Overboosting Spyder

[97 Talon Esi]

I am posting this for a friend of mine. We just finished replacing his engine block in his spyder,old one had thrust bearing failure. The car is completly stock with t-25 it is also a 5-speed. The problem we are having is that while we are driving the car down the road the boost will increse at a fast rate an will have little power while under boost. The car runs great while not under boost, we did have a few boost leaks from lack of tightening clamps down but we have corrected them an did a few more BLT's an all is fine. I have done many BLT's an even the old fashion way with a can of carb cleaner. We then moved on to the Wastegate solenoid, swapped out 2 of them still no fix. Triple checked every single vaccum line to make sure we didnt cross anything. I wanted to add I know for a fact the turbo is spinning an I am not getting any smoke or strange noise coming from it. We then checked the actuator an it is moving properly, The car idles so good an it purrs like a kitten we are completly baffled on this an was hoping I could get a better knowledge of what I might be over looking ? Also I did notice when I pulled the vaccum lines off at the solenoid I feel no vaccum what so ever coming from it when i put my finger over it. I'm not sure if it only see's vaccum under load or not ? I been trying to tell him forever to get a real boost gauge so we can actually see where we are hitting for psi but unfortantly we are stuck with the POS stock one so sorry for that lack of information.

 

[Bud92gsx]

If he's going to have a turbo car, get a freaking real boost gauge..

 

[agentorange313]

I am posting this for a friend of mine. We just finished replacing his engine block in his spyder,old one had thrust bearing failure. The car is completly stock with t-25 it is also a 5-speed. The problem we are having is that while we are driving the car down the road the boost will increse at a fast rate an will have little power while under boost. The car runs great while not under boost, we did have a few boost leaks from lack of tightening clamps down but we have corrected them an did a few more BLT's an all is fine. I have done many BLT's an even the old fashion way with a can of carb cleaner. We then moved on to the Wastegate solenoid, swapped out 2 of them still no fix. Triple checked every single vaccum line to make sure we didnt cross anything. I wanted to add I know for a fact the turbo is spinning an I am not getting any smoke or strange noise coming from it. We then checked the actuator an it is moving properly, The car idles so good an it purrs like a kitten we are completly baffled on this an was hoping I could get a better knowledge of what I might be over looking ? Also I did notice when I pulled the vaccum lines off at the solenoid I feel no vaccum what so ever coming from it when i put my finger over it. I'm not sure if it only see's vaccum under load or not ? I been trying to tell him forever to get a real boost gauge so we can actually see where we are hitting for psi but unfortantly we are stuck with the POS stock one so sorry for that lack of information.

Sorry man, that is your problem. Stock boost gauges are inaccurate and NOT a reliable source of information for your car. Its all qualitative information. Tell you friend to get a new one AGAIN and for real this time, find out what your cars vacuum is at idle, and move on from there.

have you check your timing since the rebuild?

 

[97 Talon Esi]

Yeah I have been telling him since he bought it but I think I have better luck talking to a brick wall on that topic. As for that timing I forgot to check that but from what I read the 2g's don't have an adjustable CAS, but I will check that out. Sometimes I don't even know why I fix his car for him, he is rough on vehicle's but i'm already involved so no backing out now.

Correct me if i'm wrong but doesn't the car only pull timing when it sense knock. I know when we put this together I made sure that all the marks for the timing belt were dead nut's on. I just don't understand how base timing would affect the boost ? Would'nt the engine run like shit also. Sorry for all the questions but I love to learn new stuff I don't know about, so if someone could shed some light on the subject that would be awesome !!