Hi there i have 1993 twin turbo rx-7 i got a big problem, when i get on the car the first turbo kicks in but when it gets to about 4k rpm it falls flat, no more boost the secondary turbo does'nt kick in, does anybody know where i should start looking to fix these problem? thx you in advance

 

Can you hear the turbo's spooling still? I had this problem with my old car (a 95 VW Jetta Turbo Diesel) it ended up being my wastegate starting to open early and sticking open when not under load. Not so great when you're (supposed tobe) running between 18-20Psi above 3k Rpm

I would start by checking all the Boost/Vaccum lines on the turbos and go from there. Also, get some one to rev your car while its parked, you wont get the same results from the turbo as when driving but pay attention to the wastegates. Or test them manually, it should take a bit of effort to move the acctuator rods but not more then you can handle.

Have you installed a boost gauge? if you have make sure the t connector you've installed isnt leaking and you MAY want to get a second for the secondary.




Good luck.

 

what do mean falls flat? does it boost when its getting up to 4k rpm? does the gauge show no boost past 4k rpm?

 

when it hits 4500k rpm it quits pulling and on the boost gauge goes to zero, I think the pre control solnoids are out .

 

It's probably not the wastegate or precontro.

First check to see if you're getting vacuum and pressure stored in those two tanks. The vacuum tank is tucked under the alternator and the pressure tank is above it. Just drive the car and pull a line leading to each one (you'll need long reach needle-nose pliers). If you don't hear the hiss, you'll need to figure out what is leaking it out.

A bad check valve, broken plastic nipple, loose hose, torn hose, all very common issues.

David