Pissed off with motor, want to change

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Check all the connections. Check to make sure the ECU/module is grounded
good to the fender or firewall.
I had a /6 that would idle all day fine. You try to put some rpm's to it. It
would buck and fart all over the place.
Had a 70 Cuda that would heat up the coil so bad that it wouldn't start.
Was the box not grounding good.
 
Mopar to ya said:
It is stock electronic ignition as far as I know. Voltage at battery with vehicle off is 12.55v. Voltage at positive post of coil key on engine off is 4.7v. Voltage at positive post of coil key on engine on is 7.2
I have it running, and when I turn the distributor counter clockwise or advanced, it pops louder and more often. When I retard the timing and can actually see the timing marks with my gun, it pops less or almost never until I put a load on the motor. I actually drove it today and it had absolutely no power and began to backfire a lot (after idling with no popping for 5 minutes). My next free time is Sunday and I am going to do a compression check. Can a carb load up and cause exhaust backfiring only?
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So there is 4.7V with the key on, but engine not running? And 7.2 with engine running?
It sounds to me that your ignition is the issue. I agree with verifying the grounds are good, both between the box and the cowl, and also from the cowl to the engine. In certain circumstances I will run a ground wire from the case (scratch off the paint if painted) to the rear intake bolt (clear off paint if it has it).
Also, the ballast resistor... As a test, run a jumper wire between the two connectors on the ballast. (assuming this is a 2-post ballast). Then fire it again and see if it still pops. If it doesn't pop you need to shop for a new ballast with a lower ohm rating than the one you have. Do not drive around with the ballast by-passed. Only run for a short time.
Set your base timing to 12° and leave it until you get the popping fixed. Then you can mess with timing.
 
Just for fun, rotate the engine to TDC and take 2 pics of the of the distributor, 1 with cap on, one with removed. Be sure to clearly show where the rotor is in relation to the pickup, and where the centering pin in the rotor is relative to the distributor shaft
.
 
1wild&crazyguy said:
are you using the 5 box and or 4 prong ballast?
Click to expand...

It has a 4 prong ballast. I was going to mention this and forgot ... after I had the car running for twenty minutes or so and I shut it off, I touched the ballast resistor and it was hot enough that had I done more than a glancing touch I would have been burned. I know resistance = heat, but should it get that hot?
 
Mopar to ya said:
It is stock electronic ignition as far as I know. Voltage at battery with vehicle off is 12.55v. Voltage at positive post of coil key on engine off is 4.7v. Voltage at positive post of coil key on engine on is 7.2
I have it running, and when I turn the distributor counter clockwise or advanced, it pops louder and more often. When I retard the timing and can actually see the timing marks with my gun, it pops less or almost never until I put a load on the motor. I actually drove it today and it had absolutely no power and began to backfire a lot (after idling with no popping for 5 minutes). My next free time is Sunday and I am going to do a compression check. Can a carb load up and cause exhaust backfiring only?
Click to expand...

These figures sound fairly normal, but that doesn't mean the coil output is weak, or that you have an open wire or broken plug.

You need to run a compression check and/ or ground each plug one at a time. This will tell you if it's in one or two specific cylinders.
 
jimmyray said:
Just for fun, rotate the engine to TDC and take 2 pics of the of the distributor, 1 with cap on, one with removed. Be sure to clearly show where the rotor is in relation to the pickup, and where the centering pin in the rotor is relative to the distributor shaft
.
Click to expand...

I can do that tomorrow morning. I appreciate the help and everyone asking questions and for info to help nail this down! I am thoroughly frustrated right now.
 
briankaplan said:
Check all the connections. Check to make sure the ECU/module is grounded
good to the fender or firewall.
I had a /6 that would idle all day fine. You try to put some rpm's to it. It
would buck and fart all over the place.
Had a 70 Cuda that would heat up the coil so bad that it wouldn't start.
Was the box not grounding good.
Click to expand...

I thought of that and ran a ground wire to the box. No dice.
 
I have to admit I am feeling a small ray of hope due to all the feedback and questions I am getting. Sunday is compression check day. Tomorrow morning pics of dizzy that were asked for and I will try and get a recording of the backfiring to post. It is so sporadic. Can a carb cause this? I have suspected I have carb issues because before this cam I was playing with the secondaries to try to keep it from stuttering on WOT. I would hit it and it would fall on it's face, then stutter and take off.
 
How are the connectors on the ballast resistor? Are they factory or new spade connectors?
 
Good news is, the intemittent nature likely rules out the mechanical problems, e.g. wiped lobes. Could be sticking valves, but I would think it is electrical. Just out of curiosity, what condition are the plug wires in? Are they all separated and away from metal? It is possible the wires can be grounding out or crossfiring. Odd, but it happened on my 81 Mirada with cheap wires.

Also, the fire inside the cap could be firing the wrong plug at the wrong time. Hence, we want to see the location of the rotor relative to the cap and wires at TDC. As the distributor introduced mechanincal or vaccum advance, the position of the rotor inside of the cap at the firing event changes, and the spark has to jump the gap. If things are out of alignment (cap wires, reluctor in shaft, etc.) it can crossfire, and only occasionally at that!

Make sure you get a pic of the distributor, from the top down, with the cap AND rotor button off as well.

As the distributor advances, the rotor is at a different position and the spark has to "jump" across the gap, which it does even when everything is perfectly aligned.
 
jimmyray said:
Good news is, the intemittent nature likely rules out the mechanical problems, e.g. wiped lobes. Could be sticking valves, but I would think it is electrical. Just out of curiosity, what condition are the plug wires in? Are they all separated and away from metal? It is possible the wires can be grounding out or crossfiring. Odd, but it happened on my 81 Mirada with cheap wires.

Also, the fire inside the cap could be firing the wrong plug at the wrong time. Hence, we want to see the location of the rotor relative to the cap and wires at TDC. As the distributor introduced mechanincal or vaccum advance, the position of the rotor inside of the cap at the firing event changes, and the spark has to jump the gap. If things are out of alignment (cap wires, reluctor in shaft, etc.) it can crossfire, and only occasionally at that!

Make sure you get a pic of the distributor, from the top down, with the cap AND rotor button off as well.

As the distributor advances, the rotor is at a different position and the spark has to "jump" across the gap, which it does even when everything is perfectly aligned.
Click to expand...

I'll get pics, but had at TDC and verified rotor pointing to #1 on cap. New cap, rotor, plugs, wires, coil, ignition module and ballast resistor. Made my own Accel wires and just bought a pre-made set as well. I agree - the intermittent nature points to electrical, not mechanical issues. Pics will be posted tomorrow morning.
 
This is what I was saying about just getting a good old point dist as a back up dist. So few wires, so little to go wrong. You can use good old solid plug wires also

Points fired engines for over 70 years, almost every engine up to the 70's had them.

So cheap, so easy yet how people have forgotten them
 
Mopar to ya said:
I'll get pics, but had at TDC and verified rotor pointing to #1 on cap. New cap, rotor, plugs, wires, coil, ignition module and ballast resistor. Made my own Accel wires and just bought a pre-made set as well. I agree - the intermittent nature points to electrical, not mechanical issues. Pics will be posted tomorrow morning.
Click to expand...
\

What about changing the pick up coil inside the dist, those can and do go bad
 
Not to my knowledge. a lean carb can cause spitting back through the carb, though.

However, at TDC, when timing is set to 0, the rotor should be 5-15 degrees AFTER the #1 wire location on the distributor. Therefor, as the mechanical advance kicks in, the it gets closer to center and then a few degrees positioned BEFORE the #1 wire location.

Obviously, the cap and distributor body are stationary during the entire event, but the shaft that the rotor/reluctor is attached to is "spring loaded" with the advance weights, and actually changes relative position to fire the cylinder earlier. This is obvious when you remove the cap, and you can rotate the rotor button shaft 30 degrees or so, while the engine is off.

If you are using a "stock" distributor, it may be putting as much as 30 degrees mechanical in, as well as another 10 degrees vacuum, for 40 degrees total. If you set the timing at 15 degrees like you mentioned, then you could literally be firing at 55 degrees BTDC!

Since the Distributor rotates once for every 2 engine rotations, that means the spark has to jump 1/2 that range of advance, e.g. 27.5 degrees.

360 degrees/8 = 45degrees. If the starting position of the rotor is aligned too close to the #1 position on the cap. Thus, when you add 27 degrees, you are over 1/2 way to the next cylinder in rotation, and all kinds of weird things happen.

FWIW, unless you have limited the amount of mechanical in the distributor, I would not go past 10 degrees BTDC.
 
Anything that causes unburnt fuel in the exh can cause popping. So yeah, the carb could be the culprit. It's just the lessor of possible causes and the cheapest way to eliminate the more immediate possibilities is to diagnose the electrical. IMO, the ignition voltage to the coil is low and there's a lot of voltage drop. But like Wild said, it's possible that is just a normal situation. That's why I say test the ballast legs, or just jump them to get as much voltage as you can to the coil and see if the pop disappears. If it doesnt, it's more than likely the carb. If it does, it's the ignition wiring. I just don;t like buying stuff to diagnose. Free info is always the best....lol
 
jimmyray said:
However, at TDC, when timing is set to 0, the rotor should be 5-15 degrees AFTER the #1 wire location on the distributor. Therefor, as the mechanical advance kicks in, the it gets closer to center and then a few degrees positioned BEFORE the #1 wire location.
Click to expand...

Jimmy you are getting way way WAAAAYYY off into left field here

THE CHANGES IN MECHANICAL ADVANCE DO NOT CHANGE THE RELATIVE POSITION OF THE ROTOR

This is because the timing of the spark relative to rotor is TIED to the rotor position by means of the reluctor The two are hooked mechanically together an CAN NOT change--unless something is loose.

THE ONLY TIME a rotor changes "rotor phasing" which is exactly what you are referring to, is changes due to VACUUM ADVANCE or a mechanical problem in the distributor itself, such as poor mechanical tolerances, loose shaft, improper reluctor installation, etc.

The reason VACUUM advance changes rotor phasing is because it is NOT tied to the rotor. Vacuum advance effectively moves the spark postion without corresponding move at the rotor. However, this IS designed into the distributor. So unless there is something loose, or the vacuum is "over advancing" or the dist. is badly worn, a non issue.
 
Okay, here are the pics of the dizzy. It was running pretty nicely at idle with occasional popping. When I revved it it would backfire a bit more. When I snapped the throttle wide open it backfired through the carb for the first time. Finally got it running pretty well. Timing at 12 degrees BTDC. Pretty much quit backfiring at idle. Hooked up vacuum advance and idle ran way up. Still ran nice, good throttle response. Took it for a drive and absolutely no power. WOT and I got maybe 35 MPH. No backfiring though. I turned the next road and started home and it started backfiring loud and often. Put in neutral and backfiring stops. Coasted home. I have a couple videos of the backfiring as well. Kind of hard to hear, but it might help. http://www.youtube.com/user/branchingout3#p/a/u/0/FMbJ3auUgE8
http://www.youtube.com/user/branchingout3#p/u/0/p6u5ufKdinA

View attachment Distributor with cap.jpg

View attachment Distributor with rotor.jpg

View attachment distributor wo rotor.jpg

View attachment Reluctor.jpg

View attachment Reluctor close up.jpg
 
Ok, 2 questions. Was your damper at the 0 Mark? Are you sure you did not install the distributor 180 off?

If your timing was set to 12 TDC, the the reluctor should be about 12 degrees clockwise of the pickup nipple. Are you sure you are not timing it at 12 after TDC?
 
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