stall issue

Replaced fuel pump in '99 MC 3.1 good pressure now but runs for a few seconds then dies... any thoughts ?

Anyone ?

Why did you replace the fuel pump in the first place?

Sounds more like a security problem......if fuel pressure is ok, and it starts and then dies, get a can of carb cleaner.....have someone crank the car while you spray carb cleaner into the throttle body....if it starts and runs as long as you spray, and dies when you stop spraying, then the injectors are not firing and it's a possible security problem....usual fix is a PassLock sensor...will usually set a B2958 or B2960....most scanners and code readers can't read "B" codes.....

fuel pump had lower than needed pressure but I pulled the icm and had it tested. It failed test so replaced it and all is back to normal with the exception of a small vacuum leak yet to be determined . Thx .