hey i have a all original 1973 cutlass supreme with a 4 barrel rocket 350 with 54,xxx miles and the only thing that is done to it and has been on it for 6 years is a msd 6a box. I tried to start it up about a week ago and no go and the day before that it ran fine. so over night it randomly lost spark? wtf? so for the last week ive been trying to find spark and cant find any none at the plugs or coil not even a spark jump from the msd box. all ignition parts are new only old ignition parts are the distributor and points but there is no corrosion on the points...car is and has been garage kept. any ideas?

 

Start testing.

Power to coil, resistance of points, points opening and closing properly, condenser good, MSD box good, etc.

I'd eliminate the MSD box first, then go on from there.

- Eric

 

All good starter things. I'd also check the resistance in the coil wire and spark plug wires. I found my old coil wire had close to 40 ohms resistance If it's too high you won't be getting much spark there. Normal for new wires is around 4-5 ohms.

BTW, if it has an MSD box, it's not an all original 73 Cutlass. Does it also have an MSD HEI distributor? If it does, good chance the coil pack is your problem.

 

thanks for the reply. i disconnected the msd box and still no spark and no voltage at the coil with key on...possibly the condenser inside the distributor?

 

I checked the wires and they were good. no its not msd hei its the oem distributor with points. All original meaning no major mods to throw anything off but just a msd box could be taken off in a few minutes and its back to original lol

 

Does the distributor turn while cranking?

If there isn't any voltage at the coil primary (low voltage) there will not be any spark. Unlikely that the condenser is bad and it is not the cause of no primary voltage to the coil.

There should be a pink wire to the primary on the coil that supplies reduced voltage in the run position to prevent the points from burning. The pink wire is not standard wire it is special resistance wire for this application. This wire may have burned or have a bad connection, trace it back to the firewall.

I believe there should also be a yellow wire to the coil primary from the starter solenoid to supply full battery voltage only while cranking. Is there voltage to the primary (low voltage) side of the coil while cranking?

 

HEI was the best $100 investment on a number of vehicles I own.
More than once I've bought non running vehicles, and they needed only the HEI upgrade.

 

... Or maybe a $10 set of points or a $5 condenser?

- Eric

 

yes the distributor turns while cranking and no voltage at the coils primary with key on or cranking... but the pink and yellow wires deff sound like they need to be checked

 

an HEI might be worth it. but like Eric said maybe points something simple like that...

 

If you're not getting voltage to the coil, then it sounds like you've found your problem.

Follow it through - either a bad connector, a bad wire, or a bad ignition switch.

- Eric

 

If you have the msd box disconnected and your back to the original setup on the distributor then I would run a jumper from the battery pos terminal to the coil + terminal and see if it will start. What the jumper does is take everything out of the equation and only runs off the coil and distributor. If it starts you are missing power when the key is on. Please note to turn the car off you will need to remove the jumper wire.

 

very true i will try to jump the car tomorrow and post what happens. also when the car first died i thought it could be a bad ignition switch like Eric said...

 

It could be, the jumper bypasses all that with the exception of the switch operating the starter. See what happens.

 

does anyone know where the ignition switch is located? its only 13 bucks at autozone might as well try it

 

It's the switch that you operate with the key to start and run your car.

 

what about this duralast ignition switch on autozones website part number ls442
it looks like a connector not the key cylinder...

 

The ignition switch is located on the top surface of the steering column way down under the dashboard.
You have to drop the column in order to get to it.

It does look like you describe.

- Eric

 

ok thanks for the info Eric!
does it sound like its worth digging into the column to replace it?

 

I'd test it first. Check the wires back to the switch.
Do the warning lamps and the fuel gauge work when you turn on the switch?
If they do, then the switch is fine, and the problem is after it.
Check the heavy pink wire that comes from the switch - it goes to the fuse block and to the coil. If it's got power, you need to check the resistance wire that comes out the firewall side of the connector plug and goes to the coil. The wire could be broken or the contacts could be bad.

- Eric

 

ok yeah the warning lights do come on when the key is switched to the ON position. good info ill check that pink wire tomorrow. the pink wire holds voltage with key on?

 

If you've got warning lights, then the pink wire has juice, and you need to look beyond it to the resistance wire that comes out of the firewall plug and goes to the coil.

- Eric

 

ok sounds good i will test that one out, thanks again for the info

 

You have to fight the urge to throw new parts at a problem before doing some basic trouble shooting.

 

that is very true. i just got 3.4 volts to the coil with key on but when cranking the engine it stays at 3.4 volts this was achieved by putting new ring connectors on the wires that go to the pos and neg posts on the coil (msd reconnected) without msd it has 11.4 volts. no spark at the spark plugs tho...i dont know why i started messing with it this late but i got a little closer to it firing up

 

I don't know about the MSD, but the other voltages seem okay for now.

You need to troubleshoot the coil, the points, the rotor, and the condenser now.

- Eric

 

yeah the msd is making things more complicated but i agree with you on those basic things
thanks for the reply

 

Recheck your wiring.

http://www.hotrodders.com/forum/ford...er-163216.html

 

ok thanks i will.

 

From what i've read here not knowing the wiring to the msd it appears to have a resistance problem 3.4v at coil and not able to carry the load, ie bad connection somewhere.Like i said not knowing the wiring on your car it should have 12v cranking to coil + from the starter and about 8v koeo koer with stock points system.

 

This is correct. I would, like I stated earlier, take the MSD box out of the equation an return it back to original and go from there. It will be easier to troubleshoot.

 

yes i agree im going to take it off now and see what i get

 

ok i took off the msd wiring and with key on i had no voltage to coil so i put the msd wires back to the coil and hooked it up to the batt and with key on 5.9 volts to coil. any ideas?

 

Did you find the resistor wire and trace it back to the bulkhead connector under the master cylinder?

 

yes i did it looked fine but i cleaned off the connections on it and still the same outcome

 

So you have no power to the resistor wire.

Next step is to find out where you do have power.

Annoying as it might be, it may be easiest to remove the firewall half of the plug and test at the connectors there.
There's a ⅜"-head screw in the center of the plug on the firewall side (under the mud and undercoating) - remove it and you can unplug the two firewall-side plug halves from the other side.

Unfortunately, I do not know which of the terminals is the one you're looking for, but I'm sure someone here who has replaced his resistance wire can tell you, or, in the worst case, you can follow the wire to find it.

- Eric

 

yeah i will test that out, it very well could be the problem. your instructions seem to be straight forward enough ill just follow the wire, thanks for the tip Eric

 

hey all i have not had much time to mess around with the car but today i poked around it and im still in the same boat with the spark issue and its really annoying me that i cant find the problem...it baffles me how it can run great one day and then just die the next and its such a simple ignition system

 

So just hotwire it through a MoPar ceramic ballast resistor and worry about the small stuff later.

- Eric

 

ok...not to be a pain but could you walk me through what you suggested ive never tried that before. would any external ballast resistors work like a Mallory, accel, or msd something i could just grab at the local autozone. thanks greatly appreciated