Please be the ignition coil!

[BamaFrazier]

Tried to start my starboard engine (inboard Mercruiser 454, 7.4L, Thunderbolt)couple of weekends ago and couldn't get it to fire. Seemed like the starter was giving it juice, but couldn't get anything but a few little "pops" out her. I replaced all the plugs today, and nothing changed.

Does this sound like I need to replace the ignition coil? Or, shoudl I be thinking fuel pump?

Thanks!

GF

 

[electricaldoctor]

The ignition recipe calls for three different ingredients. Air, fuel & electricity. I would firstly check to see that the flame arrestor is not gummed up with crud. Take it of to clean it. While it is off, you can check for the presence of fuel by holding the choke butterfly open with a screwdriver and have someone pump the throttle a few times. Do not turn the ignition key yet or you could singe your eyebrows if it backfires up through the carburetor. You should be able to see gas squirting. If it is getting lots of air and fuel, the next thing to check is whether you are getting spark at the plugs. If you are missing any of these ingedients, your engine cannot start. Find out what you are missing and we will go from there.

 

[OldSkool]

You can check the spark by first making sure the engine compartment is purged of any fumes. Remove any of the spark plug wires and install a spare spark plug onto the wire. Since you just replaced them you should have a extra. Lay the plug on the engine block to ground it. (Don't hold it with your hand.) Turn the engine over and see if it sparks. If not then it could be in the distributor or the coil. Usually I replace the coil, cap, and rotor when I tune an older HEI equipped engine.