Fireball xr700 problems

[mish_man121]

i just recently got an old ke70 wagon with a 4k-c. it has a fireball xr700 set up but its having problems. they bloke before have the resistor for the coil on the - instead of the + so i swapped that around and she started up beautifully then dribbled out, the the negative from the fireball unit to the distributor had a loose connection so i put a new 3 point connection in and it started up nice but then dribbled out. if any one could give us any ideas for it would be appreciated.

http://s1294.photobucket.com/albums/b601/hamishbrown/

and there are a couple photos of parts i need. the bit of the interior for the drivers door and the plugs for the back of the original head units

cheers, hamish

[Dazza]

I would be checking the resistor to make sure power is still passing through it. When your ignition switch is in the start position with the starter motor turning, you should be getting battery voltage to your coil. When you let the key turn back to the run position, the coil should get its power from the resistor which should be around 9 volts.

[mish_man121]

rightio thanks mate. i tried that on the weekend and got 3 or 4v coming out of the resistor. is that too low?

[ta22fan]

Looks like you've got a Bosch GT40 series coil fitted. Can't tell from the photos exactly which one tho. The old GT40 is a 3 ohm (12V) coil designed to work without a ballast resistor in circuit. GT40R is a 1.5 ohm (9V) for use with ballast. GT40T is a 3 ohm, and GT40RT is a 1.5 ohm. If it's a 3 ohm coil - bypass the ballast resistor. 1.5 ohm - you need the resistor in circuit between battery and +ve coil terminal. I don't know these engines, but anything with points will often work best with a 9V coil plus ballast (and a 12V "start" feed to the coil direct from the starter motor).

[mish_man121]

yer its a gt40r thought i can only get 3 to 4v to the pos of the coil. could this be causing the weak spark? how can i fix it.

[ta22fan]

Yep - 3-4V sounds way low. Most likely cause is a faulty ballast resistor. Connect the 12V wire that runs to the ballast directly to the +ve coil terminal and give it a quick try - not too long or you'll cook the coil. If she runs like that - replace the ballast resistor and put the wiring back as it was (your other option is to replace the coil with a 3 ohm / 12V unit and leave the ballast out of circuit permanently). Also not a bad idea to clean and reset the points.