Hopefully someone can confirm my suspicions...

My sister-in-law has a 1999 Buick Century with the 3100. She'* having an intermitten problem with it starting, then instantly stalling. It did it several times this past week on her way from WY to MI (1000 miles or so). I drove it for a few hunderd miles and it never acted up on me. And, it never bogged on me at all (even at WOT from a dead stop).

So, tonight I scanned it for codes and found none. I then checked the fuel pressure. Here'* what'* odd. According to the Chilton'* it should have 48-55 lbs. with just the key on. It currently reads 41 lbs. with the key on. On start up we're only getting ~40 lbs. If I race the engine at the TB, it jumps up 5 lbs, then down 7 lbs. to sit at ~38 lbs. The book calls for a 3-10 lb. variance once the car is started, so 38-45 on the low side. I'm thinking it'* the fuel pump. Can anyone confirm? The really odd thing is that when I went to move the car in teh driveway I started it up and it stumbled to stay running. I restarted it and feathered the gas to keep it running. As soon as I let off it stalled. Restarted it normally and it ran great. I rescanned for codes and still nothing. Rechecked pressures and they were the same as my first investigation. I don't think it'* ignition related, but I could be wrong...

I located the access panel in the trunk. Should be an easy swap, but list price on the pump is $240. I want to confirm my "guess" before she spends all that money. Oh ya, the fuel filter is only 3,000 miles old. It could be bad, but my guess would be that it'* not.

Thoughts?

Fuel Filter?

The fuel pressure regulator could also be at fault correct? thats a cheaper place to start than the pump itself.

yup the regulator could be at fault but most likely your fuel filter is clogged

I just swapped out the pump and filter. The filter was not clogged, as I expected. The pump seemed to be faulty. I'm now getting the proper pressures....just in time for her to drive back to WY in a few hours.

I also noticed the car had better acceleration out of the hole with the new pump...