st...st..........st........stutter

[DONKEYT5]

Hi all, my car seems to be stuttering at about 4,000 rpm in 4th and 5th gear when pushed hard.........any suggestions??
Thanx, Don

[Justin]

Overboost or bad ignition components.

[volvotuning]

Yeah I think so too, but first things first, read the fault codes!!!

Adam.

[DONKEYT5]

She seems to be boostin fine,(1.2) and also doesnt stutter everytime, only sometimes, recently had magnecor leads, new dizzy etc.........can u read codes if no etm is showing?
thanx, Don

[swordy21]

Don,

I get this too, and have been at a loss to explain, I get no codes on my reader - but maybe that don't work. Initially thought it was an air leak in the vac system, found one and got a bit better, but still a bit stuttery.

Does yours puff smoke out the back after stuttering. I've seen this a couple of times, and looks brownish in colour (unburnt fuel). TBH I'm leaning towards ignition comps, as the tick over is a bit lumpy as well, you can feel it through the floor of the car as a slight rumble. I did a stage 0 tune back in March, but that was 20K ago, Had the plugs out about 7K ago and they were fine (just as the stuttering started). According to my boost gauge I get up to 1.2 bar then drops to 1.1 and holds, however if it is gonna stutter it does that before about 1 bar. I have hit the boost limiter before, (on the Newbury bypass one cool evening in D3) boost slammed straight up to 1.3 bar and bounced off the limiter, feels different, much faster stutter.

Anyway gonna look at plugs, dizzy and rotor again. Change them one at a time and see.

BTW do the ignition coils fail on these cars?

Cheers