First turbo only works if second has come on boost that gear?

[GhostWKD]

Sorry for the long title firstly
 
Picked up my new Rex off of Shark yesterday and love it though after i had brought it home i went to take it out and found that i dont have the first turbo working, have done some searching here and found others stated their first turbo worked when second had come on boost and revs were still 2k+ in that gear so tried this and sure enough the first turbo worked 100%
 
On the search most of the threads i have found havn\'t had a solution stated though i have read that it could be due to a one way valve in the rats nest?
 
Can anyone confirm this at all?
 
Cheers,
Alex

[shaunwil]

Could be a dodgy solenoid, bad one way valve or a leaking vac pipe.

What level of boost is the car running when you get boost ?

Shaun

[cush]

ok i have had this problem for ages now and no one could diagnose it and after about 7 hours looking on forum after forum and posts i have found what it is doing it.
 
TEST
start the car up and look at the valve that lets the second lot of boost through on the pipe coming from your second turbo to the y pipe.
it should be closed on tick over mine isnt so all your boost is going through the relief valve but when you get past a few revs it finally closes and you can build up boost until it opens and doesnt shut again.
i bet this is your problem it is not damaging anything i have not yet fixed it but you can then find the vacuum diagram and find out which solenoid valve and pipes that connect to that change them all and should be fine.
 
if you need more help email me at cushingx@hotmail.com hope i have helped i have had it for 3-4 months now not having boost all the time its annoying lol

[GhostWKD]

Could be a dodgy solenoid, bad one way valve or a leaking vac pipe.
 
What level of boost is the car running when you get boost ?
 
Shaun

around 0.1bar building up to about 0.3 by the time second turbo comes on at which point it boosts to the normal 0.9/1.0 bar on that turbo
 

ok i have had this problem for ages now and no one could diagnose it and after about 7 hours looking on forum after forum and posts i have found what it is doing it.
 
TEST
start the car up and look at the valve that lets the second lot of boost through on the pipe coming from your second turbo to the y pipe.
it should be closed on tick over mine isnt so all your boost is going through the relief valve but when you get past a few revs it finally closes and you can build up boost until it opens and doesnt shut again.
i bet this is your problem it is not damaging anything i have not yet fixed it but you can then find the vacuum diagram and find out which solenoid valve and pipes that connect to that change them all and should be fine.
 
if you need more help email me at cushingx@hotmail.com hope i have helped i have had it for 3-4 months now not having boost all the time its annoying lol

Not looked at the RX7 engine bay Y pipe etc setup to be honest so will take a look at that when i get a chance :o
 
May well give you a shout once have had a chance to take a look at it all.
 
Cheers,
Alex

[shaunwil]

Could be a solenoid problem. Anything over stock boost levels of 0.7bar reduce the life of the solenoids forcing them to stick.

More likely a vac line has popped off, usually you would see more boost.

Shaun

[shaunwil]

What turbo are you running ?? The stock twins will only do 1bar with some fuel and cooling mods.

Shaun

[GhostWKD]

As far as i know its stock twins, running Apexi induction, Kakimoto (sp?) catback exhaust and has a Apexi FC which was mapped by Carl
 
Had a quick look around it but couldnt spot any visual problems though i didnt take the inlet plenum off (is this a big job?)

[GhostWKD]

Just had a quick look at FDowners.com and seems a easy enough job, will have a look at it tonight more than likely also look at taking it apart to check the Y pipe

[Bobbit]

Def sounds like a sticky solenoid.
I had a similar prob and a pressure regulator worked a treat. basically I set the regulator to 10psi and this stops any pressure over this getting to the control systems of the turbos and screwing them up, i\'m running 14psi and at that pressure the solenoids are next to usless so limiting the pressure that gets to them fixed my probs.
But only try that once your checked the one-way pills and the solenoids themselves.
Getting the phlenum off is not a big job TBH, just take your time and check EVERYTHING is unconnected before you lift it off, so many people have snapped nipples off the double solenoids (myself included), there is some info on how to remove it here bud: clicky

[Smifta]

What you describe sounds very strange.
Typically you will not see ANY boost from the second turbo if the first has not first hit 7 PSI. The fact you are making any boost at all after 4k RPM is odd (at least, not an issue I had heard of).

There are plenty of known issues and fixes for the second-turbo not coming on line. You\'re issue is the opposite though?!

I recommend popping down the A34 to Carl. I\'m pretty sure he knows this car, and has done the servicing on it previously.

[Bobbit]

The 1st turbo is making boost other wise the 2nd would not work, the boost is not going through the engine tho, so it has to be a control issue.

[DMDRIFTING]

Hello,

don\'t want to jump on your thread but i have the same problem with my 1st turbo.

No more than 0.16 kg/cm of boost on the 1st turbo through 1st 2nd and 3rd gear and no more than 0.05 kg/cm in 4th and 5th gear.

Once above 4k (most of the time sticking on 1st turbo) the second turbo the boost is 0.77kg/cm in all gears and flies along lovely :driving



What does this sticking and lack of boost on 1st turbo mean?

[Bobbit]

^^ Knackered solenoid bud, mind did exactly the same thing yours is doing, you need to replace the 2nd solenoid back (from the front of the car) with one that can hold the boost you\'re running.

[GhostWKD]

Did intend to take the car with me to Newbury on thursday (my works HQ is there) and see if i could pop to Carl while i was there but ended up taking the company car as was in meetings all day anyway so couldnt get out of the office unfortunately.
 
Bobbit when you say you used a pressure regulator what exactly was used?
 
Intend to take a look at this issue after i\'ve serviced the car this morning... now where did i put that spark plug thread :wiggle
 
Also forgot to mention but when so revving to 3.5-4k or so and letting off get a woosh of air kind of noise, sounds kind of like an owl? assume this is the air that should\'ve been going in my engine
 
Cheers,
Alex

[Bobbit]

have a look here bud: clicky