boost problems + idle

[JohnP]

hi guys.. couple of problems..
 
1.  ongoing hesitation at top end.. can someone tell me about these one-way valves around the turbo/Y-pipe? and what symptoms i\'d get if they were narf\'d... i get 12psi boost from first turbo, then it falls back to dead on zero at 5.5k rpm.. this is an intermitent fault.. and usually better when the engine is colder.
 
2. fitted boost gauge, getting bouncy readings at idle... which made me panic and thinks rota-tips, but it clears up once the cars warm..  do the seals expand when they get hot and should i be panic\'ing? cars only done 28k miles...

[arrouk]

1. sorry bud its not as easy as thats but could be connected to 2

2.yes almoset every thing expands when its warm, if you have an unsteady vacume at idle but the engine revs are steady i would get to a specialist and have it checked, and no more boost untill you do.

sorry
matt

[JohnP]

ah, the engine revs r up and down too.. could be a simple prob like whatever the rx7 equivalent of a choke is playin up..
 
has any1 else had trouble with the one-way valves?  like i said, it boosts fine on the primary turbo, engine smooth as kate beckinsales arse.. its like the first turbo cancels out the pressure from the first turbo.. so would i be right in thiking the one-way valve on the primary turbo is nackered?

[ianelvar]

Could be along the right lines. The valves can be checked by taking the pipe off and blowing/sucking through them. There\'s a direction arrow on them.

Hunting at idle can be caused by coolant level being low and the ECU temp sender doesn\'t get a good reading.