I have a 1994 GT (5.0) when it's cold it runs fine but after it warms ups the idle is pulsating up and down then shuts off I have replaced fuel pump/ filter and the IAC control (Idle air control motor)new
plugs/cap/rotor button No engine codes show-up to suggest any electrical problem.HELP
                  Junkman  

Have you checked for vaccum leaks, if not its to check. take a can of carb cleaner with the car running when it starts to surge start sparying the carb cleaner where ever you have vacuum lines if there is a leak it should start to smooth out the direction of the spary can help you locate the leak. good luck hope this helps  

I fixed the idle problem (TPS) now i have a code saying I  have problem with fuel pump secondary circuit failure battery to control module can't find any thing wrong I hope it's not the module can you help.  

I fixed the fuel pump problem also, it was the ccrm. better know as the constant control relay module.located
in front of the radiator reservoir if anyone ask.The mod. contains the pcm relay/fuel pump relay/eec relay all mounted on circuit board non repairable !