Now i dont usually use the cossie if its raining but sometimes you just get caught out dont you? yesterday when i was out it started raining while i was on the motorway and the car started missing on full boost then when the rain stopped after a while the car was back to normal. anyone any ideas?

 

Mine is doing something very similar! Went out today in the rain and it's missfiring like a twat; not on boost though, it's fine once the turbo is spinning!
Have you still got the 2 multi-plugs on the near side inner wing? I think they may have something to do with it??????????

 

What he ^^ said, or could possibly if heavy rain going through louvers onto ignition system?

Martin

 

Check if the car has the tray under the engine. My friends BT did the same & we think it was due to rain getting into the engine bay & affecting the Dizzy. His was missing the tray.

 

first point of call would be to check the wiring deterioration within the 2 big multiplugs on the passenger side inner wing.
you wont go far wrong in having them cut out and bypassed.

 

Mine has a boost problem when on full boost but only in 5th gear (90mph+) I adjusted the crank sensor as there was about a 5mm gap and it's slightly better. Thinking about it now it has only started since i removed the undertray to change the oils. Maybe its a coincidence or maybe the undertray keeps the wind from effecting sensors????

 

Could be worth refitting the tray to see if it fixes the problem, cheap fix if it does.

My ST is fine no matter what the weather & doesn't run with a tray as some monkey at a garage didn't refit.

 

Thinking about it the vents on the bonnet are designed to pull hot air out of the engine bay at speed & vent hot air when parked up after a run.

With no tray on & the car on the move it would pull the air from under the car, which when its raining is very very damp