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Electronic ignition and ways to improve them

Started by Kern Dog, April 10, 2024, 12:57:39 AM

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Kern Dog

Like many of you, I converted my car from a points ignition system to electronic when I did a 318 to 44 swap in 2001.

CH 446.jpg

I went with the Mopar Performance kit sold through Summit Racing. It came with the distributor, the ballast resistor, an orange box ECM and the wiring. It worked but over the years, I've read Rick Ehrenberg from Mopar Action magazine criticize the distributors that were made for these kits from around 2000 to 2014. He said that they were Accel brand based on the GM HEI units scaled down to fit inside a Mopar style housing. These use light advance weights and light springs. His contention was that the small weights and springs led to unstable timing since the guts didn't have enough mass to them. He was right...I can look at the timing light and see the mark jump around a bit, even with a new build and fresh timing chain. This condition leads to spark scatter and reduced power.
Last Summer I was on FBBO and a member had a distributor kit for sale. He was going to build a 440 but decided to go with a 5.7 based 3G Hemi. This kit was originally sold by Rick Ehrenberg through his bay store, he named it the HiRev 7500. It is like the Mopar Performance kits of before but with supposedly better components. I bought the kit and put it on the shelf to mess with later.
For 22+ years, I've had the occasional no spark issue where I go to start the car and it has no spark at all. This is always random. It can happen on a first start after sitting, it can happen on a 3rd or 5th start of the day. Cold, warm, hot engine or weather. Many times, I start replacing parts until it starts. Sometimes I just walk away and come back later and it starts as if nothing was ever at fault. It doesn't happen that often so I haven't made a point to dig in and stop it until now.
The wiring is actually quite simple.

ECM 1A.jpg



Kern Dog

What is odd is that I've had the no spark and replaced say a coil or the ECM, then tested those parts on another car and it ran fine.
Okay...so maybe a bad connection existed and changing the parts resulted in a fresh connection that worked?
Maybe. Maybe not though.
What if something else changed?
I took the firewall bulkhead plugs off and cleaned the terminals, then packed them with dielectric grease and stuffed them back in.
The last no spark happened about 2-3 weeks ago. At that point, I cleaned the terminals, checked all connections everywhere and it has started and ran fine since then.
It is fixed then, right?
Maybe, maybe not.
It has always been random as far as I can tell. I've gone 6 months or more between instances of this problem. I get to where I forget that this problem is lurking, then it returns. It has even happened when I shut the engine down during cam break in to fix a leak somewhere. Yeah....the very time you absolutely need it to start fast and run and it just wanted to crank and crank.
For me, an intermittent issue is extremely difficult to diagnose. I'm lucky that I have a LOT of coils, ECMs, ballast resistors and distributors to swap in.

Only a few times has the car been running fine (sometimes even being driven) and then suddenly stall and refuse to restart.
A couple of times, I've sprayed ether in the carburetor and it has started up. This was after I already confirmed that it was getting fuel.
Sometimes when it starts after me changing something, I suspect that it might have started anyway regardless of what I did, as if it just decided it would now go ahead and work like it should.

marshallfry01

I recently bought an electronic ignition kit for my 383. Haven't put it on yet. It looks identical to yours though. Orange box, resistor, same style distributor. I'll follow along to see if there's anything I can do to make it more reliable. I've heard the orange boxes can leave you stranded.

On another note, how are you running that high rise intake and that tall air cleaner without hitting your hood? I have that same intake on my 383 with a Holley 750 and I'm afraid I'll have clearance issues with my stock hood. Do you have a drop base for the air cleaner?
1969 Charger 383/auto
1969 Charger R/T 440/auto (waiting to be restored)
1972 Chevelle SS clone 383 sbc
1959 Chevy Apache short bed stepside
1968 Charger (glorified parts car)
Yes, I know I have too many cars. My wife reminds me daily.

Kern Dog

The intake is an Edelbrock Performer RPM. I do have a custom dropped base for the air cleaner. I had a shop make it in 2001. I've since learned to weld better and can make another if needed.
I have the same type intake in my 383 Charger and it clears with the standard type air cleaner....

D 383 125.jpg

D 383 133.jpg 

Kern Dog

This Mopar Performance electronic distributor has an adjustable base to allow for a range of advance. You need these gauges to slide in the slots to get the amount that you need.

Mallory 1.jpg

At this angle, you can see as the number increases, they get thicker.

Mallory 2.jpg 

The kit came with springs.

Mallory 3.jpg

It is set to the 14 degree number but here is the curve it has. I plotted this today.

Graph MP.jpg

Notice how starts with the 20 degrees initial at a 1000 rpm idle and barely moves until 1750.
Then it tops out at 33 degrees at a very late 3000 rpms. 


Kern Dog

That Mopar Performance distributor was "tuned" to delay the advance. This was done over 10 years ago when the engine had a stubborn detonation problem. I tried all sorts of Band-Aids to stop the knocking. I forgot how late the advance came in!
Next up is another electronic distributor, this one sold by Rick Ehrenberg. (Mopar Action magazine) It is sold through his ebay store and called the Hi-Rev 7500.
I installed it as it was made with no modifications. Here is the curve I recorded with it.

Graph Hi Rev 1.jpg

Note how it immediately starts advancing right from idle. It is almost a steady climb until 2750 rpms where it jumps 6 degrees, then another 6 by 3000 rpms. Holy crap...50 degrees of advance??? 


Kern Dog

Next is that Hi-Rev with the FBO limiter plate installed. The FBO plate looks like this:

FBO 2.png

Timing 4.jpg

I have the plate installed at the 14 degree mark. Here are the numbers I found with it in place:

Graph Hi Rev 2.jpg

It actually allowed 15 degrees but that is fine. Notice how it still starts gaining advance right from idle but then levels off by 2500 rpms.   


Kern Dog

It idles better. It revs quicker and smoother. It does seem to like the added advance from idle and up.
I drove it and it seems to just rev easier and smoother than before. ZERO detonation despite more advance and and earlier advance. MORE power? Maybe....The tires just spin!

Kern Dog

Here is another observation:
When the engine is cold, it also runs better and seems to warm up faster. I am guessing this is because before at a fast idle around 1750 or so, it was still running with only 20-21 degrees of advance while now, it has about 31. Engines aren't running clean and efficient when they are cold and trying to warm up so that is why they need more fuel and I'm guessing, more spark advance. The engine doesn't feel choppy or want to hesitate when cold like before.
Score!

armor64

interesting about the faster warm up, i guess because the "fire" starts earlier in the cycle, there is more time for the fire to heat the cylinder walls before the magic happens. Is there any difference in the running temps? Does it look like it running hotter after thermostat opens / stable temp?

Kern Dog

It seems fine.
This car has always run a decent temperature. The only time I've ever run hot is during camshaft break-in in the summer since I've forgotten to put an auxiliary fan out front.

Kern Dog

This Hi Rev distributor performed flawlessly on the approx 1000 mile round trip to Southern CA and back.
Easy starting, smooth running, no misfires, always had spark.
Better cold idle, better low speed performance.
SCORE !

Kern Dog

I am not sure if I have posted much about my random issue where the ignition system fails to produce a spark.
In the past, this happened only when I start the car after sitting awhile or after I've ran it a bit. It never lost spark and conked out when it was already running.
Until yesterday.
It was weird....The car has been sitting for several weeks, enough to where it probably lost a little charge to the battery. It started fine and ran well. It was a 90 degree day, I was about 3 miles from home and with the engine already near operating temperature, I leaned on it a bit. It responded as usual, strong and fast.
I made a U-turn and headed back home but with a car coming, I laid on it and rapped it up to around 6000 rpms and shifted to 2nd. It ran fine but then quietly stalled and would not restart. I coasted to a shady spot and popped the hood. There was plenty of gas, the accelerator pump shot was normal. I wiggled wires but nothing helped. The wife came out to get me, I went back home to gather parts and tools. Back to the car, I tried to start it but at this point, the battery was down to 11.96 volts and even with the jumper box, it only turned over really slow. I got the trailer and dragged it home.
With the battery recharged overnight, I tinkered around with it today and discovered that it barfed both the ballast resistor and the ECM. See, first I changed the ballast and when it didn't start, I put the original ballast resistor back on, then tried changing the ECM. When it felt like it tried to start as I released the key, I figured the ballast could still be bad. It was.  I've never seen two ignition parts conk out at the same time until now. I keep spare ballasts, ECMs and a distributor in a bag in the trunk but until today, I wouldn't think that I'd need to replace two components.
I tested the bad parts on another car to confirm their condition. The car wouldn't start with the parts so I tossed them.
All is well at this point. Just a tip for you to file away in your noggin if you didn't already know...You can have two ignition components fail at the same time, leaving you confused as to why changing a part at a time didn't help.


Mike DC

 
Two independent electronic failures at the same time?  That's absolutely Peak-PITA.  Congratulations.


Some old Mopar NASCARs raced with twin pairs of ballasts & voltage regulators mounted on the dashboard.  If the first one failed they could switch the harness connectors over to the second one in a few seconds. 

I'm starting to wonder if that's necessary for street cars these days, with the failure rates of replacement parts getting worse all the time. 


About 2 years ago there was a magazine article about a guy who toured all over Europe in a '73 Satellite.  He had twin copies of many ignition parts.  Some of the twin items were both wired up already and he could flip between them with a toggle switch.  Probably inspired by backup systems on aircraft.   

That car was impressive for how real-world it was.  The motor was just a mild 318 but it had a big radiator & shroud anyway.  The door mirrors were electric ones from a new LX Challenger.  Etc. 

b5blue

Weak idle ALT. output can do this.

Kern Dog

Once the engine warms up, the alternator seems to charge great at idle until I have the Heater or A/C going. THAT really draws a lot of power. If I'm sitting at a stoplight at night with the brake lights, headlights and A/C or heater fan going, the amp meter is below 10. That is discharging and would drain the battery pretty quick. I don't know how long, but when you're "charging" below 12.6, your battery is not going to last very long.

John_Kunkel


I know I'll incur the wrath of the "Mopar only" crowd, but long ago I gave up on the Mopar Electronic Ignition and alternators in favor of aftermarket ready-to-run distributors and Quality Power alternators that still maintain 13+ volts at idle with everything running.

I know it's a lot more money but, after low performance and replacing unreliable parts, it makes sense to me.
Pardon me but my karma just ran over your dogma.

Kern Dog

I'm not against a better mousetrap. I'm not afraid of pissing off the purists if the replacement equipment is superior.
Ma Mopar never put 4 wheel disc brakes on the B bodies, they never put 5 speed transmissions in them either.
The late model cars don't have much that we can easily swap in so we have some Mopars now with GM or Ford based transmissions, Ford brakes, Toyota alternators and who knows what else.


Kern Dog

The car wouldn't start this afternoon so I used a jumper wire to connect the wire terminals that lead to the ballast resistor, effectively bypassing it. It started right up. I reconnected the wire terminals to the ballast resistor and yes, it started up normally.
Maybe the main problem that I've had is in a poor connection? This is an aftermarket harness, new in 2013 from Evans Wiring. Maybe the terminals need to be better crimped or something. I'll dig in tomorrow or Wednesday.
I did go out for a drive and it ran fine. I actually got smiles and a thumbs up from a nice looking woman about 40-ish.
We like to think that the chicks like these cars but I rarely get attention from women when driving the car.

b5blue

70 year model weak point is the big red wire connector to the ignition switch at the column. It's an electrical choke point cuz the connector is thin metal. (I bypassed this using a "Allumacon" connector.)  :scratchchin: https://www.lowes.com/pd/Alumiconn-100-Pack-Purple-Al-Cu-Wire-Connectors/1003199382
Link to show item, you need not buy 100.

b5blue

A bottle of this has lasted 10 years and I've put this on every connection home/auto ever done. It works.
https://www.amazon.com/CAIG-LABORATORIES-D100L-25C-Contact-Cleaner/dp/B0000YH6F8  :2thumbs:

John_Kunkel

Quote from: Kern Dog on July 29, 2024, 09:13:40 PMthe main problem that I've had is in a poor connection? .


Timely post. This morning I clicked my remote to open my gate and...nothing. Opened the control box which has two 25-amp mini fuses, removed the first one and it's not blown, removed the second one and it, too, wasn't blown but when I reinstalled it the unit came alive and everything worked.

Connections that are exposed to the environment are subject to corrosion, that's why most all of the connectors on new cars are sealed with gaskets. For years I have taken to coating exposed connectors, like the spade connectors on your ballast, with silicon dielectric grease. Never thought to do that with the plug-in fuses I mentioned and it bit me in the ass.
Pardon me but my karma just ran over your dogma.

Kern Dog

My first computer controlled vehicle was an '84 Chevy truck. They used a really basic and primitive computer system but that was because carburetors were still being used. The truck had an underhood wire harness with a series of terminal ends that I believe GM called Weatherpackconnectors. They had rubber seals in the plastic terminals so that when they were connected, they could be dunked in water and still function. That concept seems to be in play in many other cars today. I don't know if GM was a pioneer in that but it was the first time that I noticed the design used.
When a connection is hidden within a sealed terminal end, you won't know if it is good or bad until it fails because from the outside, it may look fine.

Kern Dog

I have to admit that for most of my life, good fortune has come my way.
Situations that could have gone good or bad have usually gone good for me. Car accidents, my health, jobs I've had or didn't get...I sometimes feel like I've been blessed or somehow steered away from hardships that could have made my life more difficult.
I state that to explain that often times I throw things together and they just work.
Years later I do the same thing again and it fails. Since I had good luck before, I am confused and having trouble trying to figure what is wrong.
I never studied the specifics of the Mopar electronic ignition system. I've only recently learned that ballast resistors come in a wide range of resistance ratings and that the ECMs that are available must be matched to a proper ballast resistor to avoid failures.

Coil resis.jpeg

ECM ch 2.png

Somehow I avoided failures for a long time despite mixing and matching coils, ballasts, ECMs and distributors that may or may not have been compatible.
People that have encountered a lot of problems (if they are smart) probably learn ways around them by learning what they can. I want to do that.
In my opinion, the practice of just replacing parts to fix a problem is a not what a skilled person does.