Diagnosing Hard Cold Starts and Stalling When Pulling Away

Part numbers are from the manufacturer's original catalogue. Check them against your VIN before ordering.

• Socket and wrench set
• timing light
• multimeter
• fuel pressure gauge (for fuel-injected engines)
• vacuum gauge
• carb cleaner
• spark plug socket
• feeler gauge

1. Start with the ignition. If the distributor was installed without alignment marks, the timing may have shifted. Bring the No. 1 cylinder piston to TDC on the compression stroke and make sure the rotor points to the No. 1 cylinder terminal. Check the wire order by cylinder. For the inline-four GA13 the firing order is usually 1-3-4-2, but verify it against the markings on the cap and under the hood.
2. Set the ignition timing with a timing light on a warm engine at idle. The value is given on the label under the hood. If the distributor is a used one, check the operation of the vacuum and centrifugal advance mechanisms. The vacuum hose must not be pinched or disconnected.
3. Inspect the distributor cap and rotor for cracks, carbon tracking, and signs of arcing. Check the gap of the pickup or the points, if the distributor has them. Check the spark plug wire resistance with a multimeter, and check the condition of the ignition coil. Replace the spark plugs if they are old, and set the gap according to the label.
4. Fuel filter: make sure it is installed in the direction of the flow arrow and that the fittings and clamps are not drawing in air. Check that the hoses are not kinked. There may be a restrictor inside the filter that blocks flow if it is installed incorrectly. If the filter is installed backward, fuel delivery is poorer under load and the engine stalls when pulling away.
5. For the fuel-injected version, measure the fuel pressure with a gauge. It should match the value in the service specifications. Also check the fuel pump strainer in the tank, and the pump relay and fuse. If the car is carbureted, check the fuel level in the float chamber, the operation of the accelerator pump (a jet of fuel should squirt into the throat when you press the pedal), and the condition of the fuel pump.
6. Cold start, carbureted version: check the choke plate. It should close fully on a cold engine and open as the engine warms up. Check the operation of the automatic choke, the gap and linkage, and the fast idle on a cold engine.
7. Cold start, fuel-injected version: check the coolant temperature sensor. Its resistance should change with temperature. Check the auxiliary air valve or the idle regulator: it should give a higher idle speed on a cold engine and lower it as the engine warms up.
8. Finding air leaks: inspect the vacuum hoses, the intake manifold gasket, the air intake duct bellows, the brake booster, and the PCV valve. If the distributor and filter were replaced, a hose may have been left disconnected or damaged. Check for leaks with carb cleaner on the running engine: when it hits a leaking spot, the engine speed will change.
9. Stalling when pulling away often means a lean mixture or ignition that is too advanced at low rpm. Check the idle speed, the mixture adjustment, and the correct installation of the distributor. If the car has an automatic transmission, also check the transmission modulator vacuum hose and the idle speed under load.
10. If you have not found the cause after all these checks, perform a compression test on all cylinders and check the valve clearances. An old engine with leaking valves is also hard to start cold and runs unevenly at low rpm.

• When working on the fuel system, keep open flames and sparks away, and wipe up any spilled gasoline after disconnecting hoses
• Do not check for spark by holding a spark plug wire in your hand
• If you cannot set the ignition timing after installing the distributor, remove the distributor and reinstall it using the TDC mark
• Do not try to compensate for the error by adjusting the carburetor