SOLVING STARTING PROBLEMS
Tool and Material Checklist:
It's every driver's nightmare: You get in your car, turn the key, the engine turns over, and-nothing. The car lust won't start. This booklet will help you get your car going again, whether it's the dead of winter or the dog days of summer.
FIRST THINGS FIRST
The source of your problem could be as simple as an empty gas tank. Just because the needle is well above EMPTY does not mean that the tank has plenty of gas; the fuel gauge could be broken. Also, on many cars the gauge will read FULL continuously if the sending unit isn't properly grounded. Put in a few gallons of gas before you start looking for other problems.
NOTE: If the tank is empty and your car has a carbureted engine, prime it by pouring a few tablespoons of gas down the carburetor. Fuel- injected engines will prime themselves If the key Is left in the ON position for a few seconds.
CAUTION: On carbureted engines, be sure to reinstall the air cleaner to prevent a backfire and possible fire,
An improper starting technique is a common reason for a no-start, particularly In cold weather. It's not true that the more gas an engine is given, the faster It will start. If an engine Is given too much gasoline, it will flood and won't start at all. Most carbureted cars are started by pressing the pedal to the floor, releasing it, and turning the key with your foot off the pedal. In cold weather, two pumps of the pedal may be needed. Most fuel- injected cars are started without pumping the pedal at all. Check your owner's manual for the correct starting technique.
Once the simple answers have been ruled out, you must determine whether the source of the problem is lack of fuel or lack of spark. Although the fuel check is easy to do, it differs for carbureted, fuel-injected, and port fuel-injected engines.
CAUTION: Never use an extension drop tight when working on any part of the fuel system. To avoid a f Ire hazard, use a flashlight Instead.
CHECKING A CARBURETED ENGINE
1. Turn the key to the ON position and see if the ENGINE light comes on. If it doesn't, the problem is probably In the wiring.
2. If the ENGINE light does come on, remove the air cleaner and inspect the choke. If the car hasn't been run in six hours or more, the choke should be fully closed. If it's not, open the throttle; this should snap it closed.
NOTE: Protect your eyes by wearing safety glasses or goggles when doing this.
3. If the choke still won't close, it's either dirty, broken, or misadjusted. You can force it closed and hold it in that position by wedging a screw- driver between the air cleaner bracket and carburetor. (As soon as the car is running again, re- move the screwdriver so the choke can open.)
4. If the choke appears to be working, inspect the carburetor. While holding the choke open, move the throttle rapidly to the full OPEN position; fuel should squirt from the accelerator pump nozzles within the carb. If it does, proceed to the section 'Checking for Spark."
5. If fuel does not squirt, remove the fuel filter to check for restriction. The fuel filter is usually found behind the carburetor fuel inlet nut. Use two wrenches to. remove the fuel line, one on the inlet nut and one on the fuel line nut.
NOTE: If possible, use a flare-nut wrench on the fuel line nut; it is less likely to slip.
6. Place a rag on the manifold under the fuel line connection before unscrewing it. There should be clear evidence of filter contamination if it is the cause of the no-start.
7. If your car has an in-line fuel filter, place a rag under the filter and remove the clamps securing it in the fuel line. Contamination can be difficult to detect with this type of filter; you must replace it to find out if it's the cause of the trouble.
8. If the fuel filter is in good condition, check the fuel pump capacity. Connect a hose from the fuel inlet line to an unbreakable container.
9. Disable the ignition system by removing one of the primary coil wires, then crank the engine. If the fuel pump cannot deliver at least 1/2 pint of fuel within 15 seconds, it should be replaced.
10. Before removing the fuel pump, disconnect the negative cable of the battery to prevent an electrical spark from igniting spilled fuel. When in- stalling the new pump, be sure the pushrod or drive cam properly contacts the pump lever.
11. Another possibility is that the line leading to the fuel pump or the inlet sock in the tank Is restricted. Manually fill the carburetor float bowl, start the engine, and check the fuel pump pressure and vacuum to see if either of these is to blame.
12. If the fuel pump capacity is okay but no fuel is squirting from the accelerator pump nozzles, the problem is in the carburetor. On most cars, you can remove the carb air horn (the upper part of the carburetor) without removing the carburetor.
13. To remove the air horn, disconnect the fuel line, throttle, and choke linkage, along with any other necessary linkage rods.
14. Remove the screws holding the air horn to the float bowl; some of the screws might be hidden within the air horn.
CAUTION: Whenever you are working on or around the carburetor, be very careful not to drop screws or anything else Into It.
15. Lift the air horn off the carburetor; the float assembly and, in some cases, the accelerator pump will also come off. Turn the air horn upside down so that the float is facing you.
16. If the float is stuck in the UP position (down with the air horn turned over) the needle will re- main seated and no fuel will enter the carburetor. Another possibility is that the needle sticks in its seat when the float drops. In either case, replace the float, needle, and seat.
17. If the float bowl was full of fuel when you removed the air horn, inspect the accelerator pump. This pump contains a piston whose job it is to push fuel into the accelerator pump nozzles; if the piston is worn or damaged, replace it.
18. Some carburetors have a diaphragm-type accelerator pump in place of the piston. Remove the pump cover to inspect the diaphragm; if it is torn or damaged in any way, replace it.
CHECKING A FUEL INJECTED ENGINE
1. Turn the key to the ON position and see if the ENGINE light comes on. If it doesn't, the problem is probably in the basic power supply; consult your service manual or a professional mechanic
2. If the ENGINE light does come on, remove the air cleaner. Have someone crank the engine while you observe the fuel injectors to make sure fuel is spraying out.
3. If fuel spray is observed, disconnect the injectors. Again, have someone crank the engine; if one of the injectors sprays fuel now, either the injector or seal is faulty and must be replaced.
4. Before installing the new injectors, remove the spark plugs and clean them with dry cleaning fluid or plug cleaner. Crank the engine a few seconds with the plugs out.
5. If fuel spray is not observed while cranking the engine with the plugs out and the injectors disconnected, but it was seen initially, the problem is not due to a lack of fuel. Proceed to the section 'Checking for Spark."
6. If fuel spray was not seen initially, disconnect the injectors and attach a test light across the harness connector.
7. Crank the engine. The test light should blink on and off, meaning that the no-start is due to either a faulty injector or a fuel delivery problem.
8. To determine which one is the cause, turn off the engine and install a fuel pressure gauge on the Schrader valve. (The Schrader valve is located on the fuel supply line or on the fuel filter case.)
NOTE: Some cars require a high-pressure gauge, similar to those used for fuel-injection diagnosis. Consult the service manual
9. The fuel system should pressurize within a few seconds after turning on the engine. If so, this means that the problem is faulty injectors.
10. If the system does not pressurize within a few seconds, the problem is either a bad pump, a plugged in-line or in-tank filter, a restricted fuel line, or (on cars with in-tank pumps) a leaking fuel pump coupling.
CHECKING A PORT FUEL INJECTED ENGINE
1. Check the computer's memory for trouble codes; use your service manual for assistance. If no codes are stored, proceed to the section "Checking for Spark."
2. If the spark is found to be okay, disconnect the harness connector from one of the injectors and attach a test light.
3. Crank the engine while watching the test light. If it blinks on and off, install a fuel injection pressure gauge on the Schrader valve. (The Schrader valve is usually located on the fuel rail.)
4. Turn on the engine and note the fuel pressure after the pump stops. On most pod fuel injected engines, it should be between 30 and 40 psi. If the pressure is low, the cause is the same as those mentioned for standard fuel injected engines.
5. If the pressure is within the specified range, and if all other checks came out okay, proceed to the section "Other Possibilities."
CHECKING FOR SPARK
Once you've determined that fuel isn't the problem (or in the case of a pod fuel injected engine, before you check the fuel), the next step is to check for lack of spark. On older cars with points and condensers, this means simply pulling the coil wire from the distributor tower and holding it close to the ground while cranking the engine. If it sparks, do the same thing with one of the plug cables to make sure voltage is getting past the rotor and distributor cap.
CAUTION: On today's cars, this test is obsolete; you could end up with an electrical shock and damaged ignition components by checking for spark In this manner. Instead, purchase a special spark tester, available at most auto parts stores.
The procedure for checking spark is as follows:
1. With the engine off, remove one plug cable from a spark plug. Twist the boot a bit if necessary to get it off.
2. Install the spark tester on the end of the cable and attach the clip to a good ground.
3. While someone cranks the engine, observe the end of the tester. The spark should be well- defined and extend from the tester's center electrode to its housing.
4. Check the remaining cables in the same manner. It they all check out tine, you can be sure that lack of spark is not the problem.
5. If there is no spark, first remove the distributor cap and make sure the rotor turns when the engine cranks. It it doesn't, the pin securing the distributor gear to the shaft is probably broken, meaning that the distributor must be removed and repaired. Another possibility is that the camshaft timing belt or chain is broken.
6. If the rotor does turn without a spark, check for broken or disconnected pickup wires. It nothing is found, further inspection by a professional will be necessary.
If the source of the no-start has yet to be discovered, a few more possibilities remain. You may want to investigate any or all of the following:
1. Some fuel injected engines have a throttle- position sensor, or TPS. If this sensor sticks in the wide-open position, it will result in a very lean fuel mixture that can make starting the car all but impossible.
2. Water in the fuel system is a notorious cause of starting problems, especially in cold weather. Use quality gasoline and add gas treatment to the tank occasionally.
3. On a computer-controlled engine, if the cool- ant sensor fails to the extent that its circuit opens with the ignition off, the computer will act as if the temperature outside is very cold. This can result in a flooded engine and a no-start.
4. An EGR valve that sticks open can cause an overly lean air/fuel mixture during cranking. Re- move the EGR valve and make sure that its pintle is properly sealed against the seat.
5. If your car bucks and backfires when you try to start it, the camshaft timing chain or belt might have jumped. To check for this, turn the crank until the ignition timing mark on the crank pulley lines up with the pointer on the engine. Remove the distributor cap; the rotor should be pointing to the terminal for the first cylinder in the firing order or the cylinder 1800 across the cap. If not, either the engine has jumped time or the distributor's drive gear pin has sheared.