad wire actually gets fed enough energy to properly ignite the fuel. the other times, vaporized fuel gets injected and forced out unburnt or even partially burnt. you get exceptionally high HCs at your tail pipe. they won't be in liquid form, but they will be present in the exhaust gasses that escape...