higher than normal boost before judder
 

Hi all, I though I sorted a problem a few months ago but have had it happen again today. Normally when cold and in 2nd gear ill pull out of the end of my road and put my foot down. I have the turbo kick in and where I normally feel the peak of boost I feel a little more (asssuming a boost higher than normal) before I get a miss fire, then drive fine.
I believe this to be an ecu instigated miss fire as its sensed an overboost. Both are present in the logs.
Any ideas guys. Is it going to be a stickly wastegate? Faulty boost controller? I'm guessing the higher boost or jolt or rise in temp sorts it.

Check that all the vac pipes are still attatched to the turbo

Yes, I also replaced them last time. Well the 3 that go from the top near the air filter(isn't that the boost controller?)?

boost controller is located on the side of the airbox

I got it right, yes I replaced the two down to the turbo and one short one to the airbox out. Ensured I got the the right way round too. Didn't just pull the all of at once... Boost and runs fine if or when it does it. Sometimes I can release the throttle before it happens as I feel a nice but over powerful 2nd gear. It's not a constant either. Gut feeling says something sticking or not opening.

Did you replace the plugs/coils?

If so those symptoms are typical of a faulty boost control valve.

See I don't think it helps that the car is an 05 and when I got her last year shed only done 29k. Think it had been driven by a "mrs daisy" so never problably opened the wasegate, hell probably never used the turbo?

Well I'm skeptical of garages. Bit but they did change them for me under warrenty and after my request. Helped at bit at the time, would coil packs be on way out again. So new controller then? They easy to get?

Or should I consider a manual boost controller?

Sounds like you can't be sure the garage changed the coils.

If it was me I would buy and change the complete ignition set
http://www.ebay.co.uk/itm/2307776836...84.m1423.l2649

If that doesn't solve the problem then I would change the boost control valve.I bought one recently as a spare,they are the genuine Rover OEM item but at half list price ;)
http://www.ebay.co.uk/itm/ws/eBayISA...m=260949412835

Those items should cover all possible causes of your fault.