Mopar Muscle Association UK

Hi, I haven't been able to get my 400ci '73 Charger running for a month.
The carb and timing were set up on a rolling dyno, so i don't believe they are an issue, (and the fuel is getting through to the Edelbrock 750cfm).

The voltage regulator fried and I think it may have destroyed some ignition parts. I have changed the Voltage Reg, Control Unit, Coil, Dual Ballast, Pickup Coil and Rotor Arm and still cannot get a regular spark. The Bulk Head connector has been stripped, cleaned and greased. I seem to get one spark as I turn the key, then another as the key returns to the off position, (nothing in between).

My regular auto electrician spent several hours checking for voltage here, there and everywhere, by-passing different circuits as he went, all to no avail.

I am open to suggestions, but bear in mind, we've tried and tried all of the obvious.

What I'm really looking for is someone in the Southend-on-Sea, Essex area who really knows their way around a Mopar Electronic Ignition system. Can anyone recommend someone?

Thanks in advance.

That could be the ignition switch faulty,only making contact as the key is moved.

i had this same prob once mine would only try firing when coming off the start position, found a break in the rubber block that connects to the dizzy rubber block (2 wires) run a jumper wire to bypass the block, got to be worth a try i spent a few days before finding that, i guess it must have been feeding back through the one wire

Turn ignition on and use a screwdriver to the bridge the starter relay and see if the car starts. This will tell you if the ignition switch is at fault.

I had a similar problem, it turned out to be fried wiring/connector block underneath the steering column. I replaced the ignition switch and it cured it.

Thanks for the replies. The weather is keeping me away at the moment.
Is summer over already?

I have tested and replaced the distributor Pickup coil. Nothing.

I have measured voltage at the ballast resistor at 9v & 12v respectively.
I have also tried ignition in "run" position and shorted the starter. No go.
I have wired the coil direct to 12v and turned the starter. Still no go.

All the obvious, (and not so obvious), tests and replacements have been carried out by myself and the auto electrician.

What I'm really after is a Mopar Mechanic who can come around and get the car running.

Any ideas?

that smacks of the wires from the ignition switch being in the wrong place on the ignition switch

or the wrong place on the bulkhead connector

you are getting spark in the start position but not in the run position
or Vice versa
possibly because something to do with the 3 wires from the ignition switch is mixed up


4 wire connected switch

1 wire brings 12 volts

1 wire powers accessory circuit in the ON and RUN position
1 wire powers Ignition in the run position
1 wire powers ignition and starter solenoid in the start position

get any of this mixed up and you can end up switching off the coil in either the run or start position.

if it isn't this. then you have burnt one of the contacts in the igntiton switch
suggest its the 12 volts to coil in start position that isn't working. i.e you don't have any coil action when in start but you do when in run i.e too late to start the car.

if you have had the ignition switch apart you can further complicate matters because the slider contact can be put in 180* out which reverses the positions on the switch

Dave

Hang on

12 volt direct to coil and it still didn't start?


dead coil?
or bad earth of engine to body to battery?

or there is no power to your ignition module

Dave

I have an Accell & a brand new Mallory coil, both test good, (ohms & continuity)

Good earth lead Battery to Engine Block
Good engine earth to body

12v to ignition module

This is not the average electrical gremlin. It's often said it's a mix of Voodoo and magic, I think someone put a Hex on it.

The ignition switch tests fine although it has not been replaced, howevever, if it was at fault, then by-passing the ignition system would surely start the motor.

I suspect the ECU. I had a "new" one that was DOA.

Ignition module well earthed?

It's had my original Chrysler module, two brand new "standard" modules and a mystery module with "FSO or FSU" brand, (can't remember).

Module is bolted to firewall with no paint and has been earthed direct to battery.

have you had the dizzy out since you had it tuned?

is TDC on your balancer TDC


dizzy in 180* out?

lift it turn rotor 180 degrees and put it back in


neutral safety switch? or remains of that circuit causing you problems I've never had one of them so I don't know if the work on the starter circuit or the ignition circuit or both.


what you describe is like the coil is switched on with the key. doesn't spark and only makes a spark when you switch off with the key

that makes it sound like the ignition module has the coil on all the time and can't switch it off for each pulse of the pickup. which would indicate that something is wrong at coil negative.
the coil is controlled by the module by lifting alternating an 0 volt earth and a 12 volt signal to the coil negative pin thus switching it on O volt at negative and off when the earth is cut off

at the moment the only time the coil stops conducting is when you switch off the ignition


Dave

If the dizzy was 180' out, surely it would still fire, just at the wrong time. The dizzy has been out, but I'm 99% sure it went back the same as the engine had not been cranked, and I marked the position of the Rotor.

You are correct, the coil primary does not seem to get the interrupt signal as it should. If I manually short the coil to Earth, I do get a spark with the ignition on.

Neutral safety switch has been checked and is good. If it was bad, it would disable the starter solenoid and the motor would not crank.

if its a 73 does it have a wire from the charging circuit into the loom for the module?

OR

try disconnecting the tacho


something might be holding coil negative high.

i.e power from alternator
or a busted dash regulator via the tacho

do you have a points Dizzy to hand?

Dave