Fuel not accepted smoothly

Step 1: Is ignition system in proper condition?

Check battery voltage, ignition distributor, spark plugs, ignition coil, ignition timing, etc.

• Yes: Go to Step 2
• No: Repair or replace damaged ignition components

Step 2: Is engine in proper mechanical condition?

If the fuel acceptance is still poor after the electrical test, check for mechanical problems: Compression, basic adjustment of valves and engine oil pressure.

• Yes: Go to Step 3
• No: Repair or replace damaged components

Step 3: Is the throttle valve switch set coorectly?

• Yes: Go to Step 4
• No: Adjust switch

Step 4: No leaks in air intake system, system in proper condition?

See Engine does not start Step 8.

• Yes: Go to Step 5
• No: Repair leaks

Step 5: Is the auxiliary air device in proper mechanical condition?

Visual check of the auxiliary air device: in the cold condition the auxiliary air device must be partly open, but when the engine is warm it must be closed.

• Yes: Go to Step 6
• No: Replace auxiliary air device

Step 6: Is the air flow meter in proper mechanical condition?

For testing, see Engine does not start under Step 9.

• Yes: Go to Step 7

Step 7: Is composition of exhaust gas (concentration of CO) correct?

See the Test Chart for value.

If the concentration of CO is too high, turn the bypass screw in the air flow meter 1/2 turn counterclockwise. Measure the speed and the concentration of CO again. Make corrections in several steps.