I have an '89 5.0 5-speed Mustang with 124K miles on it. Under full throttle acceleration in first gear the engine dies out somewhere above
3,500 RPM. It almost feels like a rev limiter, valve float or fuel starvation. However, if I cruise on up to 5,000 RPM at a bit more leisurely pace, it runs fine. It's only under full throttle and only in first gear that I've had the problem. What's up?Some additional background; 3.73 gears, full aftermarket exhaust, K&N fender mounted cold air kit, 1.7 rockers, underdrive pulleys. All air and fuel metering components are stock and original except for an aftermarket fuel pressure regulator. TPS setting was verified today at .997 volts. The long block is stock and original except for the 1.7 rockers. I'm still running the original fuel pump although the fuel filter has been replaced.
Thanks! Dave