Okay. The '64 Impala we recently acquired was really down on power. It "chugged" under a load and had a noticeable miss at idle. The miss wasn't any cylinder in particular - it just seemed like the ignition is weak.
First, the plugs were all carbon fouled. Second the rotor cap and distributor cap were pretty banged up. Third, the vacuum advance was seized up and the vacuum pot was toast. Last, the coil appeared to be original or close to it.
Thinking I was smart, I dropped an HEI distributor in it. It worked great, except I couldn't get the timing set properly because it hit the firewall. It was way too advanced. Back to the drawing board.
I re-installed the factory distributor with new points, vacuum pot and rotor cap. I freed up the vacuum advance as well. I installed a new distributor cap, coil, plugs and wires. When I tried to start it, it was pretty obvious the timing was way off. No backfiring or popping, but the engine was clearly fighting itself by firing at the wrong time. To be sure, though, I pulled a plug wire and installed a spare plug. Yep - spark so it must be timing.
This morning I brought #1 up to top dead center on the intake stroke. Sure enough, the distributor was out a couple of notches. I re-installed it properly and put it all back together.
No spark now.
I replaced the coil with the stock one. Same thing. I have voltage to the coil but no spark at the wires. What's that leave me with? The points close and provide the ground for the coil to fire, right? So I think that's all that's left?
Any advice would be greatly appreciated!
Hi Jim, try the HEI again.Just install it so you can adjust it with out hitting the firewall.Then install the wires in order but moved over one way or the other by one wire tower.
Thanks. Was thinking of doing that. I'd have to move all of the wires one post clockwise. I'm going to goof around with the stock stuff a bit more first. There's no reason it shouldn't work and it bugs me!
Hey Jim, now that you have the points base plate moving again maybe the little ground wire between the plate and distributor body is broken? Also remember that car uses a resistance wire at the coil + side. Dropping the voltage down a few volts. If you go with the HEI it needs a power source of 12 volts or what ever the battery is showing.
Thanks for the tip. I checked the ground wire and it looks good - it goes from the base plate to the distributor body. The wire that runs from the (-) side of the coil to the points looks good too. So strange.
When I had the HEI installed I ran a wire from the ignition-switched blade to the HEI. I've now switched back to the resistance wire setup. I can't find my voltmeter (in the middle of a move) but it's definitely stepped down based on the brightness of my test light. I need to get this thing running and over to the new place!
I'll keep tinkering with it. Worst case is the HEI goes back in.
The link below provides my complete Ignition Troubleshooting Procedure for the old style points and condenser ignition systems and is basically the same despite the fact it was written for old tractors.
On "some" points ignition systems on 12 volt vehicles an external series voltage dropping (12 down to 6) Ballast Resistor (or resistor wire link) was used so there was only 6 volts left for a 6 volt coil HOWEVER when the starter motor is cranking a ballast by pass system was used which supplied unballasted battery voltage to the coil direct by passing that ballast resistor or wire. That (by pass) was the I terminal, on Ford Solenoids or a similar terminal on GM solenoid systems.
If at all possible I would use the GM HEI for a much higher energy spark then the old points system. Its possible to have the distributor on the wrong tooth (if necessary for physical placement) but still get in time you know since rotation of the whole distributor can account for any off tooth changes. A timing light can be used to see where the No 1 piston is at TDC relative to when she fires and rotation of course changes that. When No 1 is at TDC on compression power stroke the points should just break open or the magnet pass by the pickup on an elec ignition and the rotor tip is lined up with the correct dist cap tower. But I'm sure you already know that
John T's Ignition Troubleshooting Procedure:
Thanks John. I was in the process of removing the stock distributor when I saw this e-mail alert come through.
I'm ready to put the HEI back in and try to adjust the wires on the towers to get the timing right BUT if I can make the stock distributor work I'll pop it back in. Here's where I'm at.
I do have a resistance wire on the coil that drops the voltage down. I also have the lead from the starter that bumps it up to 12V while cranking. I do have voltage on the (+) side of the coil with the key on.
Here's where I'm a little confused. I can see a condenser mounted to the base plate in the distributor. It's connected to the same lead as the (-) wire from the coil. I checked and the new coil is an external-resistance coil. I popped the stock one back in just in case and it doesn't work either. BUT, there is another condenser looking thing mounted to the coil bracket that is connected to the (+) side of the coil (that makes 3 wires on the coil - resistance wire, starter wire and this other thing). Should it be? Should that be on the (-)?
Jim, BEST I RECALL NO WARRANTY On some GM there's a condenser on the + input side of coil that has to do with radio and noise interference and nothing really to do with the ignition system. They were also found on the old vehicles with Generatros for same purpose to reduce radio noise
In GENERAL on the coils + input there's a wire from the IGN switch, a wire from the solenoid to by pass the ballast while cranking, maybe a noise reducing condenser. The coils - side wires to distributor and points
In the distributor the condenser is in parallel with the points to ground so on the points terminal you have the wire from the coils - (via the insulated pass thru) and the condenser wire.
Look at my Troubleshooting Procedure where I say put a test lamp on the coils - to distributor terminal and as the engine is cranked over slow it will flash ON when points are open but OFF when they are closed, if not shes never gonna work
The HEI has much more spark energy.
Thanks again John.
I put the HEI distributor back in, with the wires rotated off one post counter-clockwise. I can now get the adjustment I need out of it. It runs a little rough, but it did before (which is why I updated all this stuff). It now has a solid miss on one cylinder that it didn't have before so I need to recheck the wires. The air cleaner base rests on the top of the HEI distributor but I'm going to have to live with that for now. It's not too bad - I can get it to seal on the top of the carb and still rotate the distributor.
I baked the fuse for the "Switched IGN" blade on the fuse box. I have no idea where it is, so I'm going to have to take a look at the wiring diagram. I currently have the distributor hooked up to a BAT terminal which means it continues to run after I shut the key off. Need to remedy that. Curiously, it runs much better with the key off. Don't know if there's something shorted somewhere or not. I have to take a closer look at it. I'm just happy it runs again.
Jim, that's about all I can do for you now not being there. I have no idea about that miss. I can say with an HEI Ignition the firing voltages can be higher (subject to plug gap) and you need good quality wires and cap and of course good plugs. One way I find a missing cylinder is I use an insulated plug wire tool to have her idling and remove one plug wire at a time to see if one makes no difference or not and if not, that's the faulty cylinder.
All I have to offer now
I'm sure the miss is either a wire not installed properly or crossed since I didn't have a miss before this debacle. I'm going to check the firing order starting with the "new" #1 on the cap. I appreciate your help!
Ok - I had the #5 and #7 plug wires reversed. It runs AWESOME. Better than it ever has. Still, though, I can't get enough retard out of it before it hits the firewall. I'm going to rotate the plugs another tower counter-clockwise to see if I can get it into its sweet spot. I'm afraid, however, I'll wind up running out of adjustment the other way. I'll then have to resort to putting the distributor in off one notch - or buying a small-diameter HEI dizzy.
And the heater core sprung a leak on the test drive. Ugh.
Oops - one tower counter clockwise is INCORRECT (just in case someone stumbles upon this thread in the future looking for advice). Moving the wires one tower counter clockwise advanced the ignition. Turns out I had enough adjustment as-is. Need to turn the dizzy clockwise to retard. It's all good now. That 327 hauls the wagon along really well.