Mystery Please Help

2001 Bonneville

Car turns over but will not stay running.

This only occurs at random.

Already replaced air flow sensor, fuel filter, fuel pump, and fuel line.

Any advice?

You seem to have decided the problem is fuel-related. Are you sure the ignition system is not the problem?

I know nothing about cars!!!
The only way the car stays running is if you are on the gas.
When the mechanic runs diagnostic test, nothing comes up.
No lights, no check engine, no security light.
What would indicate ignition?

If you mean the engine starts, but shuts down a few seconds later, it might be because of a defective ignition module. Is that what happens?


If you’re able to keep the engine running by applying the gas, this points to a defective Idle Air Control valve.

This component is mounted on the throttle body and it’s function is to allow the engine to idle anytime the accelerator is released. These IAC valves can become lazy as they get old where they fail to go to the proper position for the idle condition. When this happens, the only way to prevent the engine from stalling is to apply the gas pedal.


This is exactly what my tow truck driver said.
So how do I convey this to my mechanic without sounding like an idiot.

Also, since the problem hasn’t been fixed, am I obligated to pay for them to fix it again?

Go to your mechanic and say, “Hey (name here), do you think there may be a problem with the Idle Air Control valve? Because when the problem occurs, the only way to prevent the engine from stalling is if I give some gas.”


That is exactly what they found wrong!!!