1991 regal shuts down after 15 mins of driving/warmup.

okay. my 91 has been running great since about 91, but now it started something odd. i had my oil changed to a full synthetic and two days later, it shut down on the highway. the radio still works, the a/c runs fine when the engine is on, and it still starts like a champ. after it warms up, the engine just stops turning, taking my a/c and power steering and power braking along with it.

my radio stays on, there are no wierd noises when it shuts down either. could something be getting choked out? i changed my oil back to what it was before the issue, and i replaced the fuel filter as well.

Welcome to AF. How do you get it started again, have you checked for spark when this happens, how about fuel pressure at the rail, not much info to work with here, none of the basic checks have been performed. The oil issue is irrelevant to the stalling.

BTW, the synthetic oil had nothing to do with the engine stalling. It is simply a coincidence that this happened after the oil change (unless you forgot to put the filter on, or the drain plug in)!

check fuel pressure at time it stalls if no pressure its the pump if there is pressure check for injector pulse and will go from there