What to do when your car won't start

Important Notes

What to do when your fuel-injected car won't start

First, let's look at the obvious: the battery. When the battery is run down, but the headlights seem to shine at full strength, usually the starter makes click-click-click noises. That usually means you need a jump start. Of course, if the headlights are dim or off entirely, the battery is the most likely candidate.

Keep in mind that jump starts do not always work. I used to find that cars with larger engines usually worked the first time. The quality of the jumper cables was also an issue. I tried jump-starting with cheap cables and it rarely worked. That was back in the old days, when I drove 1970s cars with V8s. Now, alternators are generally better, you may have more success.

A word of caution from Mark Monte when jumping a car with a dead battery. “The final connection of the jumper cables should be the negative, made directly to the engine block--this is done to prevent a spark near the battery which may explode if it is venting hydrogen gas! A new concern is the power spike created when the dead car's alternator comes on line--since many new car alternators are sensitive to the voltage spike created when the dead car starts and consequently lose their diodes. This can be an expensive repair. In order to avoid the spike it is necessary to remove the alternator from the circuit by un-plugging it (often a two-wire plug which energizes the fields) before the jump-start is attempted, this unfortunately reduces somewhat the voltage available to start the dead car! Let the running car charge the dead car's battery for awhile, first, and then un-plug it. In this case, patience can be a virtue, and improve the chances of success. Good luck!”

If the battery's in fine fettle, there are a few other problems that could cause your car to refuse to start. First, check the gas. Yes, I'm serious!

Then check the computer codes - click here for instructions. Often, the computer will know what is wrong, but it is not infallible.

Next, turn the key and listen carefully. On most Chrysler cars, you can hear the electric fuel pump engage for a second or two as soon as you move the key from OFF to RUN (not START - it will still engage but you might not hear it). If you do not hear that, there may be a failed relay, fuse, or fusible link, or even a bad fuel pump. You might want to try testing your car for this before it refuses to start, so you will know whether you can hear it or not. (If you can fold down your rear seats, and you have a sedan or hatchback, do so - the fuel pump is in the back).

A clicking noise from the starter indicates (usually) a dead or dying battery, and (sometimes) a dead starter. This may be a common problem on 3.3 family engines as they grow older.

If the engine turns over, you may want to check for a broken timing belt. On many cars, you can peek in and see the timing belt directly. That is not the most likely problem, but having had a Spirit R/T, it's one I'm keenly aware of. Most Chrysler engines can deal with broken timing belts easily, and without the loss of the valve train and pistons!

Ed Hennessy pointed out that the auto shutdown relay may be bad. "That will cut power to the coil and the fuel pump. This is the relay that looks for the distributor to spin, and if not, it cuts fuel and spark to avoid problems such as when there's an accident. The relay could be bad and the fuel pump won't ever burp.

"You can try feeding power to the fuel pump directly. Because of the ASD circuit, you can cheat and do this easily. Connect 12V+ from the battery to the positive terminal of the coil. That will back feed 12V to the fuel pump through the ASD circuit. If the pump runs, the ASD relay is bad. If not, the fuel pump or its wiring, etc. is the problem."

Also try disconnecting the MAP sensor, which can cause a car to not start without setting any fault codes! If you disconnect it completely and properly, the car may start, in which case it is definitely the MAP sensor.

Another common problem is the Hall effect sensor, which in effect tells the computer where the engine is. This is easy and inexpensive to replace (as is the MAP sensor, come to think of it.) Even though Neons have no distributor, they still used Hall Effect sensors, on the block; other distributorless cars also use them.

There is also an engine fuse which might have blown - along with various fusible links.

George wrote that if there is no fuel, the problem could be either the fuel pump or the fuel gauge itself that makes it impossible to use all the gas in the tank. Adding gas may help.

Dale Berry pointed out that old or bad spark plug wires, especially moist ones, can cause non-starting, and suggested that you check all spark plug wires, check for moisture or carbon tracing in the distributor cap, and consider excessive water in the gas. He also pointed out that a completely clogged catalytic converter and flooding could cause failure to start. Your car's owner's manual should have instructions on what to do if the engine is flooded (has too much gasoline).

John Smith had starting problems, mostly when cold, on his 250,000 mile Dodge Spirit. He found oil in the neutral (?) switch next to the transmission dipstick. Cleaning the connection seemed to fix it.

A related switch problem can be solved by starting in Neutral rather than Park (this tends to affect the older, TorqueFlite equipped vehicles).

A leaky fuel injector or weak fuel pump may also cause problems. To diagnose these, click here.

John Auto Tech picked this up so quickly we suspect it's a common problem: a mid-80s 2.5-powered car wouldn't start. The Hall Effect sensor and auto shutdown relay had been replaced already, and the MAP sensor was not at fault. No electricity was at either coil terminal with the key in ON, but the engine still cranked. John wrote: "repair the burnt-out fuseable link in the wiring harness next to the left shock tower."

In one case, a Power Ram 50 had no start after installing a new engine, though there was spark; the injector wasn't firing. MacMichael pointed out, “are you sure you hooked up the ground strap from the intake manifold to the firewall? —this occasionally gets forgotten after doing engine work." (Thanks, swalve.)

Those are the most common causes of not starting, but we are always open to feedback on more systems.

One contributor noted:

A perfectly running, recently tuned car died and would not restart. It turned out to be the ignition rotor. The bad rotor was only a couple weeks old and looked perfect. There was spark at the spark plugs so that test alone is no indication. There were no codes set in the computer and I tested everything in the ignition and fuel system. As I was about to tear dow the engine and check for jumped timing belt I discovered it was the defective rotor, partly by luck.

It is impractical to carry all kinds of spare parts in your car, but carry at least a rotor ($8) and probably a cap ($10) as those are cheap and very easy to replace, under 5 minutes. Your rotor, no matter how new or perfect looking, can fail any time and leave you stranded, as it did to me. It is your $8 insurance against at least one reason why you might need a tow.

If you car is not starting or stalling and you are about to pull your hair out, try a new rotor and a new cap, even if the ones in the car are very recent. It just might do it, and it is a cheap fix.

This also emphasizes the need to really dig into the basics of ignition before proceeding with more exotic tests. In my case, cap, rotor and wires were brand new, but don't discount possibility that some of those may be defective, even if they LOOK perfect. Some tests can be unreliable and insufficient, as I learned from the spark plug test that looked OK despite the bad rotor. In this type of situation, a swap test might be the easiest one. Next time you do your tune up, keep your old cap, rotor and wires, that you KNOW are working, albeit old. That way, you can always try them back on in case something is wrong and quickly eliminate many possibilities.