I looked through the forum but couldn't find a definitive answer. I am boosting well in all gears but 4th where the turbos won't reach full boost and the car falls flat on its face. The precontrol and wastegate control solenoids were replaced a year and a half ago I believe. I just replaced the transmission and did not have this issue prior to doing the work (not saying this has something to do with it but just giving background). Does anyone have an idea of what the issue could be?

The car has the stock boost controller and a PFC.

Also, I'm tempted to install a electronic boost controller I have to see if it will remedy the issue. If I set the boost to what the car was tuned for would there be any issue with not retuning it after installing the EBC?

Thanks

Ryan

 

Could be a turbo control issue. My car would sometimes randomly have the turbo control door stick closed, a new turbo control solenoid solved that.

Is it just when you get on it in 4th, or if you run it through the gears into 4th it is just flat when you get up there?

Dale

 

It happens when I am accelerating hard and shifting through the gears. I'll be in third accelerating and shift to 4th and the boost drops and the acceleration slows dramatically. Excuse my ignorance, where is the turbo control door and which solenoid operates it? The turbo system has never been my strong suit.

 

Bump

 

Turbo control is the lowest actuator:

http://www.autosportracetech.com/RX-...erOverview.htm

It is controlled by 2 solenoids on the rack. One is for vacuum and the other is for pressure to move the actuator quickly. Both need to function for proper operation. However, you typically see a problem with this actuator in the lower gears, not the upper gears.

You do not have boost issues in 3rd or 5th gear?

 

Yes, 3rd and 5th boosted fine. I forgot to mention that the drop in boost in 4th occurs after the transition point at 4500rpm.

 

Well I was wrong about 4th gear, its a 13-7-10 boost pattern in all gears. Any usual suspects? I saw that the charge control actuator could be a cause but it seemed uncommon, could it be a wastegate or precontrol solenoid?