When Vehicle Engine Misfires
Engine not running on all cylinders, either intermittently or continually.
(1) Stop the engine and endeavor to restart with the starter motor to check the state of the battery and connections. If the battery is in a low state of charge, it will need recharging from an independent electrical supply, and the charging circuit should be checked as directed under charging circuit below.
Before making the test on the H. T. equipment you are advised to note the warning below:-
[WARNING:- A warning is given against the possibility of electric shock when handling the H. T. (High Tension) equipment. The danger will be eliminated by giving careful thought to the action anticipated, before carrying it out.]
(2) Remove the cover from each sparking plug in turn and check:-
(a) By raising the cover from the plug terminal about 1/4in. "7mm" whilst engine is running. Sparks should be heard jumping the gap regularly.
If no spark is present on one or more cylinders:- (i) remove and check the sparking plug concerned (ii) check for moisture on the H. T. leads or distributor (iii) check, clean and reset the distributor contact-breaker points to .014 to .016 in. "0,35 to 0,40mm" as necessary (iv) check the distributor cap for cracks and the plug leads for faulty insulation
If the spark is irregular on all cylinders:- (i) check for moisture on H. T. leads or distributors (ii) check the distributor points, clean and reset as necessary (iii) check the distributor cap for cracks and plug leads for faulty insulation (iv) check the L. T. connections for tightness and cleanliness (v) check for flashing or blueing of contack-breaker points. If present, the distributor condenser should be removed (vi) check for a fault in the ignition circuit by connecting a wire between the "A" connection on the voltage regulator box and "SW" connection on the coil thus by-passing the ignition switch. At the same time, the wire from the ignition switch must be disconnected from the coil. Leaving the ignition switch off.
NOTE:- when making the above test remember that the "A" terminal is at battery potential. Connections to it must not be allowed to make contact with the metalwork of the vehicle or automobile otherwise a short circuit of the battery will result.
(b) Listen for any audible alteration in the running of the engine, as each cover is lifted. No alteration will indicate that the sparking plug in question is at fault:- (i) remove and replace or clean the plug; reset the gap to .029 to 0.32 in. "0,75 to 0,80 mm" as necessary.
(3) If the "missing" is accompanied by "spitting back" through the carburettor intake, while the engine is running. Persistence of this complaint points to the need for an engine overhaul.
IF THIS POST IS HELPFUL, PLEASE, DO SHARE.
This is a post from an automobile mechanic who loves to blog on mobile devices.
Healthy vehicle gives you healthy living. Visit your auto-specialists regularly and pay them handsomely.