MG Car Repair: 1976 Midget (1500), bright sun light, coil wire


Question
QUESTION: I am trying to get the car running for the first time since overhaul. I can't get any spark..the engine turns over but wont fire. Have no idea where to set the distributor to make sure timing is "close" to get it started. Any thoughts?

ANSWER: Hi Mark,
What do you mean? You said you have no spark but you want to set the timing????? You can't set timing if you have no spark. You have to have a spark to be able to time the spark.

Confirm that you do have a spark first. Pull the coil wire out of the distributor cap and place a spark plug on the end of the wire and lay the plug on a metal part of the engine. Then have someone spin the engine over with the starter while you watch the spark plug for a spark. (not in bright sun light) The spark should be thick as a pensile lead an blue in color. If you have that, proceed. If not or if you have a thin spark like a hair and yellow or orange in color stop and let me know as you need to do other work before attempting to set timing.

If you do have a good blue spark, pull all the spark plugs and put the car in high gear with the brake off. Roll the car forward while you hold a thumb over the # 1 plug hole until you feel compression, then look at the timing marks on the front cover and align the notch in the front pulley with 10 degrees BTDC (before top dead center) and stop. If you pass it you must back up a lot and approach it again and stop at 10 deg. Now the crank is roughly set to time the distributor. Remove the dist. cap and remove the rotor and look at the trigger wheel and you will notice it has four small pins imbedded in the edge of the circle. These are magnets that pass by a pick-up. Place the spark plug on the end of the coil wire again and loosen the distributor pinch bolt so you can rotate the distributor. Turn the ignition key to on and rotate the distributor clockwise until you see a spark at the plug and stop and tighten the pinch bolt. Now, replace the rotor and position the wires in the cap so that # 1 wire is in line with the rotor and then continue counter clockwise in the cap with the rest of the plug wires in the firing order ( 1,3,4,2). Then look up the timing specs on the sticker under the hood (if it is still there) Set the timing with a timing light if the specs are not there for US models at 2 degrees ATDC at 800 RPM.

Let me know how you do.
Howard



---------- FOLLOW-UP ----------

QUESTION: Thank you for your quick reply. I have no spark... no arc, nothing

Answer
With no spark you first need to look in the distributor to see what kind of ignition system you have. The original system most likely has been replaced with either an aftermarket electronic ignition or even a contact pointed system. Let me know.

Also you need to test the coil. Remove the wires off of the connectors and take an ohm meter and measure the resistance across the primary (+ to -) Let me know what it is.

You can do a rough preliminary test by removing the coil wire from the center of the distributor cap and attach it to a spark plug and lay it on a metal part of the engine. Then remove the wires from the (-) side of the coil (usually white w/black tracer) and attach a test lead to the negative post and with the key on, scratch your test lead across a metal part of the engine to see if the plug sparks.
Let me know,
Howard