I have a 2000 Alero with the 3.4L engine. On the way to work I noticed I began to slow down and the gas pedal was unresponsive. The tach went to 0 RPM. I eventually coasted to a stop. The motor would turn over no problem, and when I turned the key off and back on, I could hear the fuel pump pressure up, but it would not start. I found that if I turned the ignition all the way off, as if to remove the key, and tried to start the car the engine did start and I could travel another mile and the same scenario would develop all over again. Each time, when I turned the ignition all the way off and tried to start the car it would run. If I did not turn the ignition all the way off, the car would not start even though it turned over normally. Is this the 24X sensor problem? I replaced my fuel filter a month ago for this same thing.

Thanks

It sure sounds like it. Also, there is a 3X crank sensor on the side of the block but it very seldom, if any, goes bad. It is not that bad of a DIY job to change the main CKPS out.

Thanks bnaylor for the reply. BTW, I stopped by the parts store on the way home this morning to check on price and availability of the 24X cam shaft sensor. The guy behind the counter took exception to the fact that I got the idea that the 24X sensor was the possible problem off the forum here. He tried talking me out of ordering the part, stating he had never sold one out of that location, and had to special order it from his warehouse. Sure enough, I checked a different parts store and he had never sold one either. If I didn't know better I would suspect the gas pump, though the only reason is the way the car acts. Is there a way to prove what is wrong when it is so intermittant?

Thanks,

Mike

Thanks bnaylor for the reply. BTW, I stopped by the parts store on the way home this morning to check on price and availability of the 24X cam shaft sensor. The guy behind the counter took exception to the fact that I got the idea that the 24X sensor was the possible problem off the forum here. He tried talking me out of ordering the part, stating he had never sold one out of that location, and had to special order it from his warehouse. Sure enough, I checked a different parts store and he had never sold one either. If I didn't know better I would suspect the gas pump, though the only reason is the way the car acts. Is there a way to prove what is wrong when it is so intermittant?

Thanks,

Mike

If you're referring to the camshaft position sensor, I've never heard of one going bad on the 3.4L V6. The sensor that does go bad is the crank position sensor (CKPS) which is located behind the harmonic balancer and pulley on the crankshaft. Although not common, it is a known problem.

However, I would not rule out fuel supply as a problem first. On the back fuel injector rail, passenger side is a Schrader valve where you can check fuel pressure with an automotive fuel pressure gauge. The Alero fuel pump puts out pretty high pressure in the fuel pump prime position and while engine is running. There is a fuel pressue regulator located on the front fuel injector rail, driver's side that you will need to remove the vacuum line to it when running fuel pressure tests. A good fuel pump will put out around 59 psi and higher with the vacuum line disconnected. Also, a defective fuel pressure regulator can give similar symptoms.

The gauge can be left hooked up while you run the car. I've taped the gauge to the driver's side wiper just for testing purposes and so you can see it while driving. Good luck!

Update: I installed the switch to turn off the "Passlock" feature on my car, only to have the same problem develop 15 miles away. The car died. After I had the car towed home for $58.50, I quickly hooked up the fuel pressure gauge and discovered I had no fuel pressure, even though I could hear the pump running every time I turned the key to the "On" position. I even bled the air out and checked the gauge several times, each time the reading was 0. So, I broke down and replaced the pump and the plug connector to the fuel pump, (recommended by the parts house). My car is running now and the during the small trips we have taken there has been no further problem.

Thanks,

Mikehave taken

Update: I installed the switch to turn off the "Passlock" feature on my car, only to have the same problem develop 15 miles away. The car died. After I had the car towed home for $58.50, I quickly hooked up the fuel pressure gauge and discovered I had no fuel pressure, even though I could hear the pump running every time I turned the key to the "On" position. I even bled the air out and checked the gauge several times, each time the reading was 0. So, I broke down and replaced the pump and the plug connector to the fuel pump, (recommended by the parts house). My car is running now and the during the small trips we have taken there has been no further problem.

Thanks,

Mikehave taken

That is good news Mike. Good job! Now your Alero is "esta bien"...lol. :lol: