Gti6 missfire

[boldy205 74]

Hi, it's a bit of a shot in the dark but hopefully someone came help me out.....

I've got a Gti6 low boost rotrex in my 205. This has been fine for a few years now, however I've noticed the last couple of track days that just before I need to change gear (aprox 6000RPM)  the engine misfires,  almost like the limiter coming in early.

This happens in straight lines with any amount of fuel in the tank.

I have a swirl pot set up with appropriate pumps for the fuel demand which are relatively new. 

I've tried new coil packs, only other things are crank sensor and cam sensor ?

Thanks!

 

Matt

[boldy205 74]

Just a thought, I've still got standard gap (0.8mm from my very vague memory) on the plugs. Any disadvantage of closing them up a bit?

[Tom Fenton 1,525]

How old are the plugs? 

Have you got a wideband lambda fitted?

[boldy205 74]

Plugs are maybe 2 years old, but have less that 500 miles on them. Good idea and worth fitting a new set.

[petert 550]

I've had issues with the cam sensor at the track, breaking down as you've described. I always carry a spare now.

[boldy205 74]

Tom: No wide band fitted, I guess to see if it leans out? If I was to fit one, do you know if i have to weld an additional  boss or can I use the existing hole and use one lambda for both ECU and wideband?

 

Peter: I'll grab a cam sensor and take it with me to the next event,  thanks!

[James_K 6 1 Cars]

I had a hesitation issue on my gti6 that stopped it revving above 5500rpm, after changing everything it turned out to be a faulty alternator. Took months to work out what the cause was. Still not sure why it lead to those symptoms. 

Just a thought, if you've ruled out everything else 

[boldy205 74]

18 minutes ago, James_K said:

I had a hesitation issue on my gti6 that stopped it revving above 5500rpm, after changing everything it turned out to be a faulty alternator. Took months to work out what the cause was. Still not sure why it lead to those symptoms. 

Just a thought, if you've ruled out everything else 

Interesting,  I wonder why? Did you figure that out by disconnecting the aux belt and driving it, or just by swapping the alternator?

 

I'll bear it in mind. Fingers crossed I'll get time to grab the mentioned spares tomorrow. 

[James_K 6 1 Cars]

It was a few years ago, so not 100%, but I think I did take the belt off to test it

[boldy205 74]

39 minutes ago, James_K said:

It was a few years ago, so not 100%, but I think I did take the belt off to test it

I'll bear it in mind.  Thanks!