I have this weird issue with my prosport mechanical boost gauge. After my runs I pull in and let the car idle. I eventually shut the car off and when I start it back up I notice that my boost gauge is sits at 0 instead of the regular 19 in hg. where it should be. It will sit at the 0 mark for a few minutes, almost as if the needle is stuck, but eventually drops down. THIS ONLY HAPPENS AT THE TRACK, btw. Could this be happening due to a boost leak somewhere in the system? I did a boost leak test and I do have injector seals leaking at 25 psi, although I am tuned up to and only boost to 23 psi. I have had prosport warranty and were great enough to send me a new gauge with no difference. I have switched from the vacuum lines they supplied to some vacuum lines from STM, and still only slight improvement.
I have secured the gauge to keep it from vibrating and even rotated the gauge so the needle could sit horizontal at 0 to see if it makes it better. I just dont know if its an inherent design with the mechanical gauges or that this is maybe more of a 'street' gauge, where its just not really meant for track abuse. My next step is probably just get an autometer gauge, I have tracked plenty with those and never had any issues.

 

Happens with my electrical Defi boost gauge if I restart when the motor is hot (dyno/track). Sits at 0 then comes back to life after a few minutes. Thought the sender unit under the hood was getting to hot, but hearing about the same issue with a mechanical gauge is interesting.

 

Interesting. Thanks for that info. I wonder then if it is something within the vehicles system???