My 1987 Allante (137,800 miles) ran really well until recently. After driving about 5 miles in traffic it stalled at a stoplight. It restarted but stalled again, and again and again, etc. I drove into a parking lot. After several minutes it began to run well enough to try to make it back home. On the way it again stalled. I had it towed to my usual garage. They pressure tested the fuel pump and replaced the fuel filter. It also needed a starter; but it continued to stall so they replaced the distributor.
After repeated test drives it continued to stall (intermittently) so the shop returned the car and said they were at a loss as to what to do. I drove the car 15 miles on the expressway and another 9-10 on surface streets. It ran great but again began to stall and would not 'turn over' and keep running. After 10 minutes, it started and I drove it the 20+ milesback home without incident.
Took it to a 2nd garage that specializes in Cadillacs but it wouldn't stall after 2 days of trying. So I picked it up and drove 12 miles back home on surface streets. It ran flawlessly until I got home and let it idle in the driveway for about 5 minutes. The rpms went from 800 to 1000, back to 700 back to 1000 and eventually stalled. A while later it started and
idled unflinchingly for 7-8 minutes. I then drove it a few miles, returned, allowed it to idle until it stalled.
I drive the car about 7000 miles per year. One year ago I had the 2nd garage replace the cam sensor and the isc motor. It ran well until this recent bout of stalling. No, actually it has stalled previously when I have slowed to turn a corner or when approaching a red light. But I could always put it in neutral, crank the engine and continue driving without
I can't tell if when it begins to stall the isc motor starts searching for the right rpm or, if the isc motor is out of whack and causing it to stall. Runs great, then begins to stall. I always use premium gas and keep the car serviced. Both garages are honest and very experienced. Any advice will be much appreciated.