My 2002 Cadillac (135,000 miles) stalls about once per week at stoplight or stopsigns. There is no stumbling or stuttering, it just quits.It has been doing this for about 2 months. But here is the catch… It ONLY does it when the engine is warm (running for 2-5 minutes). It never stalls after 5 minutes and never stalls when the engine is cold.
When it does stall, it take about 30 sec to a min to restart and it seems to help if I press on the gas a little bit when starting. I suspect… Idle control valve, egr valve. I was wondering about vacuum leaks but I doubt it since it is only stalling at stop lights. Also, once it has stalled, it won’t stall again until a few days later. Never stalled twice on a row.
No matter what things I look at I think it has something to do with the units on the throttle body, or a temperature sensor that is flakey. Oh… .one other thing… when the engine is warm, it seems to idle slightly rough (not bad at all, but seems to barely notice a slight stumbling) I know it isn’t sparkplugs because I has new ones put in. Many Thanks !