I have a 2001 oldmobile alero 4 clynider and it has been acting up. It dosent want tto start up at times and when it does only for a few seconds or it will run just fine for a while then act up all of a sudden. i changed the fuel pump , did tune up, put throttle pistion sensor all new and nothing. Help me pleas i really need my car to work it my only transportation.

SOURCE: 2001 Olds Alero Wouldn't Start

I had a problem similar recently, just wouldn't stay on. Found out that there is a flaw with the sensors on those cars for the ignition "talking" to the computer's Passlock II thing. The car thinks it's getting stolen so it engages the anti-theft which turns off the fuel injection. You just have to reset the Passlock. Turn the key to the first On position where you have radio but no windows, leave it for 10 minutes until the little Security light turns off. Turn off the key then start it.
Don't know if it was your problem, but just so you know, the sensor part will eventually start failing with this car.

SOURCE: 99 olds alero 2.4

I'm sure you have installed a fuel pressure gauge and monitored the fuel pressure while the problem is occurring?Another diagnostic tool which is easy to do,is while the problem is occurring,unplug one sensor at a time beginning with the Mass Air Flow first,.if it uses one.Many times,not always,depending on the sensor,if the sensor is taken out of the picture as far as what the PCM is seeing,like unplugging the MAF,the PCM will substitute the missing sensor output with a generic value that will allow the engine to at least run,and if unplugging for example the MAF,the engine idle speed returns to normal,you know you're onto the problem.You didn't mention if the engine ran ok other than the idle problem.As far as checking for vacuum leaks,i use something like brake cleaner or WD 40,more of a liquid,and it does sound like a vacuum leak.Plastic intake manifolds do develop nearly invisible cracks that open up more with heat.Revsisit the possibility.And as for the PCM,it is possible,but more likely a mechanical problem.Lastly,remove an O2 sensor or two before the catalytic convertor,run the engine and see if anything changes.Cheap way to verify the catalytic convertor is flowing and not restricting engine airflow,as i have seen bad cats cause misfire codes and strange problems.Good luck.

SOURCE: Car is cranking over, but

try spark plugs, plug wires, distributer and coil.

SOURCE: 2003 OLDS ALERO WONT START

find the buzzing noise...likely its the fuel pump relay.

SOURCE: 2001 alero ran out of gas now it wont start after

You have are in the line you have to prime the line to get pressure thru