Boosting problems

REAL-DEAL GN

1987 Grand National T-TOP
Joined
May 24, 2001
First of before i go into a long story my mechanic said my cam sensor is making noise and should be replaced. My problem is when I TRY to power brake my boost goes up to 5 pounds and stays there, until it feels like going up to 13 pounds. I ran a 15.50 @90mph. The car felt real good upstairs but I have this out of the hole problem. I don't have an exhaust leak major enough to cause this problem. I pulled off the boost sensor hoping for over boost, nothing, with the boost sensor off I figured it would over boost, it still only gave me 13 pounds with the sensor off. How would i know if the cam sensor is 180 degrees out? I'm going to buy a cam sensor today, how do you set it. What else should i look for, I'm getting no back firing or nothing. Thanks.
 
What turbo?
With the solenoid disconnected, you are limited in boost to the amount of pressure in the spring of the WG actuator, which is 13# if you have not shortened the WG rod.
If the rod is adjustable, shorten it up a bit and it should increase the WOT boost...but won't help the spoolup.
The puck may not be seating correctly over the puck hole in the exhaust housing....spoolup will be slow anyway when running tuner style (straight vac line from compressor to WG actuator).
May just be the characteristic of the turbo you have its its very big and low stall convertor.
Running rich will also cause slow or lagging spoolup. A leak in the exhaust before the turbo will allow air to be sucked in and the O2 will think you are lean and add fuel, thus really causing the fix to be super rich....so a little exhaust leak before the turbo can really hurt spoolup.
 
everything is stock

Thanks for the reply.

Everything is stock except for the chip. It is an old kenny bell 93 chip. A friend of mine said he thinks its the torque conveter not stalling at all, and not allowing the turbo to get into boost. I'm not sure what I need to do first. I don't want to try to fix something and mess up something else. What does it mean when they say the cam sensor is 180 degrees out? And how would you know if it's wrong. I unplug mine while the car was running and i heard the injectors clicking really loud!
 
I assume that you are looking at an aftermarket boost gauge and not the stock LED that is probably off. If you exhaust goes to 5# then lags up until 13# you may have a pre-turbo exhaust leak, you could be running rich, your TC may not be unlocking, you may have a plugged 18 year old cat, or possably a leak in one of the intercooler hoses. At least there is a good start at what to look at.
If you didn't mess with your cam sensor, I don't see how it could be 180* out.
 
Yes, the cam sensor can be disconnected after startup and it will not effect anything. Only used at startup.

If the convertor is not unlocking, it will show sign of this without being under boost. Like when coming to a stop it will lug hard, once locked, you can slow down, but do not stop ..just slow down to about 10mph or so, then slowly accellerate...not enough to produce boost...and it will drag/lug real bad...like something heavy is tied to the back of the car kind of feeling.
The lockup solenoid is easy to replace...if thats what it needs, any do it yourselfer can do...there diagrams and instructions all over the net.

I still suspect a pre-turbo exhaust leak.
 
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