Guest firebern Posted April 9, 2001 Share Posted April 9, 2001 I have a 19778 280Z What is the BDCC cut solenoid? I have a B&W wire at the end of the ballast resistor is this a ground? There are a green and red wire that went to the distributor terminal, what does that terminal do? Get I leave these unplugged now that I am converting to FOrd v8? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 9, 2001 Share Posted April 9, 2001 The BCDD is the unit that is mounted to the underside of the stock Datsun throttle body. It simply measures vacuum and uses that to cease the firing of the stock injectors when the car is coasting. Kind of a fuel cutoff for times when fuel is just not needed to reduce emissions. My inline 77 runs just fine without it Sorry I can't help you on the ballast resistor wiring. To the best of my understanding, it is there because the coil requires it to be. Some coils state they must be used with a ballast and others without so it depends on what coil you are using. I haven't tackled that one since I plan to go with coil packs and a aftermarket computer anyway. Craig Quote Link to comment Share on other sites More sharing options...
jimzdat Posted April 9, 2001 Share Posted April 9, 2001 And as for your other question, the red and green wires at that terminal block go to the transistor ignition unit--God only knows what they do once they get inside there Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted April 10, 2001 Share Posted April 10, 2001 I wish I could help you on the coil wires; looks like we need our resident Engineer (Pete) to chime in here. I too have wondered why some coils require ballast resistors while others do not! Time to get the bat signal out-Pete usually responds to the bat-light. Pete-where are you? Kevin, (Yes,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Drax240z Posted April 10, 2001 Share Posted April 10, 2001 Ballast resistors. Well what they do is limit the voltage going to the primary side of the coil. Most cars have a 12v electrical system, but for some reason I am not quite sure of, most coils can't handle those 12v. They take about 8.5 volts IIRC. It has to do with the heat generated when transforming from 12v up to 20,000v. If you remove the ballast resistor on a coil that requires one, you'll get a very short life out of the coil before it overheats and fizzles. Quite honestly I would think that the advancement is simply marterials, and that in the last decade or so, they have been able to make coils out of a material that can handle the added heat of a 12v primary, whereas the 60's-80's coils usually had a ballast resistor, because the coil material couldn't take the heat. That's my hypothesis anyway. ------------------ "Nothing is fool proof to a sufficiently talented fool." Richard Lewis - 1972 240z, Powered by a Nissan 2.8L Turbo Inline 6. Drax240's Turbo Site Beginners Turbo FAQ & Answers Quote Link to comment Share on other sites More sharing options...
Guest firebern Posted April 10, 2001 Share Posted April 10, 2001 Yeah well good enough, you helped me to figure out the ballast wires. I don't remember seeing any ballast resistor when I dismantled my coil and wires last time. Wait now that I am thinking about it... There was a cheap coil in parralel with the original one. The kind of coil you would find in a radio, a steel armature with a copper wire rolled core. I'm sure you know what I mean. So I thougth the guy tried to get a little bit more power by putting this coil in parralel. Do you think this migth have been to replace the ballast? Has for the green and red wire, for my V8 conversion can I forget about those? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 13, 2001 Share Posted April 13, 2001 Yeah, I think Drax nailed it. It was a heat thing back in the day. Metal cased coils and they used the best materials they had, but it wasn't enough. I also think that early on manufacturers were comfortable with using a ancient design on the coil with a resistor and saw no need to improve it. As emissions and such became more of a concern, they were faced with having to rethink all of the sub-systems of the engine and try to optimize things. No more, hey it sparks, good enough. Of course electronic ignitions were the next step and add computers and fuel injection and we're where we are today. Natural progression I guess you could say. Lone Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 14, 2001 Share Posted April 14, 2001 Not sure why they limit voltage to coils, but some cars like the 240Z will bypass the ballast resistor when cranking to get more spark. Firebern, that little coil sounds like an inductor used to limit ignition interference on the radio. Quote Link to comment Share on other sites More sharing options...
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