Car Talk: Truck's fruit fly infestation is driving the owner buggy

Q: I am at my wits' end. I have fruit flies in the cabin of my 2012 GMC Sierra 1500. I never ever eat fruit to begin with, and I never allow anyone else to eat it in my truck. I have fogged the interior with enough Raid to cause genetic mutations in my grandchildren, to no avail. The bugs return within a week. Short of using a flame thrower, I can't imagine what else to do.

Upon further consideration, the flame thrower gambit is out. I don't want to escalate the tensions. But any other advice would help me.

A: First of all, you should eat fruit. Fruit is part of a healthy diet, and we'd like you to outlive the fruit flies.

You've already eliminated any visible sources of food for them, and you've even resorted to chemical warfare. So what's going on?

Honestly, I don't know. I'm a mechanic, not an entomologist. But I'm guessing there's a source of food for them somewhere in your truck that you haven't found. Are you sure your kids aren't sneaking in a tidbit or two of fruit when they sit in the back where you can't see them? Or, it's possible someone dropped something onto the carpet and then it got mashed by a shoe. So a thorough upholstery and carpet cleaning is a good place to start.

My other guess is that there's some organic material that's dropping onto the hood of your car and entering the ventilation system through the cowl (the fresh air vents where your windshield meets the hood). If something from a fruit tree fell through the cowl, it could attract fruit flies there. And from there, the flies could make their way through the ventilation system to the cabin.

Look at what trees you're parking under. And once you're sure you're not continually replenishing their food supply from above, nuke the cowl area with the fan on full blast. If that doesn't work, you'll need to get into the HVAC system to clean it out. We hope it doesn't come to that because that stuff is tucked up under the dashboard, and not easy to get to.

Q: I have a 1989 Lincoln Town Car that sometimes cuts out when I give it very little gas, like when I'm inching my way along a drive-through line. What could cause this? I've replaced the spark plugs, wires, cap, fuel filters and fuel pump.

A: This thing is so old that it's carbureted. And I think that's where the problem lies. A carburetor has a little pump called the accelerator pump that squirts in a little extra gasoline when you first step on the gas pedal. Once the gasoline is flowing, the suction created by the pistons draws all the fuel it needs to respond to your acceleration requests. But in that first instant, if the engine doesn't get that extra shot of gas, it'll stall.

The good news is that accelerator pumps are cheap. You probably can find one online for about $10. The bad news is that you probably didn't need any of that other stuff you bought and installed: the wires, plugs, fuel pump, etc.

If I remember correctly, on this car, the accelerator pump sits on the front of the carburetor and attaches with four simple screws. It's a job a DIYer can tackle. Otherwise, look for a mechanic who remembers how a carburetor works. If you pay him for an hour's labor, he might also blow out the pump's fuel passage with some brain-cell-killing carburetor cleaner. And that's not a bad idea at this point.