Electronic ignition troubleshooting help

[Bee1971]

I guess I celebrated too soon. Won't start today. It has spark. So now I'm guessing a fuel issue. But it won't even fire up with starting fluid (doesn't even really sound likes it's trying to).

So with spark and fuel there, what else can I look at?

This

 

[Bee1971]

I have good spark at the distributor tower, so I think the ignition system is working.

This

Post 24 / 25 / 27

And here we are a month later still talking about the ignition system

What am I missing

 

[Curt Chambers]

This

Post 24 / 25 / 27

And here we are a month later still talking about the ignition system

What am I missing

You're not missing anything. That's exactly the way it happened. One day it started and 2 days later it wouldn't. That's how I knew the distributor was in correctly. And ever since then I've been throwing money at new parts.

I checked the link to HalifaxHops distributor check, and according to that mine is OK. I have a strong steady spark, but it's yellow. Some say that is bad. Others say no big deal. I don't know if I should even still be looking for an ignition system failure, or looking at something else.

 

[Don Frelier]

Timing chain jumped?

 

[Curt Chambers]

Timing chain jumped?

I sure hope not. But I'm starting to wonder now.

 

[Don Frelier]

You can do a rough check by turning the crank to TDC on the timing tab on the compression stroke. The rotor should be at or just passing the #1 tower on the cap. If it's not even to the #1 on the cap then most likely the chain jumped.
Just something to rule out.

 

[Curt Chambers]

Moved the engine to TDC on the compression stroke (using a compression gauge) and in the process made sure that the distributor was rotating CCW. Verified that the distributor was installed correctly and the rotor was pointing to the #1 tower. Verified firing order at 1-8-4-3-6-5-7-2.

Is this good enough evidence that the timing chain hasn't jumped?

As for the yellow spark issue, not sure what else I can do to pursue it other than swapping distributors. And if the yellow spark is in fact acceptable, then the ignition system would appear to be in good order. Which puts me all the way back to the beginning. I don't think lack of fuel is causing the no-start. Over the last month I've sprayed a whole can's worth of starting fluid into the carb without so much as a hiccup. Not saying that there can't be issues with the carb. But it should have at least started by now.

So what next?

 

[64fury74charger]

I will throw in a suggestion here. Another way to check the timing chain is pop of the distributor cap and then rotate the engine from the crank until you see the rotor move in the distributor. Then move the crank pulley back until the rotor moves. There should not be any slack there.
Timing chain slack is a bad thing. Just my opinion and experience and that’s all.

 

[Don Frelier]

I should apologize. I went back to your original post and it sounds like a new rebuilt engine.
The chain shouldn't have jumped.
But you know the distributor is set up correctly anyway (I know little consolation).

 

[Bee1971]

Start snapping pictures of your ballast resistor and wiring harness

Coil pictures and wiring and post here

Did you ever disconnect your main engine wiring harness from your bulkhead connector and looksy

You can probably pull that whole engine harness in less then 30 minutes

I found this one time , crimped end wasn’t making proper contact - Was literally under the rubber sealed end of a Newer Wiring Engine Harness that went to the coil - I found it while literally taking an ohm meter end to end and then moving the wire around with my hands after I pulled the complete harness off the car after some years - Went thru everything Ignition related like your doing

Man I wish I was closer - A second set of eyes woud bee nice

 

[Bee1971]

MSD Blaster Coil that was intermittent until it finally popped on the Highway

 

[Don Frelier]

FYI - I did recommend inspecting/cleaning the bulkhead (Post 91)

 

[Bee1971]

I don’t think anything has been missed or repeated twenty times in this thread already honestly

LOL

Sucks , wish someone was closer to put a second set of eyes

 

[64fury74charger]

Somewhere in the wiring there may be some broken strands and it’s not popping out because it’s inside the insulation and makes contact intermittently. I have spent countless hours chasing wires.

 

[Curt Chambers]

The bulkhead connector was cleaned, inspected, and tested during the restoration process. The entire wiring harness was tested prior to installation because I didn't want to have to deal with issues like this after reassembly. But that doesn't mean there's not a problem in there somewhere. I tested for continuity and inspected for visible damage. But I didn't take individual wire resistance measurements. As has been pointed out, there may be a number of marginal connections which, when added up, is enough to take away a volt from the coil which I guess is enough to degrade the spark enough to prevent it from starting (although that still doesn't explain why it won't start when 12v is applied directly to the coil). I'll check the easy stuff, like the bulkhead connector and engine harness, but the thought of going deeper, of disassembling the dash to get at the rest of the harness, gives me the chills.

I'm not sure what's going to happen next. This car has been fighting me for 3 years and I don't have much patience left. I used to enjoy working on old cars, even when they didn't start. I'm not enjoying it anymore. At this point it might be best to cut my losses and sell it. I'm sure I'll live longer.

Thanks to everyone for your suggestions.

 

[64fury74charger]

For what it’s worth I have had most of the wiring in my Charger out on the ground and tested, cursing and all that and when it “tested “ good and was back in there were more issues. I have made several changes and made some harnesses myself and this has helped a lot. Now I just figure I am going to go through this process until everything is where I want it to be.

You will get this sorted out. I am not saying that it’s any fun, but you learn as you go.

 

[LowBikeMike]

Ok. You've confirmed distributor timing and spark at 1 plug (at least) so you know for sure you're good there. I'm thinking the "yellow spark" is a rabbit hole and not the real issue based upon some of your other writings. As this point I would use an inline spark tester on each wire individually. This will tell you if the plugs are actually firing in the cylinder. If you have a weak system the plug might fire when removed from the engine, but will not fire under cylinder pressures. The inline tester will find that. If you have fire on all cylinders that leaves a air/fuel or spark timing issue. Since you said fuel is NOT a problem, I would pop a valve cover off and watch the valves. Roll it back up to TDC on #1 and see where the valves are. Even with a weak spark the thing should pop, fart or cough at the least. Has the timing tab been replaced?

You can check timing chain slop as noted above, but expect somewhere less than 5 degrees of slop, you will have some slop, if not the gears wouldn't last very long.

 

[MoparGuy68]

I'm not sure what's going to happen next. This car has been fighting me for 3 years and I don't have much patience left. I used to enjoy working on old cars, even when they didn't start. I'm not enjoying it anymore. At this point it might be best to cut my losses and sell it. I'm sure I'll live longer.

This is an awesome post! I know exactly how you feel. Yes, it is like fighting a war against the car.. I’ve been fighting for the past year with mine. Like you I also vocalized on here the possibility of calling it quits and giving up and getting rid of the car. We can’t let our cars defeat us and claim victory over us!

This coming weekend I’ll be trying to determine whether I need to replace the carburetor. Now I’m thinking it might be the problem. As three weeks before my no start situation began, my carburetor was making strange noise.

Before I attempted to start the engine this past weekend my float bowl was very close to being full with gas. I even manually filled it to the bottom of the sight hole with a syringe, so I know when I was attempting to start the car this past weekend that the float bowl was completely full with gas. Maybe my jets are clogged..

My 71 Charger is SO wide I can’t lean over the fender far enough to look straight down the carburetor. I’ll probably have to hold my cell phone over it and take a video, while I work the throttle, to check if gas is actually squirting into the carburetor. It sounded like gas was squirting when I work the throttle but I wasn’t able to visually confirm it.

I’m also going to be pulling spark plugs and checking to see if they’re wet. I learned a trick from watching uncle Tony that if you pull the plug wires a little bit away from the plug so they are slightly detached that will create a hotter spark when it jumps the gap. Helping to make a wet plug generate a spark and start a flooded engine.

Will try another ECU box and ballast resistor, once I get the stuck hold down screw, and acorn nut, out of my engine harness connector.

 

[Don Frelier]

I’m also going to be pulling spark plugs and checking to see if they’re wet. I learned a trick from watching uncle Tony that if you pull the plug wires a little bit away from the plug so they are slightly detached that will create a hotter spark when it jumps the gap

Not buying that one, making the spark jump twice does not give you more energy.
If that was the case; wouldn't all ignitions be hooked up that way all the time?
Either pull the plugs and hit them with a heat gun/torth or open the choke and throttle plate fully with no pump shot and crank it.

 

[RJRENTON]

Not buying that one, making the spark jump twice does not give you more energy.
If that was the case; wouldn't all ignitions be hooked up that way all the time?
Either pull the plugs and hit them with a heat gun/torth or open the choke and throttle plate fully with no pump shot and crank it.

Not entirely true....re a series cap in the spark path. Several years ago, the major spark plug manufacturers (Champion, AC, Autolite, Prestolite, NGK) marketed a "booster gap" dedign, where there was a fixed series gap (~ 0.060") directly below the terminal connection, inside the upper insulator, b4 the main electrode. The purpose was to allow for a zero resistance gap that allowed the spark energy to build up to the point where it jumped this series gap. Therefore, containing more energy to jump the smaller (typically 0.035" gap) inside the combustion chamber. An excellent design that overcame fouling deposits on the "business end" of the plug.
In Champion speak, the nomenclature was a "U" designation (ie UJ-12Y, UF-14Y, etc). Other manufacturers had similar identification designations. The booster gap or series gap design was used extensively in the piston engine air craft due to the heavily leaded fuels and in 2 cycle engines where oil was mixed with the fuel, resulting in carbon formation on the electrodes. These plugs are still available today. The use is limited due to addition ignition "noise" pollution generated by this addition series gap. Your B.S. premise is incorrect....it was a universally adapted dedign, that continued for many years.
BOB RENTON