Hi all, my girlfiend has a s2 turbo (E reg) and its got a problem when the car is under load just when it starts to boost it starts to missfire and smells of fuel i have changed all sorts on this car and still no further forward its had new fuel pump and filter - new distributor,plugs and leads and coil, i am a qualified mechanic but this thing has got me baffled its completly standard apart from a s/s exhaust and a dump valve the only thing that i have noticed is there is a thing down near the rear of fuel metering unit has 2 fuel pipes on it and on the other end it has where i am surmising a vacuum pipe goes on to it i have looked all over and carnt find a pipe hanging anywhere cud this be the problem ??? Any help wud be appreciated as i'm at my wits end havent got a clue whats up with it if you drive the car trying not to boost up it drives fine just when the boost cums in it starts to missfire/backfire
Thanx in advance Kevin

 

Thats the fuel pressure regulator and there is no pipe missing, it's left open to measure atmospheric pressure.
Could be the actuator is not holding boost, the amal valve is cutting in and out, there is a split hose opening up under pressure, or even a problem with the Ignition ECU.

Karlos.

 

is it overboosting? Is plugs gapped right?

 

Thanks for the replys i'll have to check the hoses then. I'm not sure what the gap on the plugs are supposed to be lol has anybody got that info for me, I was told the plugs came already gapped correctly for the car as for overboosting i'm not sure when is missfires back fires it stinks of petrol but carn't find any evidence of fuel anywhere dont really know much about these motors so not 100% what overboosting is, what cud cause overboosting ??

 

IIRC plug gap is 0.9mm but just check in the Haynes manual to be sure, overboosting is when your boost rises far above what it is set to. If her car is standard then it should boost to 7psi (ish) anything higher than that is overboost.