Ballast Resistor - is it required in the ignition wire loop?
1973 Ignition question
- Thread starter pickman
- Start date
Yes. Should say in the instructions.
What kind of ignition do you have? Stock points? Pertronix? 123? Which coil? It depends.
Gentlemen, I had the stock distributor with a form of pointless ignition module from Mallory and had lots of missing , backfires, no idle. My coil is the one Steve recommended new and I purchased new plug wires from the source recommend by the forum. I changed the distributor to my old Mallory Unilite and wired per the instructions using the ballast resistor. The car immediately started and runs much smoother no missing and backfires. Hopefully now I can take your past advice and actually tune the carbs? Frankly I was ready to scrap the motor. The carbs had old gas in them for several years which may be a problem? I will give it a good go this week to tune. Maybe in the future the 123 ignition will be the final solution once the car runs properly. Thank you for following my trials!
Honolulu
Well-Known Member
Old gas... a pal stalled on head work on his 735i for seven years. When he finally got around to it, he found eight or so gallons of fuel that were surplus to his requirements, and gave said fuel to me. Didn't take long to filter it and use the stuff in various motors. Nothing wrong with it as far as I could tell. Humidity around here runs in parallel with the temperature - frequently above 80. Condensation - we don't need no ... etc. etc.
You should ditch the resistor. If the coil is above 1.5 ohm you should be fine without it. Just swapped my e-type distributor out with the 123 and it's great. Cleared up a bunch of issues...
The very old Unilite distributor has an internal advance -preset- 30 years ago it was a good upgrade. The wiring requires the resistor which once installed really helped my issues. I am interested in the 123 as a final solution. Stevehose suggested I wait until solving the backfire issue which I have solved. Now need to determine the best model for the 73 3.5L engine.
123 Distributors are not as well built as the original Bosch. The 123s will get oil migration in the cap close to 16K miles and will need to be sent back to 123 for either a replacement or repair. Have had both my 123s in Athena & Vern last 16K. Your mileage may vary.
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I've put 20k on my 123 so far no oil issues, the custom curve and other options available with a programmable curve make it an amazing device. See my 123 custom thread for possibilities. I just upgraded to the Bluetooth version and will keep my old one for a spare. A 47 year old mechanical and vacuum advance system is not going to be as accurate.
e9coupe.com
DIY - 123 Distributor Ignition Timing with Carburetors
I'm embarking into new territory regarding the potential of the 123 distributor that I think is being overlooked. I am no engine expert but from my research on the web (dangerous I know), that old school tuners used to set initial timing with a vacuum gauge and/or a "highest idle" procedure...
e9coupe.com
jmackro
Well-Known Member
tferrer is addressing the issue that began this thread: whether or not you need a resistor depends on the resistance of the coil you are using. If your coil is low resistance, and you pair it with a new, expensive 123 distributor, you risk frying the 123's electronics. Just describing the coil as "the one Steve recommended" doesn't help us advise you whether or not more resistance is needed.
If you get a 123 then you'll need a Bosch red coil and no ballast resistor - nothing else. Jay is right, otherwise it depends on which coil, points/condenser or electronic (Pertronix) etc you decide to use.
it is the type of questions searching for advice that cannot be solved
if you ask for advice you should remember that the people that can help you do not know your car like you do
an old car frequently means that many stock things have been changed so you might be anywhere
....maybe they will realize this sometime...maybe not
All the information is good feedback. I have seen good improvement by going back to the Mallory unilite, Bosch coil 221119030 (black), with the resistor. I got the idle down to 900-1000 RPM there is very little room to adjust the timing by advancing or retarding the distributor. The idle at low RPM is still rough with the RPM varying up and down 100 RPM with an occasional small back fire out the rear exhaust. Once warmed up I tried tuning by turning the idle adjustment screws - first closed them - then turned them out slowly - had no perceivable difference in the idle? The Mallory distributor is NLA the cap is low profile not accepting the plug wires very well. Thinking that the improvement by reverting to the other distributor may be the right direction, I would like to look at the 123 is there a recommended model?
Your issues are likely carb related, not ignition. Likely vacuum leaks and rich running who knows what else. What carbs do you have?
same issue, we might have to guess the whole setup to be able to help, hopeless
if this is carb related (as it really seems to) first step would be to put the carbs to their stock settings first before fiddling with mixture or iddle screws
32/36 DGV carbs agree it's running rich I am not proficient in carbs.
Agree with Steve - hunt for vacuum leaks. I had some trouble with a vacuum leak where one of my carbs was mounted, but that was with sidedrafts, whereas you have downdrafts. Remember that the brake booster is fed with vacuum from the manifold, so the leak could be in that system. Also, if your ignition is using vacuum advance, check the hose and connections there.
Also make sure the carbs are tight to the manifold with the bolts, they loosen over time. Check that all vacuum ports are capped and like Chris said if one is used for advanced make sure that it’s not leaking.
Based upon your advice I will remove the carbs and rebuild them document the jet sizes and start with new gaskets. These were not new Weber's so I don't know what they are. After a lot of investigating and this advice I agree there is very probably some vacuum leaks. The liquid chokes are both leaking so they need repair. Once this is complete I may again ask for some advice. I did purchase a sync tool so will be in the learning mode for the next month. Thank you for all assistance.