2000 Buick Regal stalls while driving

My 2000 Buick Regal has died multiple times in the last week as I was driving. The engine quits in as little as five minutes, but might take longer, and always happens as I am decelerating (foot off the accelerator, applying brake). Cranking causes the engine to fire, but not enough to keep running. It might take up to twenty tries to get it running again.

En route to my mechanic, driving slowly and gently, the car would not stall. The mechanic road tested the car, and made it stall.

Initially, error codes P0300, P0463, P1096, P0103 and P0128 were read. The older battery was replaced and the positive cable serviced. The ECM was reprogrammed (cost: $100!), and the Regal ran well for a day. Shortly thereafter, it began dying as before, and was returned to the shop.

Since then, it has been in his shop for four days, engine idling with test equipment attached. When it dies, it starts up immediately, and no error codes are present. He is at a loss.

He replaced the crankshaft sensor (at my urging), and it looked like the problem was solved. Not so! It only took a few miles for the problem to happen again.

The odometer light has not worked for several weeks, but I doubt if this is connected.

Anyone have any idea as to what might cause this?

The replacement of the battery, the “servicing of the positive battery cable”, and flashing of the engine computer may have been coincidental to a few miles of trouble free miles; or, there may be a real cause and effect.
How was the positive battery cable “serviced”? A battery cable is usually “serviced” by: disconnecting the cable from the battery, using a file, or wire brush, or sandpaper to remove the corrosion from the cable terminal part which contacts the battery post. Then, petrolatum jelly is smeared on the terminal and post, and the terminal re-connected.
The above cleaning technique should be performed (even, again, if it was done).
Some of the diagnostic trouble codes, P0103, P0128, P0463, seem to be caused by shorts. That’s my first impression, based only on how the codes read. Your mechanic could check out one of the circuit and see if something is wrong with the wires (shorts, opens).
Did the other Web site have any interesting ideas? http://www.buickforums.com/forums/showthread.php?p=42673

The “servicing” was done as you suggested: removal, wire brushing, etc. There are no error codes presently showing. The car runs fine until it stops, but restarts right away. I’ve questioned the key with a chip, but mechanics say it’s not the problem.
Other web forums suggested the Crank Sensor, which did not help. Current suggestions point to fuel pump or filter. It amounts to my “trying” each suggestion, finding it does not help, and getting more “try this” suggestions. In the absence of error codes, it may be a miracle if my mechanic stumbles into the solution. Last thing I want to do is . . . take the car to Buick! I don’t make enough money to afford going back to a Dealer - actually, since I was laid off 2 weeks ago, I don’t know how much more of this problem I can afford.

There is a tool to help mechanics find the major system the fault lies in; but, no ones seems to have it, or use it. Just one misdiagnosed fuel pump, or misdiagnosed MAF sensor would pay for the tool. It’s ironic that people, including mechanics, are willing to pay for parts, but, aren’t willing to pay for diagnostics, or diagnostic tools. I suppose some of the reason is that parts are tangible, whereas, diagnostics aren’t as tangible. Can you hold a diagnostic in your hand?
The tool is called What Quits First. It will tell the mechanic if 1. fuel quit, or 2. spark quit, or 3. if the fuel injection quit and caused the engine to stall. Knowing which major system to look at, and which not to look at, saves a lot of work checking suspects in other systems. This saves the mechanic time (and hair) and the customer money. The price of the tool is easily amortised over a small number of repaired vehicles. http://www.lenehanresearch.com

By taking care of the problems revealed by the DTCs (Diagnostic Trouble Codes), the cause of the intermittent stalls may be revealed, or (incidentally) fixed. Did you notice the word “Diagnostic” in DTC? It’s meaningful. The DTC codes are to help the repairer find the cause of the malfunction.
P0103 Mass, or volume, of air flow [sensor circuit shows] high input.
P0128 Coolant thermostat [engine coolant temperature sensor] (coolant temperature [indication] is below the thermostat regulating temperature [limit?]).
P0300 Random misfire [has been] detected.
P0463 Fuel level sensor A circuit [has] high input [voltage].
P1096 This code is probably an error.

For code P0103, the MAF (Mass Air Flow) sensor should be checked (voltages and ohms).
For Code 0128, check the ohms and voltages of the engine coolant temperature sensor.
For P0463, check the fuel level sensor circuits for high voltages (possibly a hot short, wire to wire).
For P0300, the misfires may be fixed when the other sensors are fixed.
The instructions for doing the voltage and ohms checks on the sensors are in the Haynes or Chilton’s repair manuals. Use a digital multimeter, and check the wiring and the connectors as well as checking the sensors.
“The engine stalls when I press the brake pedal” [Paraphrased]. Check for a leaking/ruptured brake booster by pinching closed the brake booster vacuum hose, as the engine is running. Then, pinch the brake booster vacuum hose closed while depressing the brake pedal (engine running). If the engine is affected, by pinching the vacuum hose, the brake booster has a leak.

Fuel pressure is fine, and the slow speed idle sensor was replaced. Car runs fine at freeway speeds, and has run nicely for 2 days. Last night it simply stalled and would not restart. Ten minutes later it started up, and I was able to drive it home. So - it’s not the MAF, the crank sensor, the low-speed idle sensor, the ignition switch connections are tight, and the battery and cables are okay.
The Buick Regal still stalls unpredictably, and I cannot afford another car. Where do I go from here? (Dont’ say Junk Yard, please)
Incidentally, the odometer light is out and the fuel gauge is flakey (it sometime reads and other times does not)

My first thoughts about the cause of the trouble is the fuel system or the MAF sensor. You stated that the engine tries to restart but can’t keep going. This to me means either a lack of fuel or proper fuel mixture.

The ignition system will cause sudden stalling and failure to start. The next time it stalls and doesn’t start or restart, use this inexpensive device to check for spark: http://cgi.ebay.com/ebaymotors/Dont-kick-it-get-a-Cricket-ignition-spark-tester_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1171Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a0Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem130299412295QQitemZ130299412295QQptZMotorsQ5fAutomotiveQ5fTools Let us know the results.