Im sure lots of had this prob. I got a 87 TII and the factory boost gauge wont make up its mind. Some times it reads right then some time it reads like just above zero and who knows out of knowehere it reads full again. I have a aftermarket gauge and it always shows 5.5 psi at full boost even when the stocker shows 0 when i should be at full boost.

How do you fix the damn thing?

Lynx

 

stock gauge is not very accurate, so i would say forget it and just install an aftermarket one
save u some trouble and also a safety mod also

 

I'd run a meter to the wire on the ECU that receives the signal from the boost sensor and make sure that the ECU is receiving a signal from the boost sensor. The ECU needs this signal to tell how much load is on the engine so the ECU can determine how much fuel the engine needs. Look at http://www.iluvmyrx7.com in section 4B under Control Unit to determine which wire at the ECU is the boost sensor wire. There is also a test procedure for the boost sensor in section 4B. Might also check and see if the ground wire is really, really good at the boost sensor. If the engine is working its behind off but the ECU just sees a loafing engine, the fuel delivered will be lean. Lean equals ping. Ping equals broken apex seals. Made the last two remarks up out of whole cloth. EDIT: I think maybe you should ring the wires from the boost sensor to the ECU. Ring from end to end a while doing so shake the wiring. Same from the ECU to the plug to the gauge.