Cranks but doesn't fire!

79' Dodge B300 Extended Cargo Van
LA360 V8 2bbl
A727 transmission

I'm back unfortunately!
I drove my van over to a neighbors this morning, started just fine and ran great on the way there but it took longer than usual to start again before heading back home but it eventually fired up and ran great on the way home! I got home and had it parked for a few hours and I went out there to move it and now it won't start at all! It cranks really well but no ignition! Yes it has fuel and I took the air cleaner off to see the fuel squirt into the barrels...

If some of you remember me I was here a few weeks ago dealing with an overcharging issue which I bypassed and still running the bypass wire! I haven't had time to figure out the cause of the overcharging issue yet, not sure if it's related to the no start problem I'm having now but thought I'd mention it!

The last electrical issue I noticed with it was the backup lights weren't coming on! I'm not certain but it's the neutral safety switch that engages the backup lights when put in reverse correct? Could a bad neutral safety switch cause it not to start?

"Could a bad neutral safety switch cause it not to start?" It would not crank or turn over at all if there is no neutral safety switch contact. Have you checked for spark?

neutral saftey as said above would stop cranking.

as for the bypass, if you ran it to the wrong side of the ballast, you could have burned up the coil as it shouldn't take that many volts.

but also as said above, check for spark before throwing parts at it.

the odd part is that it ran and wasn't a problem till you tried to restart. so I would also be checking for power at the various spots you messed with as a starting point.
you might also put it in run and then jump the relay for the starter and see if it fires up, in which case it would be the start circuit to chase down.

As mentioned, check for spark.
Been a minute since I had one that old but were ballast resistors an issue in '79?


Tim

If it has a ballast, it would be bypassed in start. It would start then as soon as you let go of the key it would die.

Assuming the system is wired properly.

During start mode the electrical system is at it's most loaded down state, not uprising that any marginal part of the ignition system would not work then, but work in run.

Without any troubleshooting info, hard to say what failed.

I ran the bypass to both sides of the coil...

Well... I just did a spark test from the wire coming out of the coil to the distributor and there's no spark! I unplugged it from the distributor and ran a jumper wire from that end to a ground and nothing! So I guess the coil is fried! It's actually the original chrysler coil so maybe it was just time for it to fail or could it be that the bypass to the ballast did something??? I'd hate to buy another coil just to fry that one as well!

then you killed the coil with the bypass.
the ballast resister takes the voltage down in run to about 8 volts.
by running 12 volts to it you burned it out.

there are 12 volt coils, so you can replace it with one of those, but in the future recheck which side of the ballast has 12 volts first. and only put 12 volts to that side.

Have you checked for power to the positive side of the coil?

Sorry, I meant ballast resistor not coil!
I ran a bypass wire from the battery to both sides of the ballast resistor (pictured) due to the overcharging issue....

Yes, I just did! There's 11.9 volts going to the positive side of the coil with the key in the ON position... and incase it matters there's 11.7 volts at the negative side of the coil...

the coil cannot run on 12 volts for long or it will die.
in run you should only have about 8 volts going to it.
I don't remember how the 4 post ballast works, but you have to only jumper the side that reads 12 volts with the key in run, not both sides.
so remove your jumpers and check voltages again to see which side reads 8 vs 12 and only jumper the 12 volt side.
or you will be getting another new coil.

or you can eliminate the ballast and use a 12 volt coil.

Here's the thing about the bypass I installed... I ran a wire from the battery to a switch and from the switch to both sides of the ballast so that I wouldn't have to remove the bypass from the resistor every time. The readings I posted are without the bypass engaged!

My advice is get rid of the add ons you did and go back to factory wiring. It worked for years and there is no reason for it not to work now. Just a suggestion.

You guys are jumping into an ongoing mess with this van.

The reason for the bypass he talks about is because there was a voltage drop between the key and the ballast resistor. The by pass was suppose to be a temporary thing until he had time to chase down the reason for the voltage drop. Apparently since the van has been starting he felt there was no need to look into the cause of his original problem, its been a few months. There has also been a big over charging issue with this van, I don't remember if that got resolved or not. Then there was a fuel pump dumping fuel into the oil pan. I believe he got that changed, but I'm unsure if he ever changed the oil.

The way the bypass has been wired, the ballast is still fully functional. The bypass eliminated all the wiring connections on the van between the key switch and the ballast, it has done nothing else..

So he is back looking for another cheap temporary fix to get it running until the next time it won't start. Not that most of us have not been in that position before, a time or two.

This is going to sound dumb, but look at the position the rotor is pointing at on the distributor, then crank the motor just a little, and see if the rotor has turned at all. The motor may have a bad timing chain. If the rotor is turning, pull # 1 spark plug out of the cylinder and see if there is compression while the motor is cranking over. .if you have compression, see if you can bump the motor so that the timing marks are lined up at "0" and look to see if the rotor is pointing at the place on the distributor cap where the wire to cylinder #1 is. If its off 1 spot, the timing chain may have slipped and it needs to be replaced. If the rotor is pointing at the place the #1 wire is, then move on.

If you have power to the coil, the problem is in the ignition system, It could be as easy as a bad coil wire from the coil to the distributor, a bad coil, or a fried electronic ignition part. The coil wire, and then the coil are the cheapest places to start. If you have something there that runs that has a similar coil wire, or coil, you could swap them over onto the van (one at a time please) and see if the van will start. If it starts, replace which ever one was bad with a new one.

If that doesn't work, your going to have to remind us what ignition system is on your van (it may or may not be original to the can), before we can move forward from here.

i ran into a bad coil wire last fall on my charger. it would sometimes start easy, and sometimes take forever to start. after it started, it ran good.
the problem turned out to be the brass connector that attaches to the wire, then plugs into the coil.
it had been a bad connection for a while, as the brass had a bunch of burn marks and pits, and had actually started to melt through the rubber coil boot on the bottom. [coil is mounted horizontally, thus, the bottom of the boot couldn't be seen.]
new coil wire and all has been well since.

I can't! There's a reason for the bypass... I don't have any other 'add-on's' other than that!
I started another thread a couple of months ago about it.
I was(still) having an overcharging issue with van and I still haven't had time to find that problem so as suggest I installed the bypass so I could drive it!
Believe me, I don't want all these extra little things on my van! I want to fix the issues so that it goes back to working the way the factory intended!

The reason I still haven't address the underlying issues for the bypass is because my daily driver as an S10 which I was replacing the clutch in which I finally finished and have been driving...
I was driving the van because that's my backup vehicle but I'd still like to keep chipping away at it to get it fixed properly because I know I'll need to drive it again very soon! I still have more work to do to my truck so I'd like to get the van properly fixed...
I thought we already identified the problem was the coil at the beginning of this thread!
No spark coming out of the sparkplug wires and there's 11.9 volts going to the coil at the positive side and that number has nothing to do with the bypass because the bypass isn't engaged!

Edit:
I did end up changing the oil twice and I probably didn't even have too because there wasn't much fuel that made it down into the cylinders if any but I still changed it to be safe!

As mentioned above by 'Andrewh' I may have fried the coil running the bypass to both sides of the resistor! One side goes to the ignition control module and the other side goes to the coil! I have now removed the bypass from the coil side! I have a new coil waiting for my at the UPS store so when I'm able to get to town I'll install it and see what happens! I'm sure it'll work fine again but for how long is the question? I don't want to keep frying components so obviously I'll be going back to the "overcharging issue" thread I started months ago to pick up where I left off and actually fix the problem!

Andrewh! You are 100% correct!
I just installed the new coil and it fires up and runs great!
The problem was exactly what you said it was! I ran the bypass to both sides of the resistor when I should've only ran it to the side that goes to the ignition control module! So one side of the resistor goes to the coil directly and one side goes to the ignition control module! I removed the bypass from the coil side and now the coil is getting 8.5volts!
Thank you sir for all your help!
I'll still be back to figure out the overcharging issue when I have time but for now the van is drivable again!

There are 12 volt coils, and there are 12 volt coils.

Coils normally marked as 12 volt are made to have a resistor in front of them. Other 12 volt coils have the resistor built into the coil.

Rambler was one of the few that used a coil that had the resistor built in.

glad you got it up and running.

Thanks! Not sure if you've been keeping up with the old thread I started a couple of months ago about the overcharging issue but after installing the new coil the voltage has dropped down to normal levels and it's not overcharging anymore!!!! I'm talking between 13.2 - 14.2 volts from idle to acceleration!!!!
Could it be the coil or a connection on the coil was the issue and the reason it was overcharging??? I don't think it's a coincidence but maybe it is...

not likely.
it is down stream of the splice that supplies power to the vr sensing line.
more likely some wiring you messed with, a connector or whatever got connected better.
till you find it, I would continue the bypass, because a good bounce, or road vibration could make it go bad again, and you don't want to see a spike while driving.
had one go out like that while driving and it vaporized 2 inches of copper and about 5 inches of insulation under the dash. showed something crazy like 100 volts output.

"had one go out like that while driving and it vaporized 2 inches of copper and about 5 inches of insulation under the dash. showed something crazy like 100 volts output."


and i'll just kinda' guess all the "magic smoke" escaped, causing a great deal of consternation..............

have you Ohmed out the coil? possible internal short pulling the Voltage down
You could always reinstall to see if the issue recurs But sometimes at the end of a long journey it's best to leave things alone

the smoke pouring out from under the dash at 55 with all the windows down was quite impressive, I will say.
I don't think I have ever pulled over that fast before and jumped out of a car.

the fact it still was running and everything seemed to be working was amazing.
I was near some small town in podunk and a garage was on main street and they offered to take a look, since the car wasn't on fire. lol.

i'll bet the guy that come up with the invention to "re-install magic smoke" will make a fortune !

here ya go, Do be aware there are different sizes depending on the amount needed. The first pic shows the injector kit . Also there are newer versions that are claimed not to be as good as the original. Last verify country of origin as there are some knockoffs that may work or require a complete rewire after using BTDT 🧨🎆🎉💥💥👎🏻🤫🤣🤣🤣🚀

No good.
These are for positive earth systems.

Perfectly fine if you turn the container upside down before injecting the smoke. Doing so reverses the electrons polarity 🤫🤣

i always knew the "magic smoke" solution was out there, but i have never seen the tool used to install it.