markevans

Hi

I have a dax rush with a 2wd sierra cosworth engine runing about 300bhp. Just had a service new plugs, leads, cam belt etc etc. When nailing the throttle pulls like a train and back end snakes all over the place and pulls to 5000revs then stutters coughs chokes and misses change gear and away we go agian any ideas what would cause this only seems to happen at 5000 revs ticks over fine and no missing or stuttering before 5k.

any help ?????????????????

A.Moore

Is it normally aspirated or turbo?????

markevans

Turbo

A.Moore

It could be missing due to 'high' boost blowing out the spark.Check your boost and check your plug condition and gapping as this is critical on a YB lump,as alot of people seem to overlook this.

markevans

I have spoken to my cosworth tuner today and he has told me that the electronic speedo speedo could be miss reading and that it could be hitting the rev limiter (rev counter reading 5000rpm but actually engine is doing 6000rpm) thus hitting the rev limiter a causing what seems to be a cough stuttering??????? It has just come off a rolling road and he said that it was fine and that was only 60 miles ago

boost mad

iTrader: (8)

are u running a T5 box aswell? if so what speed in what gear is it doing this?

markevans

Yes runing a t5 gear box have not noticed what speed but can only go to 5000 revs in 1st, 2nd and possibly 3rd as it starts to blow your ear drums apart and going to 5000 revs in those gears is very scary stuff what was you thinking ???

boost mad

iTrader: (8)

was just gona go by rough speed in relation to ur revs, as if it was 1000rpm out there would be a fair differnce in speed

markevans

that would be a start for me to look at can you give me some speed relations to go by maybe 4000 revs and 4500 revs in first second and third

thanx