What is the most likey cause of overboosting...??? Car was running fine now its overboosting all of a sudden.

 

amal valve controlls the actuator electronically.

Also check the vacum pipes from plenum to amal..then from amal to turbo if any come off or split then actuator will not open when it should making it overboost.

Cheers
Dan

 

Are you sure its overboosting and not a normal mis-fire?

 

Use to boost to 1.4 bar now its peaking at 1.7 and holding 1.6

 

when i first got mine on the road there was a pipe off the amal valve, the one that goes to the actuator, it was tring to boost 30+ psi, went like it had a rocket up its arse untill it missfired!

 

What problem does "overboosting" actually cause?

 

fuelling is not set for extra boost = melted engine worst case scenario!

If its extreme like my was, then its not really good for anything, the turbo is just boosting what it can, no actuator control at all, could result in dead turbo and engine.