no power to spark plugs

[moparjohnny]

69 383 eng i just added new msd blaster coil,it has a old orange ecu box,so where do i start?how to test with multimeter the ecu box?electronic dizzy has some brittle old wires,i will replace all this old stuff,but for now any ideas?has new voltage regulator and new starter relay on it.plugs do not look fouled out or anything.thanks

 

[Jcharger]

I would check several things.

1) make sure there is voltage at the ballast resistor (and coil) in the key on position and in the start position. I am guessing they will be blue and brown wires to the ballast resistor. Also check continuity to make sure you are getting voltage to the coil
2)Check the coil resistance by reading from positive to negative and positive to the central post. One will be in the Kilo ohm range (I think 4.7) and the other will be in the ohm range (I think 0.7). This will tell you if the windings are continuous.
3) There is also a test to see if the coil will fire by tapping it with a ground. A lot of these are described on the web (e.g., http://www.aa1car.com/library/ignition_coils.htm). I think the coil is fired by grounding rather than building up a voltage.
4) The coil is fired by the ECU which is signaled by the distributor. I will assume the feed from the distributor is a hall effect sensor. This is basically another coil that can have the resistance measured. It should be continuous and have a resistance. I do not know what this is. The sensor also should output an a/c voltage when the distributor is spun (I think order a volt or less and this can be tested.) I do not know where the test is.
5) I do not know how to test the ECU, but know there are tests for that.


This is the extent of what I know. Others will chime in with better information. Also I often check on youtube or other searches to see some of the tests.

 

[PurpleBeeper]

One old trick I've used to check the wiring, coil, ECU & ballast resistor (if equipped) is as follows:
1. Unplug center wire from distributor cap, insert a Phillips screwdriver into the end of the wire & place that wire/screwdriver combo about 1/8" from a good ground.

2. Unplug the double-wire plug going to the distributor. One terminal (male) will be exposed and the other one (female) will be enclosed in the terminal end. You will be working with the plug that goes to the wiring harness.

3. Turn key to "on"

4. Temporarily touch the exposed, male end of the distributor plug (wiring harness side, not distributor side) to a ground. On a big block, the bolts holding the intake belly pan front hold-down is a convenient ground locations.

5. When you touch the distributor plug to ground, a spark should jump from the screwdriver (attached to center plug wire coming from coil) to the ground that it's near. Basically, your screwdriver is a "test spark plug".

6. If you have spark, then the coil, ecu, and wiring are good and the problem is in the cap/rotor/plug wires (or distributor pickup). If you have no spark, then start back tracking where you do/don't have power like Jcharger suggests.

If it worked before the blaster coil, try the old coil. The main problems Mopars have are #1 ballast resistor & #2 the ECU itself.

 

[moparjohnny]

One old trick I've used to check the wiring, coil, ECU & ballast resistor (if equipped) is as follows:
1. Unplug center wire from distributor cap, insert a Phillips screwdriver into the end of the wire & place that wire/screwdriver combo about 1/8" from a good ground.

2. Unplug the double-wire plug going to the distributor. One terminal (male) will be exposed and the other one (female) will be enclosed in the terminal end. You will be working with the plug that goes to the wiring harness.

3. Turn key to "on"

4. Temporarily touch the exposed, male end of the distributor plug (wiring harness side, not distributor side) to a ground. On a big block, the bolts holding the intake belly pan front hold-down is a convenient ground locations.

5. When you touch the distributor plug to ground, a spark should jump from the screwdriver (attached to center plug wire coming from coil) to the ground that it's near. Basically, your screwdriver is a "test spark plug".

6. If you have spark, then the coil, ecu, and wiring are good and the problem is in the cap/rotor/plug wires (or distributor pickup). If you have no spark, then start back tracking where you do/don't have power like Jcharger suggests.

If it worked before the blaster coil, try the old coil. The main problems Mopars have are #1 ballast resistor & #2 the ECU itself.

 

[moparjohnny]

i check coil today primary and secondary is good,mounted to engine and used a coil tester that you connect a prong to inside coil and a spark plug on the other end and cranked eng and the light did not light up to indicate power to coil,what is next the ecu orange box,no power to coil and of course no power to plugs,how do you check ecu box? how do you check the voltage regulator? i do not have a ballast resistor on this mopar orange box system.thanks

 

[Jcharger]

I have not worked with an orange box, but it seems to me that you need to determine whether you get power from the key to the coil and orange box in both the run and start positions. I would look to see if you measure a voltage from the positive side of the coil to ground when you are in the run position and also when you are in the start position. This would be the blue and brown wire that would normally go to the ballast resistor (they must be tied together if you do not have a ballast resistor). I had thought they were tied together only in cases where the ecu supplied all the voltage to the coil like the MSD (but as I mentioned I have not worked with an orange box before). I got my information by inspecting a diagram like that online at: http://www.forwardlook.net/forums/forums/thread-view.asp?tid=27487

Someone who has worked on these will be able to confirm.

 

[Darthomas]

Coil MUST have ground to block, the
shorter the better if a wire, and it really wants to be bolted to the block.
The coil paint must get nicked through for current to complete in the secondary circuit through each plug.
Otherwise spark must jump at plug, dist cap AND through a layer of paint which is insulation, more or less.

 

[moparjohnny]

Coil MUST have ground to block, the
shorter the better if a wire, and it really wants to be bolted to the block.
The coil paint must get nicked through for current to complete in the secondary circuit through each plug.
Otherwise spark must jump at plug, dist cap AND through a layer of paint which is insulation, more or less.

car was cranking fine until i changed distributor and i got tdc back and it has cranked a few times and died since then.and we found no power to plugs,something is getting intermitten power at times and then power stops after a few minutes of running time or until something gets hot and shuts down,

 

[Darthomas]

Also needed is a VERY good ground strap from block to body in 2 places.
One near the battery, another near the firewall and or fender where the ignition control box is.

 

[moparjohnny]

Also needed is a VERY good ground strap from block to body in 2 places.
One near the battery, another near the firewall and or fender where the ignition control box is.

problem resolved,i just pulled out orange box and distributor and put my mallory dual point distributor in and it fired up ran good,no problems,i will keep mallory on it and not use electronics,points are more simpler,in the 60 era that is all we had and they did just find from the factory with points and we had enough speed and power,if i was drag racing i would do electronics,but i am happy with the way car runs and it is fast enough for me,points if put on correctly can last a while,and my driving which is occasional and some car shows, not many miles will be put on car anyway,so i am good. thanks to everyone who helped.

 

[miller]

Ahhh...good show. Heck, don't hurt a thing to have to do a little tune-up, once a year, and go on with the program!

All that 'electronic' stuff is good for is breaking, and throw it out.

 

[Darthomas]

I'm abouy to throw new points into a 225 after ? miles/years. Getting ragged just off idle. Can't wait to see how dished out they are. Have some good Standard Blue Streak points. But you can't get the "real" Blue Streak points with the cam grease felt holder anymore. Still the best, even though it's the red box instead of the blue box....

 

[Darthomas]

They were pretty ugly.
Always keep old points for....good measure. Some day they may save you a tow job.

 

[coloradodave]

Electronic ignition won't make a car faster compared to a correctly adjusted point type ignition. The advantage is that the "tune-up" doesn't degrade over time. That's good for those of us that are lazy... Personally, putting my own 'touch' on the point settings, especially dual point distributors, is something I miss from my younger years. Glad you're up and running Johnny.

 

[miller]

But you can't get the "real" Blue Streak points with the cam grease felt holder anymore.

Crummy deal getting parts these days. But, maybe I'll invest in a cheap felt hat! I can make those wipers all day long, and have enough special oil for them to last many lifetimes.

 

[moparjohnny]

Electronic ignition won't make a car faster compared to a correctly adjusted point type ignition. The advantage is that the "tune-up" doesn't degrade over time. That's good for those of us that are lazy... Personally, putting my own 'touch' on the point settings, especially dual point distributors, is something I miss from my younger years. Glad you're up and running Johnny.

that is what i like also personal touch and some good old days with these cars.i think electronics are good for those who like them and of course some change is good.

 

[Darthomas]

I don't appreciate any change that promotes or supports ignorance.

I've never had to make a bowstring and roll a stick in tinder and a small branch to make a fire, but I know HOW to do it.