Second Gear, Secondary Turbo Issues
Second Gear, Secondary Turbo Issues
Ok I have done some research and came up somewhat empty handed. When in second gear after the transition my boost is dropping off to 5-6 psi but the part that gets me is once i shift into third gear above 4500 rpms I'm back up to a perfect 10psi. I know it can't be a boost leak considering what I just mentioned and the only other thing i can think of is maybe the charge control solenoid?
Thewird reported a similar problem on a single turbo FD. The vehicle would get high boost in every gear except 3rd. I believe in 3rd it would get 5lbs less. I do not think the problem was solved either. 
Turbo Control:
http://www.autosportracetech.com/RX-...leshooting.htm
http://www.autosportracetech.com/RX-...leshooting.htm
The Turbo Control Solenoid / Actuator is one of the more complicated actuators as it requires both vacuum and pressure to operate properly. This actuator is controlled by two solenoids, (both are wired together to the one ECU output) one solenoid applies pressure to one side of the actuator and the other applies vacuum to the other side of the actuator. With pressure on one side and a vacuum on the other side of the actuator, the speed of the actuator is improved. A typical problem is loss of Secondary boost in 1st or 2nd gear at 4,500 RPM, but reliable operation in other gears. This points to one side of the Turbo Control Actuator not getting it's pressure/vacuum, so it will still operate but not quickly enough.
No vacuum to the Turbo Control Solenoid / Actuator is a common failure. This is typically caused by the one-way valve that supplies vacuum to the Turbo Control Solenoid / Actuator through the Vacuum Chamber. The one-way valve will leak, allowing manifold pressure to leak into the vacuum while under boost.
No vacuum to the Turbo Control Solenoid / Actuator is a common failure. This is typically caused by the one-way valve that supplies vacuum to the Turbo Control Solenoid / Actuator through the Vacuum Chamber. The one-way valve will leak, allowing manifold pressure to leak into the vacuum while under boost.
holy crap Mahjik. I don't think it could have been spelled out for me better than that. Thanks a lot. Oh and that link is probably the most informative on our cars and dealing with the turbos that i have ever seen. I really appreciate it and it will definitely come in handy.
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CaptainKRM
2nd Generation Specific (1986-1992)
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Aug 26, 2015 09:52 PM
