Hi. I have turbo 2000 on a 2000 plate if boot the car it boosts fine till hit 4000rpm car stops pulling and judders until hit 6000rpm then goes back to to boosting again. I have checked the turbo and checked for any air leaks and that's all fine. Fitted a new maf about 3 months ago. Any body got any idea what could be. Been told could be lambda sensor??

 

Best thing to do is get it on a rolling road so a proper diagnostic can be done. Otherwise get the ECU checked for fault codes.

 

Check your plugs and leads mate

 

If was plugs or sparks won't it do it all the time and not just between 4500rpm and 6000rpm.

 

Not a mechanic but aren't plugs and leads/coil packs first thing you check? Other than that I'd go with what 360ste said

 

I have similar issues with my boost and after reading the fault code it shows faulty lambda sensor but until you just said it I totally dismissed it, didn't think this would have caused an issue with boost ?

 

Thing is that rev range is usually when the engine is at highest boost, once past 6000 it is more likely that the boost is tailing off. The higher boost will blow out the spark if the system is not up to scratch. One thing to do would be to take it through the rev range on light throttle whilst driving so the boost is not as high and see if it runs okay, then repeat on the same stretch of road giving it full throttle to see if it runs crap. Having done a low throttle run then a full throttle run on the same stretch of road will tell you there are no speed cameras just in case you accidently exceed the speed limit whilst testing. LOL

 

Do you have a boost restrictor pill ?

 

Yeah I have boost restrictor pill.

 

either of you sorted your issues?

 

and @gray I had the same problem with my cross over year scoob 95/96 odb1,turned out it was the plugs and (maybe) coils (mine are the 4 separate coils)

Also check your air intake to turbo pipe these usually split

 

My problem is solved fitted new lambda sensor today and problem solved. Cars running like a dream.

 

Yeah finally mine turned out to be the air filter, it was not letting enough air through so changed it and wow it's a whole new car lol