Made the swap to electronic ignition and the car barely runs now

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Markzilla88

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I have been trying to tune my 72 Demon with a 360 with a points style distributor for a few weeks now. I have to start by saying I’m relatively new to this. It ran okay, but there was definitely more power in the car that wasnt getting made. The car generally ran sluggish and crappy, and wasn’t as snappy as I remember it being when i got it a year ago. I’ve watched videos, and read many articles on here and online about getting the timing dialed in and tuning the carb for optimum performance. Somehow through my tuning I had turned a decently choppy cam into a smooth idle, I had given the carb occasional hesitation, and occasional random bogging at wide open throttle.
I went to a friend who is a big mopar guy for some advice on what to do. He noticed I had an existing wiring harness for electronic ignition, so I ordered the swap kit from Mancini and installed it using the pre existing stock electronic ignition harness. We checked continuity in all the wires and it all checked out and looked good on the multimeter. We started the car and the car sounded good, nice and strong start. We turned the timing to 10 degrees btdc and the cam chop came back to life. We adjusted the idle air mix screws and idle screw on the edelbrock 1405 and it idled great. When we went to restart the car however, the starter now has a VERY hard time starting and slowly cranks the motor over. It’ll still fire though, but barely turns the motor over. On the ride home it ran great, tons of mid range power that it was lacking before. Only thing I noticed was that it would pop out of the exhaust every once in a while after I got out of the throttle, and at stops lights it would yank like a dog on a chain (I figured this is partially or wholly from the cam). By the time I got home to park it for the night after a 20 minute ride, it would barely idle and run so rough at low rpms that it died as soon as you put it in reverse to get it in the driveway. It was so bad I had to bump the idle screw up to park it.
I’ve tried to adjust the timing some and retard it to get it to start easier, but it runs like crap now. I’ve readjusted the carb to get max vacuum (16”) and it still has a rough start, idles good, and then dies once you drop it into gear.
Any thoughts or advice is welcome as I’m spinning my wheels on this. Thanks
 
Pretty sure that the advance is coming in way to soon. Ask them for the distributor specifications.
 
Check your vacuum advance is hooked up correctly. You want ported not manifold vacuum.
 
I have been trying to tune my 72 Demon with a 360 with a points style distributor for a few weeks now. I have to start by saying I’m relatively new to this. It ran okay, but there was definitely more power in the car that wasnt getting made. The car generally ran sluggish and crappy, and wasn’t as snappy as I remember it being when i got it a year ago. I’ve watched videos, and read many articles on here and online about getting the timing dialed in and tuning the carb for optimum performance. Somehow through my tuning I had turned a decently choppy cam into a smooth idle, I had given the carb occasional hesitation, and occasional random bogging at wide open throttle.
I went to a friend who is a big mopar guy for some advice on what to do. He noticed I had an existing wiring harness for electronic ignition, so I ordered the swap kit from Mancini and installed it using the pre existing stock electronic ignition harness. We checked continuity in all the wires and it all checked out and looked good on the multimeter. We started the car and the car sounded good, nice and strong start. We turned the timing to 10 degrees btdc and the cam chop came back to life. We adjusted the idle air mix screws and idle screw on the edelbrock 1405 and it idled great. When we went to restart the car however, the starter now has a VERY hard time starting and slowly cranks the motor over. It’ll still fire though, but barely turns the motor over. On the ride home it ran great, tons of mid range power that it was lacking before. Only thing I noticed was that it would pop out of the exhaust every once in a while after I got out of the throttle, and at stops lights it would yank like a dog on a chain (I figured this is partially or wholly from the cam). By the time I got home to park it for the night after a 20 minute ride, it would barely idle and run so rough at low rpms that it died as soon as you put it in reverse to get it in the driveway. It was so bad I had to bump the idle screw up to park it.
I’ve tried to adjust the timing some and retard it to get it to start easier, but it runs like crap now. I’ve readjusted the carb to get max vacuum (16”) and it still has a rough start, idles good, and then dies once you drop it into gear.
Any thoughts or advice is welcome as I’m spinning my wheels on this. Thanks
KISS
What do the spark plugs look like?
Post some up close pic's of the plugs showing the ground strap, should give you a good idea of whats going on.
 
Looks like your not that far from me. Bring it over I'll get it to torch the tires just stabbing the throttle. Bring extra tires.
 
So the chop came as a result of putting it at 10btdc, definitely am not tuning it for the sound I’m just trying to get it to run well and consistent.

Vacuum advanced is hooked to ported (passenger side). Weird thing, last night when i went to check timing again just to be sure, I plugged the distributor vacuum line back up and it killed the motor instantly.

Picture of plug 1 coming up
 
8E3E90A6-C1DC-45E7-8A7F-E8B64B944637.jpeg
 
I’ve since leaned the carb out 8% in both cruise and power mode per the edelbrock tuning chart, but haven’t/can’t get it to run enough to get a new read on them
 
That looks to me like an unhealthy cylinder-compression wise. So yeah it can't burn the fuel=rich. J.Rob

Certainly has some oil on it. I’m working on a TR tune and when o got here the plugs look like that. After pulling some fuel out of it, the oil cleaned up. Maybe the OP will get lucky.
 
So the chop came as a result of putting it at 10btdc

^^^^That's not how it works. When a camshaft is "large" you can't get it to run smooth enough with any amount of initial timing over a certain amount-lets say 20-22 intial. This is due to the overlap. You need to recurve your distributor and give it what it wants to run the most efficiently (ie. smoothly) You may want 20 degrees initital and only another 14-16 "in the plate" and then we get into the vacuum pot travel and rate. Fix the timing before you touch the carb-You'll never get the carb right without the timing right first. J.Rob
 
^^^^That's not how it works. When a camshaft is "large" you can't get it to run smooth enough with any amount of initial timing over a certain amount-lets say 20-22 intial. This is due to the overlap. You need to recurve your distributor and give it what it wants to run the most efficiently (ie. smoothly) You may want 20 degrees initital and only another 14-16 "in the plate" and then we get into the vacuum pot travel and rate. Fix the timing before you touch the carb-You'll never get the carb right without the timing right first. J.Rob


EXACTLY
 
You gotta excuse my ignorance and elementary questions as I’m pretty new to this, but what do you mean by back side of the ground strap? I’ll glady take the picture, just don’t know what your talking about
 
It shouldn't have a hard time cranking with 10 deg. Have you verified your balancer actually corresponds to TDC on #1? Not uncommon for them to slip, and then you're chasing your tail.
 
You gotta excuse my ignorance and elementary questions as I’m pretty new to this, but what do you mean by back side of the ground strap? I’ll glady take the picture, just don’t know what your talking about
The ground strap is the L shaped piece of metal that protrudes from the plug threads to the gap at the tip of the electrode in the center of the plug.
Here this will help
Spark plug reading can be complex and sometimes frustrating task this page will help make it easier and the results rewarding
Read thru the above link
You can learn alot about the fuel and timing reading the plugs correctly.
Report back when you have read the link you will have a good understanding about spark plugs.
Dont be afraid to read it more than once its good info and is the key to tuning any engine.
 
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It shouldn't have a hard time cranking with 10 deg. Have you verified your balancer actually corresponds to TDC on #1? Not uncommon for them to slip, and then you're chasing your tail.
Yeah so I’m not 100% sure it hasn’t slipped. I just felt the rubber isolator ring piece in the middle of it and it feels pretty hard and has cracks in it which is making me think it’s old, and it could very well have slipped. I’ve got a new one ordered and will be at the store tomorrow morning. I’m going to focus on getting that replaced, making sure it’s actually marked accurately at TDC, then time it again, then tune that carb. I’m hoping that will cure some/all of these issues
 
YOU need to step back and use a piston stop. Over the years I've run into quite a few balancers that have slipped. Back in the day, 352/ 390 Fords

Get buy or make a piston stop. I HAVE HAD THIS ONE since the 1970's

Here one of my old posts:

====================================================================================

https://www.forabodiesonly.com/mopar/attachments/249-4795-jpg.1715053390/

Disconnect battery for safety. Insert the device in no1 making sure the piston is down. The length of the plunger is unimportant, but you want the piston to stop "down a ways." If you buy one rather than building one, make sure you get a lock nut on there to stop the stem from wobbling around

CAREFULLY wrench the engine around until the piston stops on the device. make a temp mark under TDC on your pointer tab, onto the balancer

Rotate the engine opposite direction do same thing. This will result in two temporary marks, and halfway between is TDC

If the original mark is correct, that is where it will be. This is one I built for SB Mopars in the '70s. Had it all these years

stop2-jpg-jpg.jpg


I've only seen 4 or 5 of these type here, commercially made, and in fact have one came in a Summit degree wheel kit. The plunger "wobbles" unless you screw it all the way in and tighten it down. So if you want it shorter you need to come up with a lock/ jam nut to make it rigid

249-4795-jpg.jpg
 
Yeah so I’m not 100% sure it hasn’t slipped. I just felt the rubber isolator ring piece in the middle of it and it feels pretty hard and has cracks in it which is making me think it’s old, and it could very well have slipped. I’ve got a new one ordered and will be at the store tomorrow morning. I’m going to focus on getting that replaced, making sure it’s actually marked accurately at TDC, then time it again, then tune that carb. I’m hoping that will cure some/all of these issues
Start with a fresh set of plugs, if all the plugs look like the one you posted they are junk.
 
Geez guy, Steve invited you over to get it runnin good at 10:30 this mornin and you're still here fightin it out on an internet forum?
 
crappy idle and rough running...fuel pressure more than 5 psi for an Edelbrock? Is it dumping fuel out the boosters at crappy idle?
 
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