Justwondering
Well-Known Member
How do I handle this problem of plug compatability?
JW
JW
1979 LeBaron Ignition Control Module
- Thread starter Justwondering
- Start date
80mirada
Well-Known Member
That module on the firewall is the voltage regulator. The ignition module, if equipped with that style would normally be on the passenger inner fender on FMJ bodies
Justwondering
Well-Known Member
Well, I do not in fact have an ignition module.
So I do not understand how the electrical works in this vehicle.
My manual clearly indicates that 1979 LeBaron has an ignition module.
I'm now totally confused.
What should I be looking at to understand how this lovely jewel works?
I have a crank, no start condition and am trying to figure it out.
This is really making me think it might be a starter issue since I've got a fully charged battery.
Although, the battery doesn't have the purchase date on it so I have no idea how old it is.
hmmmm
JW
So I do not understand how the electrical works in this vehicle.
My manual clearly indicates that 1979 LeBaron has an ignition module.
I'm now totally confused.
What should I be looking at to understand how this lovely jewel works?
I have a crank, no start condition and am trying to figure it out.
This is really making me think it might be a starter issue since I've got a fully charged battery.
Although, the battery doesn't have the purchase date on it so I have no idea how old it is.
hmmmm
JW
Justwondering
Well-Known Member
I'm thinking I should step back and test the spark from the coil?
Having not done that before, I'll have to read up on that process.
JW
Having not done that before, I'll have to read up on that process.
JW
Aspen500
Well-Known Member
If there is no ignition module on the passenger side fender well, you must have Electronic Spark Control (previously known as Lean Burn). The ignition module is in the computer attached to the air cleaner, and it also takes care of the spark advance functions. The distributor would have no vacuum or mechanical advance. Before I make a fool of myself by assuming,,,,, is there a computer module attached to the side of the air cleaner with a vacuum hose going to a vacuum transducer and a pair of ten pin(?) wiring connectors? It also would have a throttle position transducer and idle switch on the carb, along with a coolant temp sensor, not to be confused with the coolant temp sender for the gauge, and a single ballast resistor vs a dual ballast w/o ECS.
If it cranks but doesn't start, the starter is OK unless it cranks really slow and the battery checks good. As you said, check for spark and also fuel.
All you really need is a spark plug to test for spark. Put a plug wire (or coil wire) on the plug and ground the plug body (not to the battery terminal!) and crank the engine. To be sure you have GOOD spark, open the gap up to double or more and make sure it arcs the gap. I've seen where it'll jump the gap in the open air but won't spark when under compression. Basically, the spark gets "blown out" if it's weak.
If it cranks but doesn't start, the starter is OK unless it cranks really slow and the battery checks good. As you said, check for spark and also fuel.
All you really need is a spark plug to test for spark. Put a plug wire (or coil wire) on the plug and ground the plug body (not to the battery terminal!) and crank the engine. To be sure you have GOOD spark, open the gap up to double or more and make sure it arcs the gap. I've seen where it'll jump the gap in the open air but won't spark when under compression. Basically, the spark gets "blown out" if it's weak.
Last edited:
Justwondering
Well-Known Member
Has the rectangular box with the label 'Spark Control System'
JW
JW
Justwondering
Well-Known Member
This is beginning to sound like it the 79 LeBaron is more like my 87 Fifth Avenue.
JW
JW
Justwondering
Well-Known Member
I wonder if that means a 'y-pipe' would fit it?
JW
JW
Mikes5thAve
Well-Known Member
Yes on air cleaner computer except that the 5th has a newer generation of it.
Yes on y pipe.
Starter has nothing to do with spark.
Could be a bad coil. Tested like already been mentioned.
79 also has a ballast resistor but if it goes bad it'll start and stop the second you let go of the key.
Yes on y pipe.
Starter has nothing to do with spark.
Could be a bad coil. Tested like already been mentioned.
79 also has a ballast resistor but if it goes bad it'll start and stop the second you let go of the key.
If your car didn't already have the air cleaner mounted ignition computer (which you have), then the ignition module would be located here (which you don't have):
If you look at your inner fender, you will see a pair of screw indents (not holes) for the ignition module.
BudW
If you look at your inner fender, you will see a pair of screw indents (not holes) for the ignition module.
BudW
Justwondering
Well-Known Member
Thank the lord I don't have an iginition control module, for that is one ugly thing to put in your engine bay on the fender well.
(no offense to everyone who has one).
Darthcar reminded me that Dr. Lebaron used to occasionally whack his computer box when his car acted up.
So I first checked to make sure the plug was in solid for the computer.
Tried it. No Start.
Whacked it with a hammer a few times (carefully, but with firm intention), and still no start
HOWEVER
It sounds different now.
It now sounds like its starved rather than that is has no spark.
I have to make a 90 mile trip to the big city and will be back this afternoon.
If I don't get it started today, I wait til later this week. Cold front is coming in tonight and I have to go cover all the fig trees and plants I JUST PUT IN THE GROUND YESTERDAY... good grief.
JW
(no offense to everyone who has one).
Darthcar reminded me that Dr. Lebaron used to occasionally whack his computer box when his car acted up.
So I first checked to make sure the plug was in solid for the computer.
Tried it. No Start.
Whacked it with a hammer a few times (carefully, but with firm intention), and still no start
HOWEVER
It sounds different now.
It now sounds like its starved rather than that is has no spark.
I have to make a 90 mile trip to the big city and will be back this afternoon.
If I don't get it started today, I wait til later this week. Cold front is coming in tonight and I have to go cover all the fig trees and plants I JUST PUT IN THE GROUND YESTERDAY... good grief.
JW
The computer will give slightly better fuel mileage and driveability - but the (firewall mounted) ignition system is simpler, easier to diagnosis (when acting up) and (to some) more reliable.
The computer system is not easy to diagnosis and a person can't talk to it like most newer cars. When I was at a dealership, the fastest way was to have a box of "known good" parts and start replacing parts to see what fixed it. The official breakout boxes were a royal pain to use and sometimes didn't work (if not swiped from the shop...). I've used the official breakout boxes but is was so much easier to swap out a part and start the car (and repeat).
Computers were maybe the least likely item to give a problem.
The early computer systems used the engine ground for the return electrical circuit. On items like coolant temp sensors, most people like to use Teflon tape on the threads to prevent a coolant leak (if removed). Teflon tape works good for stopping leaks but also, unintended, does a good job of not grounding the sensor (ie: makes an open circuit). The later computer systems used their own return ground wire to the sensors and that problem got fixed.
A similar issue is the oxygen sensor. These cars used a single wire, I like to look at a new oxygen sensor and see if it has enough anti-seize compound on the threads. If not, I will add more (note: most new oxygen sensors do have a smidge of compound on them, but not enough - IMO). Anti-seize compound also does a poor job of allowing electricity to flow. The trick here is to make sure the metal gasket ring is good and dry before tightening the sensor.
Note: a lack of using sufficient anti-seize compound = you will never be able to remove that sensor again (at least not without drilling and re-tapping the threads).
Auto computers are similar to PC's. Bad data in = bad data out.
If the coolant temp sensor thinks it is -173 degrees outside, the engine will not run well, when it is actually 60 degrees - for example.
I am so glad that later computers we could ask the computer what is wrong and things got so much better after that.
Note: the computer gets bad rap - for most things it gets blamed for IS items used on cars decades before computers (leaking gasket(s), bad spark plugs, timing chain wear, bad gasoline (or fuel pump, carburetor, etc.) and so forth. It is ALWAYS best to check the basics before diving into a computer for the computer might not have anything to do with it (ie: check for spark, check for gasoline and so forth).
Just about the only thing that used for both pre/post computers is the ignition coil, pickup coil (in distributor) and wiring harness. Except for JustWondering, most people do not have a problem with the harness (and I doubt her rodents caught up with this car . . . yet).
BudW
The computer system is not easy to diagnosis and a person can't talk to it like most newer cars. When I was at a dealership, the fastest way was to have a box of "known good" parts and start replacing parts to see what fixed it. The official breakout boxes were a royal pain to use and sometimes didn't work (if not swiped from the shop...). I've used the official breakout boxes but is was so much easier to swap out a part and start the car (and repeat).
Computers were maybe the least likely item to give a problem.
The early computer systems used the engine ground for the return electrical circuit. On items like coolant temp sensors, most people like to use Teflon tape on the threads to prevent a coolant leak (if removed). Teflon tape works good for stopping leaks but also, unintended, does a good job of not grounding the sensor (ie: makes an open circuit). The later computer systems used their own return ground wire to the sensors and that problem got fixed.
A similar issue is the oxygen sensor. These cars used a single wire, I like to look at a new oxygen sensor and see if it has enough anti-seize compound on the threads. If not, I will add more (note: most new oxygen sensors do have a smidge of compound on them, but not enough - IMO). Anti-seize compound also does a poor job of allowing electricity to flow. The trick here is to make sure the metal gasket ring is good and dry before tightening the sensor.
Note: a lack of using sufficient anti-seize compound = you will never be able to remove that sensor again (at least not without drilling and re-tapping the threads).
Auto computers are similar to PC's. Bad data in = bad data out.
If the coolant temp sensor thinks it is -173 degrees outside, the engine will not run well, when it is actually 60 degrees - for example.
I am so glad that later computers we could ask the computer what is wrong and things got so much better after that.
Note: the computer gets bad rap - for most things it gets blamed for IS items used on cars decades before computers (leaking gasket(s), bad spark plugs, timing chain wear, bad gasoline (or fuel pump, carburetor, etc.) and so forth. It is ALWAYS best to check the basics before diving into a computer for the computer might not have anything to do with it (ie: check for spark, check for gasoline and so forth).
Just about the only thing that used for both pre/post computers is the ignition coil, pickup coil (in distributor) and wiring harness. Except for JustWondering, most people do not have a problem with the harness (and I doubt her rodents caught up with this car . . . yet).
BudW
Justwondering
Well-Known Member
Well I learned some basics today courtesy of Budw.
I learned that on batteries there is usually a sticker on one of the sides that has the month and year it was made.
There is also the scratch off date on the top of the battery and that is the date it was purchased.
So obvious now but I never knew about the sticker on the side of the battery.
An yes. The Lebaron battery was born in 6/09.
JW
And my personal thank you to Budw and Darthcar for my continued education and their patience with my ignorance of basics. Thanks gentlemen!
I learned that on batteries there is usually a sticker on one of the sides that has the month and year it was made.
There is also the scratch off date on the top of the battery and that is the date it was purchased.
So obvious now but I never knew about the sticker on the side of the battery.
An yes. The Lebaron battery was born in 6/09.
JW
And my personal thank you to Budw and Darthcar for my continued education and their patience with my ignorance of basics. Thanks gentlemen!
Justwondering
Well-Known Member
69- you are just the cutest thing!
Like I could remove a battery and not have scope creep.
The battery tray is sitting in a container of 3 gallons of pinesol for past 48 hours. Have another 12 hours to go. Slowly removing as much rust as possible. And had the typical rain delay.
On Saturday I try my new abrasive blaster I got for Christmas. The engine bay has rust and I can’t put it in pinesol. Lol
Soon as I get the rust off and some primer on it I’ll put the battery back in and try it.
JW
Like I could remove a battery and not have scope creep.
The battery tray is sitting in a container of 3 gallons of pinesol for past 48 hours. Have another 12 hours to go. Slowly removing as much rust as possible. And had the typical rain delay.
On Saturday I try my new abrasive blaster I got for Christmas. The engine bay has rust and I can’t put it in pinesol. Lol
Soon as I get the rust off and some primer on it I’ll put the battery back in and try it.
JW
Aspen500
Well-Known Member
LOL, sounds like something I'd do. Start off to do one thing but then the "while I'm at it", "might as well" kicks in.
Mikes5thAve
Well-Known Member
That's the way it always goes. My chrysler has been sitting for several years because of that. All because I wanted to get it to a car show that a member here runs (won't say names, he knows who he is). Yep [insert name here], it's still not done yet.
Aspen500
Well-Known Member
That's exactly how my "overhaul the fried trans and do a LITTLE body and paint touch up" turned into a 12 year project with the car torn down to a bare body shell and literally not a nut, bolt, or single piece went untouched. "Might as well", "while I'm in there", "if I do this, I'll have to do that (and that and that and that)" SNOWBALL, lol. In the end, worth every hour, every penny, and every drop of blood. I think it's a disease
Justwondering
Well-Known Member
Battery was not the problem.
Not the ballast resister.
Not the voltage regulator.
Not the starter.
Not the ground.
Not the ignition switch.
Not the plug wires.
Not the plugs.
Anybody want to guess the oh so simple solution to my starting issue?
Budw you can’t tell them just yet.
JW
Not the ballast resister.
Not the voltage regulator.
Not the starter.
Not the ground.
Not the ignition switch.
Not the plug wires.
Not the plugs.
Anybody want to guess the oh so simple solution to my starting issue?
Budw you can’t tell them just yet.
JW
