car juddering when full throttle
 

hi got a few problems with my turbo uk model ej20 block, when putting full throttle its pulling back like im pressing brake in juddering bad but if i only put half rev on til i get past 5k revs then floor it its straght there any ideas? been told it could be boost control thats gone down but unsure

Sounds like its over boosting.. any mod's like full exhaust or air filter been done without a subsquent map?

Do you have a boost gauge in the car?

Also could be surge perhaps DV related. Is it all gears or high gears?

As above or could be spark related, grubby or too large plug gaps, wrong plugs, coil packs depending on year of car.

Simon

???
 

its got a megnex exhaust and a dump valve thats all its ad done, its ok in first 2 gears then its buggers up, i ad sum shell super and it ran ok just holding back abit but not half as bad could it be down to fuel? can you ad high octane additive juddering i used jet super unleaded then it went juddering when getting past 3k revs but

its a 96 model

I too am having a similar problem in fifth gear when on full throttle, so will follow this thread! Let me know if you figure this one out

im starting to wonder about injecters and air mass flow sensor

possibly dumpvalve... try blocking it off or a known good one.. it is probably openning