Help Please......No Spark

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6pk2goDemon

6pk2goDemon

Mopar Mod
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I believe it's time to ask for help from my FABO family. :happy8:

Fresh 340 in the Demon. Cranks great, but won't start. Seems to be no spark coming from the coil.

Here's what I think is info to tell you:

Mopar Chrome Box (New) - Tried it on another car & fired right up.
MSD Blaster Coil - Used, but also fired up on the other car.
Mopar Elec Distributor - Rebuilt by a Mopar racer
Ignition Switch (New)
Evans Wiring Harness (New)


Using a test light off the negative side of the coil:

Turn key to on - no light

Crank Engine - Steady light

Have been told that when cranking, the test light should be flashing and not steady on. Electrical problems are quite a challenge.......:-?

What to test next and how to do it ???? :dontknow:
 
Check the pickup in the distibutor. airgap should be about .008 and i think resistance is somewhere around 300 to 600.
 
yooper822 said:
I'd look at the ballast resistor. you should have a light in start and run!
Joe
Click to expand...


Thx Joe, Ballast is also new, forgot to mention that. Anything is possible even when new.......Tested ballast in "on" mode and power showed to both sides. Did not test in cranking mode....



camd64 said:
Check the pickup in the distibutor. airgap should be about .008 and i think resistance is somewhere around 300 to 600.
Click to expand...

Actually did try a different distributor and same thing. I assume checking the airgap is with a feeler gauge?? I have no idea how to test resistance.... no wonder it won't start...LOL



There has got to be something dumb that's being overlooked. Just so frustrating......urgh
 
6pk2goDemon said:
Thx Joe, Ballast is also new, forgot to mention that. Anything is possible even when new.......Tested ballast in "on" mode and power showed to both sides. Did not test in cranking mode....





Actually did try a different distributor and same thing. I assume checking the airgap is with a feeler gauge?? I have no idea how to test resistance.... no wonder it won't start...LOL



There has got to be something dumb that's being overlooked. Just so frustrating......urgh
Click to expand...
If using a feeler gauge, I think it has to be brass; non-metallic
 
i'm having the same issues 6pak. you may look under my thread in ignition NO SPARK
maybe between our 2 threads we can find our spark
terry
 
Terry, thx for the heads up on your thread. Electrical issues are not a strong suit over here.....very confusing. At least yours ran before....LOL

Maybe we'll race to see who gets their's figured out first. :sign5:



green1, :thumbup: I guess this could be checked but what are the odds that 2 distributors could be doing the same thing.........
 
i would see where spark ends. so like start at the plug end of the wires if none there keep moveing down the line. it sounds like you did that and i am thinkin something with the module. because shouldnt the light pulse during cranking? maby it is not grounded. i had the same kind of thing and it turned out to be the coil so i dont know for sure. but test the module more. maby it went bad between the two cars or could it be hooked up wrong?
 
touch your test light to the positive side of the coil and it should light up if you have power. Should be lit anytime the key is on whether in the run position or cranking. If it lights up the only 4 possibilities are a bad module, dist. problem, coil problem, or wiring problem somewhere in the circuit. If it don't light up your not getting power to the module. That could be a bad ignition switch or problem in the wiring harness and the first thing I'd look at is the bulkhead connector because they corrode up over time and are known to cause problems.

BTW: That old theory of touching the test light to the negative side and seeing it flash is kinda tricky cause even when cranking it flashes at least 250~300 times per minute (every time it fires on a cylinder) so it's real hard to tell if it's flashing or lit continuously.
 
Test light on pos side of coil in both run and crank should have light.

If that's good, hook up a timing light to see if you are getting anything down the wires.

Air gap on pickup should be about .008 and check it with a brass feeler gauge, no ferrous feelers. I had the gap spread way out on my Dart and it fired right up after checking everything out.

Tracy/Fishy is spot on in his stuff and the bulkhead is a trouble point.
 
positive side of the coil should have power with key on. Problem Is from your switch to the coil it sounds.
 
coil hooked up backwards??? battery have good voltage?? mopar electronic box,,you need at least 10.5 from the battery to fire it,,,,if less it wont fire,,,,
 
:wav:


Just an update. A friend came over to take a look this morning. Another set of eyes and thoughts were appreciated (thx Chuck), but after checking power everywhere we were still scratching our heads and lost..... There was power getting to the coil, but no power coming out. Gave up for the day with other stuff to do.

Late this afternoon....5 or so hours later, gave it another stare :scratch: and believe we found the problem. One of the wires for the new engine harness did not go into the bulkhead properly, so it was not making contact. This can't happen with an original Mopar harness because the wires are securely locked in place.

Fingers are crossed for a tomorrow start up. Wish me luck..........Might make it before '08 ends after all.

Thx for all the help.....stay tuned....LOL
 
so are you saying the replacement wiring plug doesnt lock in place??? that stinks
 
:-? disgust :-? :sad6:

Well.....that wasn't it. Turns out the plug in was for the alternator. Would have needed to find that eventually, but not today.....

Anyone have any marshmallows to share?

I think it's time for a Car-B-Que

Maybe next year this thing'l run...... :help:
 
6pk
ok i called don at fob systems ( ie 4secondsflat) told him of my problem of no spark out of coil, he feels its my pick up in the distributor. even though the msd box did fire when i tested it, it was just a test. the distributor needs to tell the msd box when to fire. don is a wizard on this stuff. give him a call at 541-942-5920. if no one answere's just keep calling back. visit his web sight try mopar distributors and it will bring up a couple of his sights.
good luck
terry
 
I Am Now Up And Running. Turns Out It Was The Pick Up In My Distributor. I Had A Msd Distributor And Wires As A Future Project But As Soon As I Installed It I Had A Strong Spark,
Terry
 
Terry, Congrats to you on getting your car running again. Hats off to you and the techs here that helped along the way.

We didn't work on the Demon today, too frustrating. :???: :confused:

I think after reading what fixed yours, we will take the distributor out of another running car and try that. We have tried 2 different distributors already, but they have been sitting around for awhile.

Thank you very much for your help......Best to you in '09. :thumblef:
 
Racerex1 said:
positive side of the coil should have power with key on. Problem Is from your switch to the coil it sounds.
Click to expand...

Yep....power on + is there, but how to check from the switch to the coil?



crackedback said:
Test light on pos side of coil in both run and crank should have light.

If that's good, hook up a timing light to see if you are getting anything down the wires.

Air gap on pickup should be about .008 and check it with a brass feeler gauge, no ferrous feelers. I had the gap spread way out on my Dart and it fired right up after checking everything out.

Tracy/Fishy is spot on in his stuff and the bulkhead is a trouble point.
Click to expand...


Will try the timing light hook up tomorrow....Thx




fishy68 said:
could be a bad ignition switch or problem in the wiring harness and the first thing I'd look at is the bulkhead connector because they corrode up over time and are known to cause problems.
Click to expand...


fishy68, If the bulkhead connector is corroded what do you recommend to rectify..... ? As posted earlier, the engine harness is new from Evans.....although the underdash harness is used from ebay. :dontknow:
 
Shoot I wish you lived closer. It's so hard to diagnose this stuff over the internet.

Can you have someone check power to the coil while the ignition switch is in the crank position? Forgive me if you've already tried this.
 
6pk2goDemon said:
Yep....power on + is there, but how to check from the switch to the coil?


fishy68, If the bulkhead connector is corroded what do you recommend to rectify..... ? As posted earlier, the engine harness is new from Evans.....although the underdash harness is used from ebay. :dontknow:
Click to expand...

If you have battery voltage at the positive side of the coil you don't need to trace the wiring from the coil back to the switch because it has to be ok. Also your bulkhead connector must be making contact or it wouldn't have battery voltage there. Sorry I overlooked that you said the harness is new. If that's the case the likelyhood of it being corroded is pretty low.

BTW: You really need a volt meter to check voltage to the coil cause a test light isn't a good instrument to be using because it will light with even 8 volts at the coil which isn't enough to fire. You really need a volt meter to make sure you have at least 12 volts at the positive side of the coil with the key on. While cranking the voltage may drop down to 11 volts but shouldn't go lower than that or there isn't enough voltage to make the coil fire.
 
6pak I just reread the entire thread to see if I missed anything and noticed in one post, the one where you said a buddy came over and you checked things and found the test light lights on both sides of the coil but still no spark. Could it be a bad coil? Do you have another to try?
 
Does it have power at the coil in both run and start key positions?
Check the power going into the box as well.
The ground on the box needs to be good. BTDT.

If all that stuff is good, then look at the magnetic pickup air gap.

If you have another known working distributor you can plug in, place the coil output wire so you can see it spark, turn on the key and give the shaft a spin. If it sparks you know where the issue lies.
 
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