dump valve problems

[Johnerz]

Hi folks,
after leaving mot centre today my dump valve stopped working, heres a timeline
 
left mot centre after failure, low revs in 1st
accelerated to about 2000-2500 and shifted into 2nd
as i tried to accelerate more the car wouldnt rev past 2500
car exhaust sounded spluttery and you could here a hollow spinning type sound
 
car revs freely in neutral, but no dump valve sound
 
hopefully a loose/broken/craked hose? (more like please please god only be that)
 
any thoeries or if you need any more info let me know!  cheers

[Alex T]

have you tried calling the MOT station and asking them if they have tried removing/bypassing something to maybe alter something, ie:emissions?
only a thought, if a non friendly rx7 garage this is!

[Jono FD3]

if it faild on emisions, it could be your cat has desided to fall apart & create mega back pressure (resulting in a very labord reving!!)

Only other thing I could sujest is check all your pipes on the intake!!

Jono

[Johnerz]

ill be checking that tomorrow mate, the car was fine before it went into mot and passed emissions no probs at all.  hopefully it is just the plumbing