Solved: 18R-G Igniton Problem

[river]

Hi,

Hmm... if you turn the ignition to "on" (not "start") and the oil/amp lights are on, does the heater/vent fan work?

seeyuzz
river

[twentyEight]

Hi,

Hmm... if you turn the ignition to "on" (not "start") and the oil/amp lights are on, does the heater/vent fan work?

seeyuzz
river

Sure does!

[o_man_ra23]

jumping tacho would suggest to me that there is an earth problem with your motor. The tacho runs on a pulse signal from your coil and increases RPM with the frequency of the pulse signal, so it seems that you are getting some high frequency interference, often found with a bad earth. Check the resistance from the housing of your condenser to the negative battery terminal, should be all of about fark all. If it isnt, then you need to check your earths. Otherwise, it could be a dodgy connector on a wire.

Cheers, Owen

[river]

Hi,

Okay. That means your main relay is working. I'm just rying to determine where the problem is by eliminating some things. This means your ignition (key) switch is okay, your fuse is okay, you're getting power through the fuse and the main relay is operational.

Which brings us back to the dizzy, coil, leads, spark-booster (if you have one)...

seeyuzz
river

[airfireman1]

Try running a small jumer wire from the positive of the battery to the positive of the coil and the crank to see if you have a spark. Same as hot wiring a car. If it has spark with this then the problem is betewwn your ignition switch and your coil.
cheers

[The Witzl]

bad earth for sure

[twentyEight]

Thanks for the help guys... You can be assured it is appreciated!

[twentyEight]

bad earth for sure

Do you mean:

Something that shouldn't be earthing, is? or;

Something that shoud be earthing, is not?

[joecoolmk2]

your points may be earthing out all the time, or you could have a broken wire somewhere. you need a multimeter to check for these things.

[airfireman1]

What he is trying to tell you is check the earth strap from the battery to the chassis and also the earth strap from the chassis to the motor.
Make sure all the connections are clean and tight. It would not hurt to do the same with the positive from the battery as well.
Cheers

[twentyEight]

What he is trying to tell you is check the earth strap from the battery to the chassis and also the earth strap from the chassis to the motor.
Make sure all the connections are clean and tight. It would not hurt to do the same with the positive from the battery as well.
Cheers

Done that, and also tried direct from the battery to the pos on the coil and crank...

[o_man_ra23]

The points etc earth through the body of the dizzy to the timing cover, to the block to the body then to the battery. Try cleaning up your connections from the dizzy body to the timing cover, the dizzy clamp does a lot to do this.

Cheers, Owen

[airfireman1]

OK into fault finding mode:::::ull the dizzy cap off and crank the motor over, check that the rotor goes around and around. Check points gap and also check that the wire that connects to the points on the outside of the distributor is secure, also check the wire from the inside of the distributor to the points is not earthing out before it reaches the points.
Check that the points gap is within specifications. Check that the distributor cap is in good condition and that the carbon button in the centre of the cap is in good condition and that it is making contact with the rotor button. Check the rotor button to make sure it is securely located and not cracked.
connect a multimeter to the side of the dizzy and an earth point use it on the ohm setting,crank the motor over and watch the needle on the meter or lcd display to check that it is pulsing each time the points close and open.
Recheck all electrical connections.If you have 12 volts to the coil and still no spark it is allpoints to the dizzy and either bad connections or bad earth
Cheers

[twentyEight]

The points etc earth through the body of the dizzy to the timing cover, to the block to the body then to the battery. Try cleaning up your connections from the dizzy body to the timing cover, the dizzy clamp does a lot to do this.

Cheers, Owen

Thank you... This has fixed my problem!

Strange that it was working fine and then stopped earthing after not even touching the dizzy!

Oh well, at least it's fixed again!

[twentyEight]

Hey airfireman,

By your name, I'm guessing your an aviation firefighter... Are you Airservices or RAAF?