My friends 94 RX7 has the following problem. Here is a paste of his last email to me:

"I found a long quiet stretch of

road and managed to get into 4th gear and ran it up to 120 mph and 6300

rpm and the car wouldn't exceed it. Same problem as before in the higher

gear now. I assume its the same in 5th."



Any idea on what's causing this problem with my friends FD?

He had Mazdas Plus check it out and they found some brittle and broken vacuum lines to the turbo and replaced them but the problem persists. I'll try to get my friend to join our little group here but meanwhile thought I'd run this by you guys.

 

i'm gonna say he has clogged precat or main cat if they are still on the car..... check that out, very common on FD's

 

Tell us what mods he has. THat may help in diagnosing the problem.

 

Sure, well that's easy. He doesn't have any mods. Totally stock 94 RX-7.

 

i'm gonna say bad vacuum hose or actuator or solenoid. or my first guess clogged precat or main cat

 

What exactly happens at 6300 PM, besides the obvious?

 

Boost gauge? What is the boost pattern?

 

Well my friend took his car to my mechanic and I think they found the problem. They replaced a valve that controls the vacuum to the Turbo. So looks like Vosko whas right with his guess that it might be a solenoid or acuator to the turbo. But the mechanic agreed that clogged pre-cat or main cat could have also caused the problem by causing backpressure.