Drive It Forever
Q. I have a 1996 Plymouth Breeze, and since I had the fuel pump replaced - with a used pump - the car won't start normally. When I start my car, it cranks over like it's going to start, but it doesn't. I have to do that two or three times to get it to start. If I start the car, turn it off, and start it right back up, it cranks over on the first try, the way it should.
A. I'll make an educated guess that the fuel system is losing its prime, and you need to cycle the key a couple of times to have the pump run fuel up the fuel lines into the injectors.
But it may not be the pump's fault. There's a check valve in the pump to keep the fuel from running back into the tank. That valve may be bad. A small leak in the fuel-pressure regulator could produce the same effect. Or one or more of the fuel injectors may be slowly leaking fuel into the intake manifold.
You're right to think that the pump may be to blame, given that the problem surfaced so soon after it was replaced. But it could also be that some dirt was introduced into the system when the new pump was installed. It takes only a small piece of gunk to settle under a valve seat or in the pintle of a fuel injector to jam it open.
Here's a workaround: Instead of cranking the starter incessantly and prematurely wearing out it and your battery, simply cycle the ignition key on for a few seconds before hitting the starter. The pump will run for a few seconds, until the engine-management computer realizes that the crankshaft isn't turning and shuts off the pump. Repeat this key-on, key-off cycle two or three times to pressurize the line.
Also try adding some fuel-injection cleaner to the tank to see if that improves the situation at all.
Q. I tuned up my friend's 2000 Ford Escort. Now, when she turns on the heat, you get a smell of gas. I replaced the fuel filter and checked the connections. Could the heater core be bad? When the heat is off, you don't get any smell.
A. There is nothing that smells like gasoline in the heater core. You've got a leak in a fuel line or in an evaporative-emissions-system hose, a solenoid valve that's stuck or any of a hundred other things.
But it's not the heater core: Fuel or fuel vapor is being sucked into the plenum from inside the engine compartment.
Q. I have a 2005 Volvo XC70. When it was approaching 20,000 miles, I thought I should have the tire rotation done.
My husband told me that his BMW dealership had warned him that a car with all-wheel drive should not have tire rotation done, or it will lose all-wheel-drive function. I got online to research more. I couldn't find anything to indicate that a car with all-wheel drive should not have tire rotation.
A. Every industry source I could find says that all-wheel-drive cars need regular tire rotation, the same as any other vehicle. Twenty-thousand miles is kind of late - I'd rotate every 10,000 miles.
Q. I have a 2002 Dodge full-size B-350 Maxiwagon, a 15-passenger van. I use it mostly for hunting and camping trips. You never have to pack anything, just throw it in and slam the door. Nice!
Except for one small quirk: In colder weather all the windows fog up, unless I turn the defroster on full blast. Only the defroster! Then they stay clear. If I turn on a multiple setting, such as the defroster and lower discharge for the feet, everything fogs up in minutes.
Not too hard to deal with in the spring and fall here in Wisconsin, but during the winter it's terribly cold on the feet. Any suggestions?
A. Are you running in fresh-air or recirculate mode? Fresh-air mode will keep the windows dryer.
Otherwise, my only suggestion is a couple of aftermarket fans to move some more air around.
Mike Allen is a senior editor for Popular Mechanics magazine. Questions should be sent via e-mail to driveit@nytimes.com.
