96 Saturn SL2 - Sometimes Car Won't Start. Why?

I have a 96 Saturn Sl2 - stick shift. Most times, the car starts with no problems. At odd intervals however, the car won’t start when I turn the key.



The mechanics at the local dealership can’t figure out why because the car always starts for them.



When the car won’t start (has happened six times over the past four months), I will hear a humming sound from the fuel pump and then nothing happens. The engine does not turnover. There is no clicking sound either. But, the radio and lights work fine.



The problem occurs when I’ve driven the car for a mile or less, particularly when I’m running errands. (Last Saturday, it occurred when I was leaving the gym.) Three times, if I let the car sit for a while, it starts. (Last Saturday, it started right when the tow truck driver showed up - without a jump).



Twice, it started with the help of jumper cables. Once, it wouldn’t start without jumper cables, but it did finally start when the tow truck driver popped the clutch.



The mechanics have looked the car twice now and both times they are completely stumped. They can’t replicate the problem and they can’t figure out anything wrong.



Any ideas?



Thanks in advance.

Just checking to see if anybody has ideas. I’m having the shop order a new switch for the clutch, but I have no idea if this is right solution or not.

You have the wrong shop, and the wrong mechanics! This problem is mechanics 101. The solution involves a qualified mechanic, an electrical test multimeter, a wirig diagram, and willingness to go a-hunting.

two things to notice/look for.

when this happens note if the radio and dash lights (you know the eml, cel, abs, and seatbelt warning lights)

if they don’t come on then the problem is in the ignition switch.

the other issue is (and it is REALLY simple)

when you push in the clutch it has an interlock switch. if you don’t push the clutch ALL the way in, the ignition won’t start the car. a common (but overlooked) problem is that if the carpet or floor mat gets caught up under the clutch pedal it can prevent the ignition from starting th engine.

make sure the floor mat/carpet is not sliding up, under the clutch pedal.

really simple, but it could be important.

Update:

I had the clutch switch replaced two days ago, after the mechanics could not replicate the problem, on a hunch that that could be the cause. This morning, after the car was sitting in the garage last night (it was below freezing last night), it would not start again.

Here is everything that I noticed:
Humming sound from the fuel pump went on a for a few seconds before ending with a click
Dashboard lights came on when I turned the key
Interior lights came on when I opened the door, a sign that the battery is working
Engine would not turn over

The fuel pump makes the humming sound regardless of whether the clutch is engaged or not. Thoughts on what the problem could be? A dead spot in the starter?

One thing to have checked out is the positive battery cable. The battery cables on your vehicle are the side mount type to the battery. It’s under the red rubber cover of the positive battery terminal where corrosion can form. This corrosion can cause a voltage drop to the power distribution center. When this happens, enough voltage can allow some circuits to work properly, but when another circuit is added, such as the starting circuit, the voltage drop can be enough where this circuit won’t operate.

This is a known problem on GM vehicles with side mount battery terminals. And since the vehicle is twelve years old, it might be worth checking out.

Tester