Errors 24, 31, 42 & 51
 

My engine keeps dying when the engine is cold. After 10 minutes of starting and restarting and the engine is warm everything runs fine. I received these four error codes (24, 31, 42, and 51) on my 91 supra turbo. I replaced the air flow sensor and Throttle position sensor but everything is still not running too well. My speedometer is out too but don't know what part to replace. Any help is greatly appreciate. The more details the better.