Cadillac Repair: it keeps cutting off, cadillac deville, 2001 cadillac deville

Question
hi, I have a 2001 cadillac deville and it runs smooth.  I mean smoother than a baby's bottom sliding on ice!  But after a few miles it will cut off as if its out of gas.  and this usually happens after you first start the car up and ride fora minute.  i would be on at least a half a tank and it will just stop.  But here's the wierd thing about it,  it'll stay off for a long period of time.  and when you try to crank it back up it will sound like im out of gas.  so i let sit for about 15-20 minutes and then everything is back to normal.  why does it do this?

Answer
Hi Ryan, What you are experrianceing is usually a symptom of when a sensor for the engine/powertrain computor or ECM/PCM for short is going bad. Hot and cold can affect those parts and cause them to fail without notice. It could be a soldier joint that opens up in a module or the sensor cracked internally and is putting stress on the internal wires. When cold the wires are together and as the plastic heats up it expands and pulls the wires apart. The tough part is haveing test equipment hooked up to the car and catch it when it happens. Fortuneately for you the problem can be duplicated easily and stay acting up long enough to determine what is causeing the problem. What I would suggest is run the engine in the driveway until it quits, then perform the following tests.

     Since you feel that it is fuel related turn off the key and remove the gas cap. Have someone with good hearing listen at the filler opening while the other person turns the key so the dash lights up but doesn't turn the starter. If you don't hear anything try the test several times makeing sure to turn the key off for at least 5 seconds before turning it on again and if still nothing then it is fuel related like the pump, relay or possably the PCM.

      If you hear the fuel pump for 2 seconds and then stop  then you will need to test for spark. An easy test would be to test for spark at the coils with a tester that looks like a sparkplug with an alagator clip or some companies have a tester where you remove the plug wire and install the tester between the coil terminal and wire. If there isn't any spark it could be due to a bad ignition module that is located beneith the coils or more likely the 2 crankshaft sensors have gone bad. Cadillac did have a campaign on the 2000 Deville and maybe it carried over to the '01. A call to the dealer service department would answer that question. Otherwise if your car has around 100,000 miles or more with the original crankshaft sensors I would suggest replaceing them and your problem could be fixed. They are located in an ocward spot on the radiator side of the engine behind the exhaust pipe. There you will see the 2 crankshaft sensors held on by a 10mm head bolt once you safely support the car high enough on jackstands to slide underneith.

    Hope that helps and let me know if you have anymore questions. Bill