All, my 71 was having problems sputtering / slow response after it warms up.
I had heard the ignition coil may be the problem.
where did you hear this? It's not unheard of I suppose, but it's also a common mis-diagnosis of a poor running engine.
Anyway, I replaced the coil and in the meantime also replace the solenoid. Now it cranks but will not fire. This wasnt a problem before I replaced both of these.
Coils can be tested. With the piss-poor quality of modern parts from just about every source (including coils, but not as often as other parts) you've just now added two completely new possible bad parts.
Why did you replace the starter relay/solenoid? It very likely has nothing to do with any of the symptoms you first listed. While again it's not impossible, it's just low on the list. Was there something else going on, perhaps with the way the starter was working, that made you decide to replace the relay?
The main reason I ask is back to the quality of modern parts. The worst offender across all categories is very likely the replacement Ford starter relays. In fact, it's so common to have defective ones right out of the box, it's practically a joke these days.
Basically then, keep your old one if you have not already thrown it away. It was working before, so it's at the very least a good working spare. But it might be a saving grace if your new one fails.
The first thing to do when this happens is to put the old parts back on. Your new coil could be defective. It could also be wired incorrectly. Can you trace and explain each of the wires? There are way more than normal, and any of them could be causing the trouble.
What kind of distributor are you using? Points or electronic? Is the coil an exact replacement for what was working previously? If you have an ohm-meter, test it out compared to what is expected of a stock coil (if stock is what you had previously?).
I have pictures attached, if anyone can confirm wiring is set up correctly. I did also note that I have 12volts going into the solenoid and about 10-11 going out when cranking, not sure if that would account for the lack of firing or could my problem now be something else.
Your wiring is correct at the starter relay. Looks good and clean and relatively new battery cables. But they can get old under the skin, so to speak, so need to be checked now and then.
The 12v to the first terminal is correct. Should be exactly battery voltage so double check that as a slight drop on a battery cable could equal a much bigger drop when the starter is pulling power to crank.
And the 10-11v is probably normal. The less drop the better of course, but any time the starter is cranking it's pulling the battery down and dropping the rest of the electrical system proportionally. Is this original wiring other than the battery cables? Looks to have been messed with at least a bit judging by the non-factory crimp connectors on the coil.
A way to test if the starter relay/solenoid is dropping voltage through it would be to disconnect the starter end and have someone hold the key to START and measuring voltage at that point. If it remains 12v then the relay is not a problem.
Next time you replace battery cables, go with big ones so your voltage drop during starting is minimized. Yours look like 4ga already, and that's good (original was likely 6ga?), but if you have the chance to use 2ga don't pass it up because people think it's overkill. What's a couple of extra bucks to have extra capacity?
Another test of the relay is to disconnect the Brown wire on the small "I" terminal there on the right. If the engine now starts (you said it has spark though?) then the relay is defective and somehow grounding out that I terminal. The Brown wire is connected to the ignition coil's positive side, via the red 3-wire connector at the back of the engine. The Red w/green stripe wire from the key to the coil goes into that plug, where the Brown wire is spliced into it. Helps to add extra voltage and current carrying capacity to the coil for easier starts.
Paul
