850R missing and backfire

[kyboy]

Hi there all,as above missing on HARD acceleration but fine if you build up speed gradually and this morning it's been back firing and popping more than usual is it over fuelling?? Plus boost leak?? Apart from this runs fine but is driven hard daily....ta!

[mitchyboy01]

Sounds like it could be an ignition fault with the hesitation and back firing.

[martin_r_smith]

What plugs have you got in there and how old are they?

[kyboy]

What plugs have you got in there and how old are they?
That's my first call going to do cap arm and plugs as they haven't been done for a while!

[martin_r_smith]

Use volvo plugs.

[kyboy]

Use volvo plugs.

That's the plan just to be sure

[kmb]

I just cured a very slight random mis-fire on my 850 T5 by replacing HT leads, rotor arm and dizzy cap (all OEM), the plugs had been changed 3k miles ago with Volvo originals...