sts cold start problem

I having problem with car not starting when it sits overnite, i have replace the fuel pressure regulator and the air mass sensor, and the 02's, when the car is worm it rund fine a little slow in the acelatrion. the milage has drop and the engine codes said it is running lean. the car is a 97 sts with only 57,000 miles.

How old is the fuel filter, what is the fuel pressure, what codes did you have, why the maf?

The Fuel Filter Was Replace The Same Time The Fuel Pressure Reg. Was Replace, The Codes Are Left, And Right Bank 02 Lean And Po171

Again look at fuel pressure under driving conditions, the engine is running lean, as you know. Also check the baro readings on a scanner and make sure it coincides with your area. Make sure you have no vacuum leaks and no air getting into the intake behind the maf ducting.

Again look at fuel pressure under driving conditions, the engine is running lean, as you know. Also check the baro readings on a scanner and make sure it coincides with your area. Make sure you have no vacuum leaks and no air getting into the intake behind the maf ducting.


I CHECK THE FUEL PRESSURE AND IT WAS AT 20 PSI WHEN RUNNING SO IT LOOKS AS IF THE FUEL PUMP HAS TO BE REPLACE, ANY TRICKS ON CHANGEING THE PUMP IN THE TANK????

Tank has to come out no tricks, just need a lift and carefulf with tank, run it low as possible, not a job to do in a dwy.