my s2 holds back but then if you back off then boot it again it will go like hell any one have any ideas

 

knock sensor is retarding the igntiion. CHeck the connector and tighten it up on the manifold. Also, try unscrewing it from the manifold, insulating it from noise, and tucking it away in the heater box. It MUST be electrically connected.

 

knock sensor on rst ?? you mean amal valve or what?

 

no, the knock sensor.

 

The rubber pipe from the airbox to the centre (suction) side of the turbo can collapse when it gets old. This strangles the turbo - grab this pipe and give it a squeeze - if it collapses easily then that'll be worth replacing. Get a samco on it.

 

i have been told to try the knock sensor i was told to unplug it so i did and still the same

 

where is knock sensor placed??

 

Does the car die - or just holding back like a missfire ??
The boost can blow out the spark.

Has this come on gradually ?? or just happened one day and now does it all the time ??

 

rs230

if u unplugged it and it drove the same, then it is defo the knock sensor.

 

where is knock sensor placed?

 

right hand side of the inlet manifold green plug

 

yes its on the right hand side on the inlet mainifold and if i pull the pipe off the dump valve it will keep holding back then put the pipe back on and it will go fine. Then after a bit start to hold back again

 

its not a missfire just like a flat spot when its right it will spin no probs in 3 but when its playing up will hardly spin in second

 

i am having the same problems , just took mine out today for a run, it runs very sluggish in 1st and 2nd, it ticks over ok and revs up no problem, took it for a blast on the motorway and still seems to hold back. it did this last year, so stu at msd put on a second hand top boost hose on it , might have gone again ???

 

Such a common problem on MFI cars

Its also worth checking the operation of your TPS. My first RS had a similar symptom which was very noticeable in 5th, my TPS was intermittently faulty, seemed fine after i replaced it