hey I have a bone stock 88 turboII. when i open up the throttle, the boost gauge used to go up about 3/4 of the way up. now I cant even get it to go up to the "0" mark. the only thing i can think of that may be related is that about a week ago i switched to 93 octane gas (the previous owner used regular gas, which is what i had been using). On premium gas, the car runs better (it used to jerk a little on throttle transition until the engine warmed up) and it gets better milage. At first i thought i was getting a lot more power because it would accelerate much quicker without the turbo spooling up. now that i pay close attention, i can hear the turbo spool up before the gauge jumps. it still feels like it has plenty of power, but my gauge doesnt even go up to 0. I hardly ever run my car hard, so i just noticed that my gauge doesnt go up all the way, so the gas might not have anything to do with it. Any help will be much appreciated.

 

get an aftermarket boost gauge, stock one aint that good

 

There's a built-in self check every time you key in the ignition to the "ON" position prior to cranking.

Does the needle go to "0" when you first click on "ON"?
If yes, the boost gauge/sensor is probably okay - you have a boost leak somewhere or your turbo is bad.

If it doesn't hit "0", the boost sensor or wiring is bad.


-Ted

 

lucky we only have 91 octane here in cali and very expensive

 

The dash boost gauge is problematic.
I bought a cheap $15 Sunpro just until the Autometer shipped.
It worked so good I canceled the expensive one.


Here is the test gauge I verified with.