90 mustang help!

[Rempdawg]

I got a 90 mustang 5.0 bored 30 over, forged internals, Stock heads and Cobra intake, Stock injectors, CAI, Headers, O/R H pipe with slp cat-back. well my question is whats wrong with my car. If I start it when the motors cool, then it starts right up, idles around 700 rpms, and drives perfect until the motor gets about 190 degrees, then it misfires, check engine light pops on and off, not long enough for me to put a scanner on it and if I come to a stop it dies, also the volt gauge is always a 13.8-14.4 when I start it when its cool but when its warm its around 10. But every single time I start it, it fires right up. when its warm it fires up and the rpms go from 2000 to 700 until it ends up dying. Also when I turn my heater on, the volt gauge drops. please help me. thank you

 

[1991notchbackLX]

Do you have a voltmeter to see how many volts your alternator is putting out? It sounds like it's shot, honestly.

 

[Rempdawg]

I do have a voltmeter, and when I am full throttle check engine light flashes and it smells like its running pretty rich.

 

[betke76]

check codes then report back. so we have some kinda starting point

 

[darthcual]

Check the vac line that goes to the fuel pressure regulator. If theirs fuel in it, it needs to be replaced. After warm up also could be the o2 sensors, act sensor, ect sensor.

 

[1991notchbackLX]

The alternator should not be putting out 10V at any time. Flashing CEL and dumping fuel sounds like the car is going into limp mode as well.

 

[Rempdawg]

Im gonna get the codes checked here after a little bit, then ill let u know. thanks guys

 

[Rempdawg]

I also just replaced the act senser and the ect senser. so I hope its not them.