Hate to start another thread ... but.. help !

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RPM

RPM

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Ok so I have cruised through many topics on this subject.... and still am kinda at a loss. Maybe someone with some electrical knowledge can lead me down the right path ..... please !

Heres the scoop.....

My car suddenly developed a issue where it will just be running fine and then die... kaput. Saw the coil was leaking pretty bad.
Replaced coil.
Same problem still exists.
Find I can start the car in park / neutral with no problems. Fires right up.
Runs and idles pretty good in park/neutral.. but have noticed a slight hiccup in the idle. So now I put the car in gear drive/reverse and it will idle about 10 seconds and then suddenly die. Kaput. Put car back up in park... hit the key an it fires right back up. Put car back in gear... dies. I have eliminated any fuel issues. So I started using what little electrical knowledge I have and found that the battery was pretty much junk... hey.. it was 10 years old. So installed new battery. Still has same problem. (didnt think that would fix it.. but hey... ) Ok so battery running proper voltage. Alternator at proper voltage. Check voltage at coil.... blaaahhhh.... 4 volts... and lower. Hmmm.... ok... for giggles I switched to another known good coil thinking my new msd one is junk. Nope... same ... 4 volts or less. Thats even on start up folks. So... what the heck ? I changed out ignition boxes (just standard chrysler black box. The alternator is new, battery is new, regulator is new, and the ballast is like a year old. I am a idiot when it comes to testing things electrically so ya all have to speak like I am a dummy. Is it possible the ballist is bad ?? Even if not very old ? I have a new one.. I just need to install it... but if that doesn work... where do I go ? ?

74 Plymouth Duster.
360
Mopar dizzy
Mopar stock electronic brain box.
Mopar stock regulator
MSD coil
Stock style ballist.

Keep in mind it ran good before on all this (except the coil) and now problems...... any ideas ???

Thanks in advance !

-RPM
 
i would slip that new ballast in there just to rule it out since it only takes a minute. then go from there
 
Might sound like a silly question, but how is your coil mounted -- vertically, or horizontally on the intake?

We had a problem with the '83 D150 440 shop truck doing the same thing after installing an MSD setup. After a few calls to the tech department, one finally suggested moving the coil to an upright position rather than laying on its side. Apparently the cooling oil inside doesn't "go all the way to the top" and they can get hot and quit working. Bertha The Shop Truck has been running just fine ever since, and the motor change was a couple three years ago now.

Just an idea! Good luck Scott.
 
Have you hooked up a vacuum gauge to see if you have an issues wit the engine? Is it firing on all cylinders? Seems the demand from Drive will kill it so the engine power might be down. Bad plug wire or misfire? Vacuum leak?
 
CudaChick1968 said:
how is your coil mounted -- vertically, or horizontally on the intake?

We had a problem with the '83 D150 440 shop truck doing the same thing after installing an MSD setup............... suggested moving the coil to an upright position rather than laying on its side. Apparently the cooling oil inside doesn't "go all the way to the top" and they can get hot and quit working.
Click to expand...

Cudachick has a point. 30 years ago, nobody worried about this, and millions of Ferds came with horiz mounted coils. If the coil is horizontal, at least make sure the terminals are DOWN and not UP.


If you are measuring coil voltage with key "in run" and engine OFF, this low voltage may be perfectly normal

With the engine running however, depending on what coil/ ballast, etc, and the system voltage, AND RPM, coil voltage can vary anywhere from 7 to 12 (14V charging). This is because the coil voltage is a pulse and the duty cycle changes. If the duty cycle pulse was 50%, it would be half battery, IE 6 if not charging (but running) and 7 if running at 14V

What are you using exactly for coils/ ballast/ box? Are they everyday Chineseo parts store stuff, or MSD blaster/ etc, or what?

Also check our running charging voltage

Basically, in simple terms, you need the coil and ballast matched

DO YOU (I hope not!!) routinely leave the key "on" with engine "off?"
 
No I dont leave the ignition key in the on position all the time.

All the ignition system components are listed in my original post.

The 4 volts at the coil is while the car is at idle. Which as I am told should be at least 8-9 volts. The voltage will also drop to 3 or less at times.

The engine does have a very slight misfire every now and then.
Plugs and wires seem to be working properly.

Vacuum could be a issue I suppose, but that wouldnt explain the 4 volts at the coil... unless... i have more then one problem which wouldnt suprise me.

I have just recieved and new vac guage set for my b-day so I will be checking that.

The coil is indeed horizontal, but has been for a long time. Keep in mind that I still have 4 volts or less using the MSD blaster or the stock Chrsyler one so one should match with the ballast.

I will change the ballast out, but I dont have a lot of hope thats my issue.

The car fires up, runs good, revs up solid..... just kills out when stabbed in gear..... yes.. we checked for torque convertor issues... everything there seems ok as well....

So ??? Vacuum or electrical I assume.

thanks people....
 
i may have missed it, but are you absolutely sure its not dumping fuel? IE stuck float ? that still wouldnt explain the low voltage..just a thought
 
Fuel is good. Carb was even rebuilt two different times. Not running out or over loading. Vehicle fires right back up after it dies as long as its in Park/Neutral.

-RPM
 
How old is the fuel pump. It do almost sound like fuel or vacuum. Spray carb cleaner all around motor, if...or when stumbles theres the leak.
 
Hey Scott ,get someone you trust to put it in gear while you test the voltage , also may be a bad pickup in the distributor. Dane
 
I would monitor the voltage from coil+ to BATT- while driving. When it dies, see if that voltage difference goes to 0 V. If so, suspect the ign switch, bulkhead connector, and ballast. Also, check that your MSD box has a good ground. A dedicated wire beats a rusty screw every day. A $5 in-line spark tester is invaluable too.
 
update... while I havent had much time to check things on the car I did do a couple things that I have read about. One thing I was informed to do was to replace the ballast. While I was pretty sure that was not the issue its cheap assurance to replace it. I did so and still have same concern. I ran my tester from the ignition side of the ballast to the battery and if I am correct it should read more then .3 mine reads at 1.3 (again I hate hate hate electrical) So I am thinking there is a bad connection or short or possible ignition switch issues. Still only have like 3volts across the coil... still instantly dies when put in gear.

To give more info to some people who have responded..... I dont have a complet MSD box. Its all Mopar stock ignition except the coil which is a new MSD Blaster (which I thought might be a problem) but the car ran for years with a Accel super stock in place...and the problem started with the Accel anyways. I have also put a stock coil back on just for giggles and it still has same issue.

I have cleaned and added dielectric grease to all the bulk head connectors and have checked all other connections to wirining that I can locate and cleaned them as well. Grounds are all good. Carburation is all good. I think I am losing voltage maybe through the new (to the car) cluster which all that runs through if I read things right. Or... the ignition switch which I have not tested properly yet.

Just crazy how it all runs good then one day... pooof..... problem.

Who knows ?? Maybe I am chasing more then one Gremlin... electrical and vacuum... or ??

Just need more time in the day to work on it !
 
RPM said:
I will change the ballast out, but I dont have a lot of hope thats my issue.
Click to expand...

The ballast does regulate voltage to the coil in the run position, and yes you should have 7-9 volts at the coil when running.

The MSD coil does require a lower OHM ballast.

Have you checked the wire from the ballast to the coil? Could be broken somewhere, just a thought. Or the wire feeding the ballast?
 
This might sound stupid, but pull the headlight switch. Check the connections and make sure the switch itself is intact. I had a similar problem and found that one connection on the switch was cracked. Had an on off effect like a light switch. Changed the switch, problem solved. Not sure if that's your problem, but it's worth a shot.
 
The headlight switch has nothing to do with ignition

The voltage drop you measured is way too much. One thing you can try is run a good heavy clip lead direct from "battery" (such as starter relay stud) to coil + and see if it fires. Then transfer the clip from the coil + to the "key" side of the ballast. You can easily find that, if the wiring is taped and hidden, by turning the key on, and measuring both sides of the ballast to ground. The side with the highest reading is the one you want. Clip your lead from there to the battery and see if she runs. If so, you have an ignition harness problem, IE bulkhead, ignition switch/ connector, or even the so called "in harness" welded splice

Another thing(s) to do if you have not is to remove, inspect and replace the bulkhead connectors, and remove all the ignition system connectors, ballast, ECU, and dist. and "work" them in out to scrub the terminals clean, and to "feel" for tightness.

And check the dist reluctor gap, although I know you said you tried another.
 
67Dart273 said:
The headlight switch has nothing to do with ignition

The voltage drop you measured is way too much. One thing you can try is run a good heavy clip lead direct from "battery" (such as starter relay stud) to coil + and see if it fires. Then transfer the clip from the coil + to the "key" side of the ballast. You can easily find that, if the wiring is taped and hidden, by turning the key on, and measuring both sides of the ballast to ground. The side with the highest reading is the one you want. Clip your lead from there to the battery and see if she runs. If so, you have an ignition harness problem, IE bulkhead, ignition switch/ connector, or even the so called "in harness" welded splice

Another thing(s) to do if you have not is to remove, inspect and replace the bulkhead connectors, and remove all the ignition system connectors, ballast, ECU, and dist. and "work" them in out to scrub the terminals clean, and to "feel" for tightness.

And check the dist reluctor gap, although I know you said you tried another.
Click to expand...

It doesn't? Guess I was wrong then.
 
I had a problem similar to this with my dart when I first got it, at idle voltage would drop way down but then pick up at higher RPM's. If you have any #8 or #10 wire hanging around that's long enough run a piece from the alternator directly to the battery positive. Might help with your problem, fixed mine as the voltage was dropping as it ran through the bulk head connecter, to the ammeter and back out to the battery.
 
Column shift linkage grounding out the starter harness ?
 
Check the terminals on your amp gauge, bet you find one is a little darker. They will bleed off voltage and shut the car off. My 78 Power wagon would do the same thing, driving along it would just shut off, pull over put it in park, and it would fire back up.
 
Next time you measure 4 V at coil+ (to gnd) when running, measure the key side of the ballast to ground. It should be the same as BATT+ within ~0.5 V. If much lower, keep going upstream until you find the culprit. Start at the key switch IGN terminal. Make sure your ground in the cabin is the same as your engine ground (less than 0.5 V drop). Of course, across the battery should measure 12.6 V or higher when running.

If the voltage is OK on the key side of the ballast, then you have too much drop thru the ballast or wiring to coil+. There are many different ballasts and coils and they don't all play well together. Too confusing for me. I just run HEI with no ballast in all my cars but my Newport (planned). For your 360, you can get an HEI distributor and E-core coil for ~$70 on ebay and kiss ballasts goodby. Look up "ready to run" and "distributor". I got mine from stevewhite.
 
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