MP Ignition not firing

[TBass]

So I done an engine swap on my Charger over the weekend. I went ahead and converted to MP electronic ignition. I went to check the fire and it appears to be firing from the coil to the distributor, but not from the distributor to the plugs. I am guessing the pickup inside May be bad, or possibly not gapped right? I noticed it says to set the gap at .008", as I did, but the gap appears to be uneven. At the top of the contact it is quite a bit closer than near the bottom. Did I become the lucky guy who received a defective one? Has anyone had any problems like this getting theirs going? It is a brand new MP kit from Summit.

 

[69Bee]

If it is firing anywhere, the pickup is not your problem. Look at the distributor cap, and make sure the carbon button is in good condition. I had one that fell out, so no fire. Also look at the rotor for issues. lastly, if the coil fires, but no fire thru the cap, get another cap to rule out a bad carbon button. Sometimes they burn out, and will no longer conduct.

 

[440+6]

My pickup to reluctor gap is a bit crooked too and it works fine, I agree with Bee if it's firing from the coil the problem is between the cap and rotor.

 

[TBass]

Got it. It apparently I had a loose connection. Soldered all my ends and it fired right up.

 

[TBass]

So now that everything is firing and I got my exhaust hooked up, I hear a distinct high pitched noise that I swear is electronic. The pitch gets higher as the RPMs increase and you can hear out under the hood. Do there MP ignitions commonly do things like this? I can't nail it down to the module or the dustributor, but it's there for sure!

 

[TBass]

Yup! That's it! I need suggestions yet again. My MP distributor has an annoying high pitched squeal coming from it. The pitch increases with RPMs too. It is a brand new ignition system too. I have yet to hook up the vacuum advance because I wanted to get the mechanical stuff squared away first. Also. It pops through the exhaust around 1500-1600 RPMs. I have about convinced myself it's all distributor.

Any help will be greatly appreciated.

 

[TBass]

Well, I made it back from my trip across the pond again. I dug the Charger out of storage and began tinkering with it. Immediately it began giving me ignition headaches again. As mentioned above, I worked through the gremlins in the earlier part of this thread. I now have a new issue. My ignition will not fire until I turn the switch to "off". I have experienced this issue on old Ford Duraspark systems before and never figured out the direct cause. Eventually I switched to MSD and was free from that headache. I don't wanna do that in this case.

I have read that it is the switch, the bulkhead, the coil, the orange box, the ballast, connections, etc. I am guessing this issue is in the new equipment. Pickup coil, module, whatever. Does anyone have any insight? ECM is grounded, switch, bulkhead, coil are the same as I was running trouble free with my points ignition. They worked great. I am prepared to start replacing parts, but asking for suggestions on where to begin.

Last year it was dong the whole thing where it seemed as if it was vapor locked. I can't even get it to run in order to work through that issue now. I have swapped the ballast from my friends '70 and it made no difference.

Any help with this would be greatly appreciated.

 

[440roadrunner]

First, understand how Mopars work, "different" than Ford

Mopar is the only manufacturer which put the coil ballast bypass circuit "for start" in the ignition switch. Ford /GM does this via the solenoid, the "extra terminal."

You have TWO ignition sources coming from the ignition switch, through the bulkhead connector, to the igniton

IGN1, traditionally dark blue, is "run." This supplies the ballast, the VR, alternator field (70/ later) and a few other smog duu dads on some years. THIS SOURCE GOES DEAD during cranking

IGN2, traditionally brown, comes off a separate igntition switch contact, goes through the bulkhead, to the coil + side of the ballast. THIS IS THE ONLY source of ignition during "crank."

So (some years) if the dual ballast is bad, or if the ignition switch is bad, the car will not fire in crank, but if you get the engine turning, and snap the switch back to "run" sometimes it will "pick up" and run.

The opposite can also be true. If the run circuit fails, the car will start, but will only run if you "play" with the key halfway back from "start."

Pull the ballast connections loose and unplug the ECU.. This isolates the circuit. Find the brown wire coming out of the bulkhead to the ballast and hook a light / meter to that. Verify "if" it has voltage during cranking.

Find the blue "ignition run". This goes to the ballast, and VR. See if you have that with key in "run."

Check the ballast for continuity.

Otherwise, do the 'wiggle test' on all ignition connectors, the pickup, the ballast, and the ECU.

MAKE CERTAIN the ECU and VR are grounded. The ECU MUST be grounded to operate.

 

[coloradodave]

Great help 440roadrunner, but needs a little proof reading:

Please change the first IGN1 to IGN2.

Otherwise, great explanation.

 

[TBass]

I did all of this today. No change so far. I am almost positive it is something going on witht the "run" wire. I even hotwired it to try and see if I could force it to fire and got nothing. As I was cranking it, I quickly unhooked the Hotwire and hooked it back up and it tried to start. But could not get anywhere beyond that.
At this point I would drop my points distributor back in if I still had it.

 

[Gpuller]

Got another ECU to try?

 

[TBass]

Not yet. I am thinking that is the next thing to do. I might have to swallow my pride and round up some of the brand X guys around here to help shove this beast up the driveway until a new one arrives.

I am looking up different wiring diagrams in the meantime. I'm telling y'all, what I have wired here us not normal and I have found multiple methods. None that match what I currently have. However, what I have is exactly what my instructions said to do. And it worked! Now it don't. So, we all know this story in some way or another.

 

[440roadrunner]

Great help 440roadrunner, but needs a little proof reading:

Please change the first IGN1 to IGN2.

Otherwise, great explanation.

Thanks and done

- - - Updated - - -

Not yet. I am thinking that is the next thing to do. I might have to swallow my pride and round up some of the brand X guys around here to help shove this beast up the driveway until a new one arrives.

I am looking up different wiring diagrams in the meantime. I'm telling y'all, what I have wired here us not normal and I have found multiple methods. None that match what I currently have. However, what I have is exactly what my instructions said to do. And it worked! Now it don't. So, we all know this story in some way or another.

OK, here is the deal. SOME diagrams you find online are "mirror" at the ECU harness connector that is looking INTO the plug instead of "down at' the ECU itself.

Also realise that the ORIGINAL points resistor wiring is UNCHANGED. That's right, there is no change to the old ballast wiring.

Here is a good diagram, I assume you have a new kit which is a so called "4 wire" ECU The top right going off the page is the original blue "IGN1" or "run" wire. What is not shown is IGN2 (brown) to the bottom of the resistor. That will be there in your car. NOTE this diagram is looking DOWN at the rear of the harness plug as it is plugged into the ECU

- - - Updated - - -

Some checkpoints............

The ECU MUST be grounded. (So must the VR). Scrape around the mounting flange on the rear, and around the bolt holes. Mount using star lock washers

SOME CHECKS

With the key in "run" check voltage at coil + and coil -

Coil PLUS will be somewhere between 4-8 volts because it is going through the ballast resistor. It it is "really high" like "same as battery" then the system is NOT drawing current through the coil. Either ECU is not grounded, coil is bad, or miswired, or ECU is bad

If the above is OK take a grounded probe (even a 12V test lamp) and hold into the top of the coil tower. Take the ECU end of the distributor harness connector and touch the bare terminal repeatedly to ground. Each time you do so, a "snap" spark should occur.

If that happens plug in the distributor. "Work" the distributor connector in/ out several times to scrub the terminals clean. Get yourself a BRASS .008" (inches) feeler gauge and check the reluctor gap. Check in under there for damage, strike damage, rust, or foreign debri. Crank the engine and see if you have spark

If not, jumper 12V direct to the coil POS terminal and try again.

 

[TBass]

Alright.......a local Mopar buddy brought a box full of things to try tonight. Just for an extra set of eyes and another brain to fry over this. We went through the wiring and he verified that I was right in how it is wired. We switch ECUs to one he had. No change. We switched to a 6AL just for the heck of it and it fired up and immediately died then went back to the original issue. Switched back to my original ECU and it fired up and no further change. After scratching our heads about it, he hooked his test light to the + post on the battery and touched the posts on the ballast with the key "off" and it showed them both as being grounded. The ECU is also getting a solid ground. So that is not a concern. At this point, I am thinking that after sunrise tomorrow I am going to check the reluctor. If that is still at .008" I am pretty certain I am going to grab a coil from "the Zone" and see where it stands. That whole thing with the ballast posts being grounded tells me we have revealed an issue and I just gotta isolate it.

- - - Updated - - -

Thanks for your help. This diagram is telling me where a wiring issue exists. The "new wire" (light blue w/yellow tracer) is currently in the wrong location. I will move it to the other side of the ballast.

 

[mopar 3 B]

Check the unit grounds with an ohm meter to battery ground. Do not assume just because everything was clean and tight the ground is good and yes use star washers and bolts if needed for fasteners. If you do not have a good ground it may run but the ECU is going to overheat and melt gound and you do not want that Mopar setting stranded.

 

[TBass]

Problem seems to be solved by moving that wire. It fired right up and rumbled around better than it has ever ran. Thanks for all y'all's input!

 

[TBass]

Spoke too soon. After idling for five minutes it shut off like it suddenly lost fire and immediately went back to the same symptoms. I have a new coil on the way to eliminate that possibility.

 

[TBass]

Well, it wasn't the coil or the ECU. I have replaced both of those and the ballast. It runs solid and then after something gets up to temperature it shuts off as if I turned the key off. Try to start it back and it goes back to only firing when the switch goes back to the "off" position. I am thinking pickup coil or ignition switch. I am still asking for suggestions from anyone that can help.

 

[Shorthorse]

Your issue seems to have a common component. It runs until the heat builds up and quits. You said it wouldn't start after that. I'm guessing it will start after it's cooled down. Since it appears that you can duplicate the symptom easily, try this.
We used to use freeze spray on electrical components that would fail when they got hot. It was non conductive. Fire it up, let it fail and immediately spray a suspected component (coil, ECU, ballast resistor), one component per test. Then quickly try to start the car. Who knows?

 

[440roadrunner]

You changed coil? Ballast? Heating up and quitting is classic coil failure.


Make CERTAIN distributor reluctor gap is OK, .008" (inches) with a brass feeler, and wiggle and "work" the 'ell out of the distributor harness connector to 'scrub' it clean, and "feel" for tight fit.

If you can, measure "ignition run" voltage to the ballast IMMEDIATELY after it quits, just let it die, don't move the key, and check for power there.