It will start but won't run. [Solved. Wasn't ignition. :( ]

-
Corrupt_Reverend

Corrupt_Reverend

Well-Known Member
Joined
Jul 15, 2012
Messages
279
Reaction score
14
Location
California
'72 Dart 318, 904, stock ignition

Had my car die on the way to work yesterday. I thought I'd run out of gas, so I pushed to a gas station and filled up but now it seems that it's an ignition issue.

The car will fire while cranking, but quits when the key is in "run".

I checked for power at the ballast with a test light (with the key in "run" position) and I've got power. So I guess I can rule out the switch being the issue?

The coil has less than 100 miles on it and I haven't had any problems up until yesterday morning.

Any ideas on what to check next? I guess I'll pull the coil and have it tested but I don't think that's the problem.

Thanks in advance,

~Rev.
 
Did you check for power at 'both sides' of the ballast? Or just the supply wire? Or at the coil?
Check for power at the coil terminals when in 'run'. If the ballast isn't passing current, you'll have voltage when turned to 'start' but not 'run' and that would indicate a bad ballast.
If you have power at the coil in run and in start then it's not the ballast. The coil could be on the edge of bad, needing the increased start voltage to produce a spark but unable to do so in 'run', but it isn't that likely - still worth investigating if you have a spare. A low battery or one which is not performing perfectly (dead or shorted cell) could have a similar effect, so it's worth having tested as well. A battery issue would come with other issues too though, hard starts and slow cranking.

Do you have a multi meter that you can measure actual voltages with? Might help with other trouble shooting if it's not the ballast or the coil itself.
 
change the ballast...or actually...jump it and if runs ....shut off and change the ballast
 
I've got power at both sides of the ballast. My multimeter took a dive and I haven't replaced it yet.

I'll try jumping the resistor. If that doesn't work, I'll have the coil tested.

Thanks for the input so far! :)
 
same issue on mine.

but i had a ton of old parts and tricky wiring...

i still havent drove it far. but make sure your fuel lines (vapor LOCK ) are as far away as possible from (heat) i had mine close to the header - your carburetor base plate? is it aluminum might be causing fuel to boil if it gets too hot causing a shut off. i replaced the distributor RELOCTOR and the pick up coil. - cheap fix.

i also ended up gettin g a new ICM ... i switched out my ballast and that didn't fix it. i also switched my ignition relay and that didnt fix it. so far.... by switchin gthe ICM and reluctor with pick up coil , i got a new plastic carburetor base ( wont produce as much heat causing fuel to boil) and my fuel pump line was close to the header so i backed it off and that has solved my issue so far.

look at your bulk head for fried wires and or all your grounds....
 
Tried jumping across the resistor to no avail.

Gonna look up coil resistances and check that after I run and grab a new multimeter.
 
When your car died, did it quit suddenly or sputter and gradually die out? When trying to re-start, does the engine die again the instant you release the key from START to RUN, or does it sputter and gradually die out?

Stock coil resistance is around 1.5 ohms. When you measure this low a resistance, for accuracy first connect your meter leads together and see how much that reads in ohms or fractions of an ohm. Then measure the part, and subtract out what you read with the meter leads alone.
 
It is the ballast resistor. It's a few bucks so why not try the easy fix. I always carry an extra one in the glove box. The start but quits when the key is in run is the dead give away. I could be wrong though but I bet I'm not
 
It sputtered when it died initially, just like it had run out of gas.

But now, it just stops when the key goes to "run". No sputter at all.

I'm fairly certain that it's not the ballast resistor since jumping across it did nothing.

I've got power on both sides of the resistor, power @ the coil, and the coil is getting a firing pulse from the dizzy. I'm assuming the coil is firing while the key is turned to the start position since it does fire while cranking.

Oh, and Big-B, I'm in the central valley near Modesto.

I wasn't able to get a new multimeter today, but I did get mine working... kinda. It's indicating that the coil is toast, but the meter acts a bit funny so I don't fully trust the diag.
 
Your reasoning is pretty sound; some actual voltage readings on both sides of the ballast in START and RUN would help though; if you have some voltage drop in the IGN1 (RUN) position of the ignition switch, that would be hard to impossible to detect with a 12v test light, and that extra voltage drop could kill the ignition in RUN.

What kind of coil did you get? Just a generic box store type? I got a Pertronix Flamethrower (the 1.5 ohm coil primary version, not the 3 ohm) a few months back as a stock coil replacement, and it seems to be doing well. I trust that more than the box-store units of unknown origin and QC.

And what ballast do you have? There are a lot of the wrong ones that get put in.
 
Well, I tried running a wire straight to the resistor from the battery and still have the same problem.

Any chance it could be the ignition box kajigger? How would one test that?
 
Try jumping across the terminals of the resistor. My bet would be the resistor. If it does not run when you jump the resistor ITSELF, after releasing the key, then could be the condenser in the distributor. Do you have a point set/condenser distributor? But if it starts and then dies when you let go of the key, my bet would go with the ballast resistor. Like others have said, they are cheap, and VERY good insurance to have extras in the glove box, along with point set and condenser. DO NOT RUN LONG WITH A JUMPER WIRE ACROSS THE BALLAST RESISTOR. The caps are to let you know how critical that part is.
 
Ok, reread it again, and I see what you did. Now I will back off and say no more. Good luck, hope you get it going!
 
2 or 4 pin ballast? Assuming electronic ignition. If the ignition box is firing in crank it should be good. Your loosing ignition 1 for some reason. It could be ignition switch, bulk head connection, ballast, or the splice where the wires tie in for the ballast, voltage regulator, alternator and ignition module. I just went thru this with a brand new ignition switch and it was a bad switch. Until you can get some reliable resistance readings it will be hard to diagnose. You can have voltage indicated but the part your checking isn't able to carry the amp load.

Here are some basic diagrams to help out
http://www.forabodiesonly.com/mopar/showthread.php?t=238870

The color diagram will work, you just won't have the jumper for the blue on the terminals or the green going to the fifth pin on your module. For a two pin.
 
If it starts in the crank position of the ignition switch ,then dies when you release it, then you are loosing voltage somewhere.

I would disable the starter relay by unplugging the neutral safety wire so it doesn't turn over the starter with ignition switch in crank position and check voltages compared to the ignition switch in the run -released position including at the module connector.

With the resistor jumped temporarily for the test, you should have identical voltages in the crank versus the run position .
 
Same thing happened twice to me over the years. Check (clean contacts, make sure plug is tight) the big plug going into your ignition box. If this connnection seems fine, change the box.
 
Hmm. So i've been looking over all the diagrams and I'm kinda confused.

The PO converted my ignition to electronic. But the two wires coming out of the distributor go to the coil. That's how it was when I bought it and it's always worked and I never thought (or knew to) question it. All the diagrams I'm seeing show the dizzy wires going to the control box. What's up with this?

Oh, and to update: Definitely not the coil. While not a single parts store in my town will test them, there was one who had an ohm meter and they let me use it.

So now I know (or am pretty sure) it's not the coil or resistor.

I'm gonna try cleaning up the contacts on the ignition box and see how that goes but I'm still confused about the wiring mentioned above.
 
Is it a single coil ballast or a 2 coil (with 4 wires)?
 
Single coil ballast. And I just looked up pertronix instructions and they show the pickup hooked directly to the coil.

There's a little corrosion on the 5 pin thing. Mine appears to be factory original (small box on an L bracket with the roundish thing against the firewall (passenger side)). Or am I looking at the wrong part? The only other thing is the box on the driver side of the firewall and it has a two pin plug but I didn't think that was the ignition box thingie.

Edit: The thingie on the passenger side firewall has three pins. Apparently I can't count in triple digit heat.
 
So... I'm.. I'm retarded.

After cleaning up the contacts and hooking everything up, I tried to start it again to no avail.

Then I got to thinking that I've been using ether to start it. Now, in my defence, I could have sworn it started of it's own volition before I had it toed to my house. It was on that assumption that I stacked another assumption that it only needed the ether because the battery was a bit low and it wasn't cranking very hard.

Well, after trying to start it this last time, I decided to give the exhaust pipe a good whiff... and I smelled no gas. #-o

Pulled the carb supply line and cranked it... no gas.

Pulled the pump feed and put it in a gas can and cranked it... no gas.

:banghead:

Yep. My fuel pump gave up the ghost.

Big thanks to everyone who helped chase the problem that didn't exist though. haha

In the future, when I have an issue, I need to think of what I think is wrong... and then investigate something else entirely.
 
You must log in or register to reply here.
-

Back
Top