Coil problem?

Aspen500

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Kind of sad when a n old original works fine and a new replacement fails multiple times. I had the same problem with the neutral start switch. Two parts store replacements within a year failed. My dad had 3 or 4 originals from the 1960's in his stash and that's what's in there today, a 50 year old switch. Seven or so years later, it still works as designed.
 

BudW

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If your car has a computer mounted on the air cleaner, then it might not have a ballast resistor on the firewall.

Chrysler ignition coils do not run at 12 volts, except at startup. You "can" run 12 v (or battery voltage) to get a hotter spark - but ignition coil lifespan will be greatly shortened (like down to minutes, if not down to seconds) instead of decades. That is not counting for the fact of "made in China", which is a discussion for another day.

Chrysler ignition coils do not go bad that often. If at a place to acquire spare parts, always grab an used Chrysler ignition coil and stash away in the garage (along with a used voltage regulator, ballast resistor, Ignition module, etc.).
BudW
 

SharkHead

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So far it is running fine on the Mopar coil I obtained in Salvage- is there an easy way to see if the coil is being over driven?
 

BudW

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is there an easy way to see if the coil is being over driven?
I am not sure what you are asking for her, exactly. Chrysler ignition coils are the same, sense '60ish until mid to late '90's (points, electronic ignition or air cleaner mounted computer controlled).

Ignition coils are filled with oil to help dissipate heat - so if you see a coil leaking oil or cracked - I wouldn't use it (limited lifespan remaining).
(Any/all) Ignition coils are lazy and will only put out the voltage needed to fire the spark plugs. Example would be if spark plug gap is set close (say 0.015 inch/0.38 mm) it might only take say 10,000 volts to fire, when at idle. If spark plugs are gaped too wide, say 0.045 inch (1.14 mm) then it might take say 50,000 volts to fire the plugs when engine is under a load. It takes more voltage to fire a wider gap and it takes more voltage to fire when cylinder pressure is higher (when under a load or acceleration).
Note: All FMJ vehicles should have spark plugs gaped at 0.030 inch (0.76 mm).

Going by memory, I think the Chrysler ignition coil will fire up to (an average of) 44-45,000 volts before it cuts out - but don't quote me on that number.

A wider gap on spark plugs will provide a hotter spark - but it does wear out the plugs a bit faster and does require more voltage from the ignition coil. If you have a car with a weaker ignition coil (misfiring while on the road, or whatever), you can make the plug gaps less and generally able to at least get to your destination. Having a hotter or colder spark doesn't mean there will be much (if any) difference on how the car feels, drives or even with "timed trial events".

For my customers cars, I have always set plug gap at factory specifications (again, for FMJ's is 0.030" (0.76 mm)).
For my personal cars, i have always set the plug gap at 0.005" more (or to 0.035" (0.89 mm)) and have never had any issues - for the ignition system has enough overhead.
Going to 0.040 inch gap might be too much and could be a source of a misfire under a load - which would happen if the ignition coil could not produce enough voltage to fire the spark plug (under pressure). In this case, when you decrease the load a bit, the misfire would cease but as you increase the load and misfire would re-occur. You want to leave enough ignition overhead to compensate for plug wear or other conditions that would increase the required ignition voltage.
BudW
 

SharkHead

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Thx BudW - that clarifies some things for me-as good as it is running with an original Mopar I have to assume that the new replacement coils that went bad were just pure junk - hard to believe they can sell this stuff!
 

BudW

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It's the "Made in China, baby" fad . . . I guess.

I always look at where a part was made. Replacement electronic parts (ie: voltage regulators, ignition modules, and so forth) from that location are junk, OR you could say the paper box is worth more than the contents. It is sad to see where a 40 year old used part is worth more than a brand new part is - but it is what it is.
hard to believe they can sell this stuff!
I would use a different word than "stuff", but I also need to keep the forums rating at PG.

BudW
 

Aspen500

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Yep, made in China. Yesterday we had a 2010 Lincoln MKZ in the shop with the A/C inop. Actual static pressure was 100 psi yet on the scanner, the PCM was seeing zero psi, unplug the cycling switch and it shows 500 psi (circuit good). So, change the cycling switch. Now it shows 4 psi. Get a another one from next door (Advance Auto Parts). That one showed 8 psi. Dig through our "test" parts and find an old original Ford one we took off when replacing a line (with Ford), that came with one on it already, so we saved the good old one. Screwed it on, pressure shows 100 psi on the scanner and the A/C worked. Two Chinese pieces of "stuff", bad right out of the box, old original worked perfect.
 

Mikes5thAve

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be careful what you read about leanburn because technically that's a different generation of computer then what an 89 has and not everything works the same.
I've never heard of the over voltage bit but it's 30 year old electronic parts so it could fail in any number of ways.
I've never tried with those later systems but I'd guess you could check the voltage at the coil to get an idea of what's going on.
 

Ele115

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Stuff in junkyards is usually better than parts stores now IF it hasn't been replaced before the car was scrapped and you verify that the part is not worn out. Pretty sad.
 

Ele115

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Ah, I missed the part about the car still having lean burn :oops: Carquest and Advance Auto are one and the same company. IMO, Advance ruined Carquest when they bought it, but that's for a different thread.

Might be $40 for a real Mopar coil but it'll cost less with way less headaches and "what if it dies somewhere" syndrome in the long run. From what we see at work, Mopar has WAY more parts that say "Made in USA" than any other car company, especially GM parts which more often than not say "Made in China". I'm talking factory dealer parts, not aftermarket from a parts store. Guess what? Made in China GM parts are just about as junk as the Chinese aftermarket parts are. What I mean is, hopefully the Mopar coil is Made in USA.
Advance is garbage. They bought Car Quest's reputation and their parts inventory. Their parts were mostly OK, but once they burned through the parts, there was nothing left to run on. The Car Quest parts were gone, most of the original decent CQ employees had jumped ship, and the reputation was as shitty as ever.
 

Mikes5thAve

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carquest here still has decent parts but being in Canada they could very well be using a different supply chain.
 

Aspen500

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The one Carquest store here that remained CQ is good, and the parts are better than what the Advance stores sell now. Seems like Advance buys parts from the vendors with the lowest bid and, they're lower priced for a reason. It's like hiring a contractor. You NEVER hire the one with the lowest quote. The Advance next to work still has very good people working there. In other words, when you say what part you need, they know what that part is AND how to look it up vs an "uhhhhhhhhh, we might be able to get struts from the warehouse" type that wouldn't know a starter from their backside.
 

Mikes5thAve

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I've only ever had a problem with two advance parts, a heater core and a rad and in both cases it was because they weren't as listed on their site and in both cases it was more of the manufacturer changing the part then the store.
 

AJ/FormS

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If anyone ever wants a killer reliable coil, try the big square-top Accel Supercoil with it's matching resistor, or whatever it takes to get it to draw less than 8volts when fully warmed up. Mine was new in about 2002. I mounted mine on the passenger side apron near the shock, on it's side, studs down, with a really long coilwire.
 

SharkHead

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be careful what you read about leanburn because technically that's a different generation of computer then what an 89 has and not everything works the same.
I've never heard of the over voltage bit but it's 30 year old electronic parts so it could fail in any number of ways.
I've never tried with those later systems but I'd guess you could check the voltage at the coil to get an idea of what's going on.

be careful what you read about leanburn because technically that's a different generation of computer then what an 89 has and not everything works the same.
I've never heard of the over voltage bit but it's 30 year old electronic parts so it could fail in any number of ways.
I've never tried with those later systems but I'd guess you could check the voltage at the coil to get an idea of what's going on.
Can you clue me in on how to test the coil voltage?
 

Aspen500

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Hook one test lead to battery ground and the other to the positive primary terminal on the coil. There will be a voltage reading in key on, crank and engine running. The important one is what it's getting while running.
 

Aspen500

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All depends what coil is on there. If it's one that doesn't need an external resistor, battery voltage is fine. If it's one that does need a resistor, the reading should be around 7 to 8 volts running. Either way will work, as long as the coil and circuit are matched to each other.
 

SharkHead

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Well the blinkers seem to flash really fast and I have had problems with coil burnout--I read somewhere that the voltage on the '89 is controlled through the board-there is no external ballast resistor on this model car.
 
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