Shuttering, stall, then fine!

I have a 2002 mercury sable- 65,000 miles- just bought it 3 months ago. 6 weeks after buying it- my daughter is backing out of her driveway, the car begins massive “shuttering” and stalls. Won’t start again for 24 hours. Not certain if this occurred before this incident, but then at LOOONG red lights in Cleveland, or stop and go traffic, sometimes it would sputter, like it was going to stall. LAst Friday, it did stall in traffic, but she was able to start is right up, drive for hours with no problem. I drove it Monday morning, and at the third regular stop light it gave once “sputter”, the rpm spiked and came back down- light turned, I continued- no problem. Drive all around , no problem. Wednesday, drive it 7 miles, park, tease it by idling in drive 5 minutes, then reverse and idle, and back and forth a few times- no problem. Shut it off. 45 minutes get back in, start it-very rough- back out- seems like it is bucking-not getting gas- but I back out, put it in drive- drive about 100 yards and it stalls- and will not start. Someone told me I was blowing lots of white smoke. Toe truck comes- gets it started abiout one minute and it stalls. Tow it 5 miles, get off truck, he astarts it, and it starts smooth as can be. Next day, my mechanic tries to get it to sputter or stall- nothing- works like a charm. He gets a computer code p0191. Lifts the hood and happens to find the red lead off the battery very loose. tightens it. COULD that be the problem, or is it a fuel problem or a computer glitch? Help!

Hard to say. I’d drive it around awhile and see if tightening the battery clamp fixed it. It could be that the loose wire was causing insufficient power to get to the fuel pump, which lowered the fuel pressure on the rail, and threw the code.

The other alternative is that you have something actually wrong, like a dying fuel pump or a clogged fuel filter, and that’s throwing the code while the battery cable being loose is a separate issue. If it’s that, then I’d go over the car pretty carefully because it’s likely the people that had the car before your daughter didn’t maintain it properly.

It is certainly possible that a loose battery connection could do something like this, though I’d actually expect to see more than just one code. Did your mechanic happen to look at all at the fuel rail pressure sensor? (P0191 Fuel Rail Pressure Sensor Circuit Range/Performance). Did the mechanic clear the code?

Just drive for now. If it continues to happen then, yes, someone needs to troubleshoot the fuel delivery system starting at the fuel rail pressure sensor. I’m actually somewhat surprised that you are posting after having a mechanic look at it and pull this code. Did this mechanic not explain this to you or did he just shrug at you or something? If so, next time take it to somebody else.

If your check engine light comes (back?) on don’t ignore it. Have it scanned for codes again - many auto parts chain stores will do this for free. Write down the exact codes and post them (as you did above).

Thanks for your comments. I brought it to a ford dealer. The message on my phone machine is that I need a fuel filter, end fuel pump (is that the one in the gas tank?) and a computer update. He quoted $1000 cost. Does this and the price sound right?

Ended up being the fuel pump. Thanks for your responses