225 having some trouble firing up

[Sully1190]

Ok, hombres.

A couple of weeks ago, I spotted a car that me and my wife absolutely fell in love with. It's a 74 Gold Duster. Needs some work. Needs a new paint motif, but as for the bones of the car, the style and such, it's perfect, and we're ready to have this felluh up and running as a daily driver.

I knew it had some electrical problems from the start. (There was a jumper wire going from the battery to the coil used to start it.) But that's all part of the adventure, right? I love working on things, and my father knows a decent amount about cars, mechanically, so I was stoked to have a project I could work on with him. I cranked it up no less than 5 times at the guy's place before I bought it. It did so perfectly. I hop in, to start the 4 hour drive home (admittedly, that was a bit of an optimistic goal... but I am a dreamer.)

It drove two hours like a goddess, but at about the point we hit Hattiesburg... She went dead. Straight out. Coasted over, and wouldn't start up again. Didn't overheat. Would occasionally turn over, and occasionally just make a clicking sound when the key engaged... Well, yay.

((Fast forward a few weeks))

Yesterday was the day of the most progress. We replaced the starter relay (which now, we realize may not have been bad). We traced out a wiring problem or so (along with alot of redundant wires that some pinhead had put in...). As for the ignition, the connection was bad at the firewall for the wire that delivered all the juice to the column and such, so we fixed that, and now, every time you hit the key she starts turning over perfectly.

We had already feared that the reason it wasn't starting up, and the reason that we weren't getting fire from the coil, was that the coil had burnt up from where it had been bypassed. There was also the absolutely perplexing matter that both sides of the coil are hot, which, as far as our automotive knowledge "just ain't right." We call some people to re-affirm our suspicions, and a guy tells us that means that the coil is indeed burnt up. So we replace it (and the fuel pump which had begun leaking earlier in the day). But here's the thing. As soon as I click the key forward to let the juice start flowing, my padre sticks the tester to the coil, and both sides still light up. Now, I know we didn't burn this coil up in 2 seconds just from turning the key, without even trying to start it. Still no fire. The two wires that go to the distributor (which have a disconnect in the middle) also read hot. Which is odd. Why would you send two small hot wires? Somebody told us it might be the distributor, however, the problem is, these are the wires going TO the distributor. If they're not both supposed to be hot, then there's something else going on here, right?

I heard mention in other threads that similar problems can be caused by the ballast resistor. Since I don't have my father handy, that's the one on the driver's side by the computer, right? (We have reason to believe that one might be bad, actually... but we didn't think it could affect the car in this way). Your help of any kind is greatly appreciated. It's getting plenty of fuel. It's not a gas issue. It's electrical.

 

[cudamark]

I think you're going to need a factory service manual to trace your electrical problem. You should not have battery juice at the distributor. The circuit is just a loop through the pickup coil that the module uses to decide when to discharge the spark.

 

[Bulldozer]

well here is a diagram of the electronic ignition system.if you can rule out any of these components as bad or less than adequate, then im pretty sure that it would have to be somewhere between the ignition switch and the junction box. i have heard of ignition switches going bad and playing havock and causing wierd things to happen.just a thought...

 

[powerwagonpaul]

most likley you burned up the coil bypassing the ballast resistor on the way home. after you replaced it, you still need to track down WHY it neded to be "hot wired" in the first place. as for both coil terminals being "hot" i presume you mean 12 volts on both sides. that is just fine, remember that the coil is just that, not a resistor. you wont drop voltage across it.

 

[Sully1190]

most likley you burned up the coil bypassing the ballast resistor on the way home. after you replaced it, you still need to track down WHY it neded to be "hot wired" in the first place. as for both coil terminals being "hot" i presume you mean 12 volts on both sides. that is just fine, remember that the coil is just that, not a resistor. you wont drop voltage across it.

It was bypassed because of the bad connection. It couldn't get enough juice through that plug, so they just... "ran some extra." or something stupid.

You're saying that it's a non-issue for the coil to light up on both posts? I thought one was just a ground.

Thanks for all the help people! I'll start trying to follow up on those leads and keep you all posted.

 

[powerwagonpaul]

It was bypassed because of the bad connection. It couldn't get enough juice through that plug, so they just... "ran some extra." or something stupid.

You're saying that it's a non-issue for the coil to light up on both posts? I thought one was just a ground.

Thanks for all the help people! I'll start trying to follow up on those leads and keep you all posted.

it will ground thru the ECU when told to by the pickup in the dizzy. on points dizzy it will ground thru the points themselves.

 

[Sully1190]

it will ground thru the ECU when told to by the pickup in the dizzy. on points dizzy it will ground thru the points themselves.

Ah! I think I understand it all now.

So the distributor should be causing it to alternate between hot and ground, correct? Problem is, it doesn't alternate at all. It just stays full-hot when the engine is trying to crank. Unless I'm misunderstanding, which is entirely possible, because I don't profess to be the most inclined person in the world on these parts, that might mean that the distributor isn't turning to hit a point? Which would explain why we're not getting a spark from the plug wires?

Or, would the problem more likely lie in this ECU?

 

[TrailBeast]

Very likely just a ballast resistor and an alternator, from what the symtoms are.
You drove away and a while into the trip the battery went dead from no charging.
Coil could have overheated but start with the ballast and the charging system first.
If you have no spark still then replace the coil.
All these parts are cheap relatively.

 

[Sully1190]

Very likely just a ballast resistor and an alternator, from what the symtoms are.
You drove away and a while into the trip the battery went dead from no charging.
Coil could have overheated but start with the ballast and the charging system first.
If you have no spark still then replace the coil.
All these parts are cheap relatively.

I think it was less of the alternator and more of it being a bad battery. We had to replace it. It lasted a day or so, but when it started getting cooler, we couldn't even get it to hold anything when on charge.

But I will still check on the alternator.



Back to the ECU, is that the same thing as this: http://www.autozone.com/autozone/parts/1974-Plymouth-Duster/Ignition-Control-Module/_/N-ioxm9Z9n80t?

I heard mention on another automotive site that you can have these "tested" at a parts store. If so, I will take it on in.

Looking into buying a repair manual and a few needed parts.




To be clear, before when I was referring to the wires that went to the distributor, I was referring to the ones seen here: http://www.autozone.com/autozone/pa...80u?counter=0&itemIdentifier=768499_0_0_17452. Both sides are hot.

 

[Sully1190]

Check to see if there is anything oozing from behind the ECU controll box. These controllers are notorious for overheating and burning out. A good indication that this might have happened is the epoxy that seals the ECU melting and oozing out from behind. Good Luck!!!!

Aha.

Mine has ooze.

I love it when things begin to make sense.

I'm going to assume that this could have potentially happened from some of the hot wiring that had been done?

 

[powerwagonpaul]

Ah! I think I understand it all now.

So the distributor should be causing it to alternate between hot and ground, correct? Problem is, it doesn't alternate at all. It just stays full-hot when the engine is trying to crank. Unless I'm misunderstanding, which is entirely possible, because I don't profess to be the most inclined person in the world on these parts, that might mean that the distributor isn't turning to hit a point? Which would explain why we're not getting a spark from the plug wires?

Or, would the problem more likely lie in this ECU?

the way an ignition coil works is rather simple when you have a basic understanding of electricity: when electricity flows it causes a magnetic field, this field can be imparted to another wire in close proximity causing electricity. the coil is actualy TWO coils, the primary that the ignition is hooked to, and the secondary that fires the plugs. when the primary is grounded (thru the ECU or points) current can flow, creating current in the secondary and firing the plugs.
it seems to me that your coil fried and it needs replaced, perhaps the balast went bad and they just ran a hotwire to the coil because they didnt know about the balast resistor or didnt have one. replace both the balast and the coil. if that dosnt solve the problem try a new ECU.
use the diagram that 73AbodEE gave you and make sure all the wireing is good. make sure you have batt + voltage at the balast reststor on one side only.

 

[Sully1190]

the way an ignition coil works is rather simple when you have a basic understanding of electricity: when electricity flows it causes a magnetic field, this field can be imparted to another wire in close proximity causing electricity. the coil is actualy TWO coils, the primary that the ignition is hooked to, and the secondary that fires the plugs. when the primary is grounded (thru the ECU or points) current can flow, creating current in the secondary and firing the plugs.
it seems to me that your coil fried and it needs replaced, perhaps the balast went bad and they just ran a hotwire to the coil because they didnt know about the balast resistor or didnt have one. replace both the balast and the coil. if that dosnt solve the problem try a new ECU.
use the diagram that 73AbodEE gave you and make sure all the wireing is good. make sure you have batt + voltage at the balast reststor on one side only.

As I said, I have already replaced the coil, but, thanks for the heads up on the ECU, it led me to the stuff I needed. I am 99% certain it's bad. I'll replace it and the balast and hopefully then I'll be ready to roll! Thanks so much to you and everybody for the help though. I know I'm a newb with this stuff, but it means alot to have a supportive community and information source to help you out when you need it, yaknow?

 

[Bulldozer]

and one more thing that i can add. im pretty sure this isnt the case with you as you have had what appears to be a good spark,but make sure the connectors on the ballast are plugged in correctly.sometimes the tabs get broken off and they can get reversed. they can be flipped around, and the engine will fire, but will miss under load and you will have a very weak spark . if you pull off one of the wires at the cap while its running,you should have a very bright orange/blue spark and be able to hold the wire a good 1/2 inch away from the cap and it should throw a good spark.if the ballast connectors are reversed ,and you pull a wire off you will see virtually no spark at all but when it is in the cap,it will still fire. believe me,i found out the hard way after replacing every part of my ignition on my charger chasing a weak/no spark/misfire demon, i found the previous owner had reversed one of the ballast connectors . make sure each component of your ignition circuit is in good working order, as all the parts are really pretty cheap. .i went through a box of old parts (but still good)replacing one thing at a time,even the distributor. and while changing out the ballast(which seems to be the most popular culprit and the weakest link) i discovered the problem.

 

[Bulldozer]

just like sully1190 said ,there is a definate reason someone "hotwired" it and that in turn could have fried your ecu or your coil or the ballast or even the pick up in the distributor, or a combination of such, if it got hot enough.these pieces should never be bypassed because they have their own voltage/ohms to maintian to work properly. maybe it worked for a while but you start frying stuff until it eventually just stops working.

 

[Sully1190]

Went down today, replaced the ballast, the ICM, and the fuel pump (it had been leaking). It cranked up like a pro. Runs great. Next on the list, hitting up another wiring issue or so (headlights and compressor), and then it'll be paint time. Thanks for all the help guys. Couldn't have done it without you.

 

[cudajim]

"the way an ignition coil works is rather simple when you have a basic understanding of electricity: when electricity flows it causes a magnetic field, this field can be imparted to another wire in close proximity causing electricity. the coil is actualy TWO coils, the primary that the ignition is hooked to, and the secondary that fires the plugs. when the primary is grounded (thru the ECU or points) current can flow, creating current in the secondary and firing the plugs.
it seems to me that your coil fried and it needs replaced, perhaps the balast went bad and they just ran a hotwire to the coil because they didnt know about the balast resistor or didnt have one. replace both the balast and the coil. if that dosnt solve the problem try a new ECU.
use the diagram that 73AbodEE gave you and make sure all the wireing is good. make sure you have batt + voltage at the balast reststor on one side only. "

Actually the way it works is that the field builds up then gets temporarily "grounded" which causes an inductive kickback which gets transferred to the secondary coil which builds up the voltage resulting in a high-voltage spark.