Possilbe ECU Problem. Can anyone help?

[brendan]

I really need some urgent help on my MK4 GTi Turbo.

Yesterday my car started missfiring really badly and had no power at all so I had to pull over. I called the AA out and he diagnosed it with a scanner as Cylinder Number 3 missfire. I changed all the Coil Packs a month ago for genuine VW items and also the spark plugs. I pulled the coil pack out and put it back in, then started the engine and it started as normal. It then stayed like this all day with no problems, as I drove at least 80 miles yesterday. Great I thought, problem solved!

No, Maybe not. This morning whilst driving the car, the same thing happened again. So luckily I was driving past an auto electrics place near me and got them to have a look at it. Exactly the same problem again, so I pulled the coil pack out and put it pack in again. The car worked as normal.

He seems to think that there is a possible ECU fault, and that I need to get it on a proper VW scanner. I've also asked a few other places and they all seem to think the same. I'm worried this is going to cost me a fortune now as I don't like the sound of a new ECU.

The car will hopefully be going up to R-Tech later if I can get a lift, but in the mean time can anyone help me?


Thanks.

[T_J_G]

Dodgy wiring to the coilpack?

A VAGCOM scan will only show up the same as the AA fault codes.

[brendan]

I'm not sure tbh, it could be. Its very intermitant. I'm really lost now.

[T_J_G]

Have you tried another coil pack? It may be worth it, if it don't fix it you could rule it out and keep it as a spare in your car if any of the other ones go?!

[Rhyso]

have you swapped the coil pack from one cylinder to another?

if the mis-fire occurs on the other cylinder then you know the coilpack is at fault, if it occurs on the same cylinder then its possibly a wiring fault

[brendan]

Have you tried another coil pack? It may be worth it, if it don't fix it you could rule it out and keep it as a spare in your car if any of the other ones go?!

Yup I put the spare one in yesterday and it cured it, thought that was the end of it. Then it happened again this morning so I put the new one back in and its ok again.

[Rhyso]

Have you tried another coil pack? It may be worth it, if it don't fix it you could rule it out and keep it as a spare in your car if any of the other ones go?!

Yup I put the spare one in yesterday and it cured it, thought that was the end of it. Then it happened again this morning so I put the new one back in and its ok again.

sounds like a possible wiring fault then 

[brendan]

have you swapped the coil pack from one cylinder to another?

if the mis-fire occurs on the other cylinder then you know the coilpack is at fault, if it occurs on the same cylinder then its possibly a wiring fault

I've tried two coil packs in the same cylinder and it's happened twice now. Where do I start with the wiring?

[T_J_G]

Ah so it's got to be a wiring fault. That rules out the coil pack.

The witing runs from the plug across and down the back behind the TIP I think.

Mr_Orange changed his coilpack harness on here and got a heat shield from the Audi TT to stop the detiration again. Although I can't find any links.

[Rhyso]

Although I can't find any links.

This one