Strange starting issue

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sledger46

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Hello all,

Some background information: the car is a 67 Dart with a 360 LA conversion from /6. The car has a Summit Racing electronic ignition conversion kit. The problem I having is this: the car cranks but has no fire until you release the key to the run position and then sometimes it will catch and run. I am thinking I have a bad ignition switch.
What do you think?
 
No voltage for ignition during cranking , check starter solenoid or alternator . Ignition is usually fed through these during crankingof engine .
 
Here's how Mopar starting systems work:

You have three important wires and separate switch contacts in the ignition switch

(Actually 4, including the accessory switch circuit)

You have the traditional "dark blue" hot in run, feeds ignition system, charging system (regulator) and power to instruments and oil light NOT FUSED

You have the traditional yellow which triggers the start relay if the trans is in park/ neutral

You have the traditional BROWN from the key which BYPASSES the coil resistor in start.

So on one side of the coil resistor you have a wire going to the coil AND the BROWN

On the "key" side of the resistor, you have the 'dark blue' coming from the key, and tapped off to feed the regulator

You need to make some checks with a meter

First, if this uses a Mopar style magnetic distributor, make sure the reluctor is gapped correctly

Second, Take your meter and hook to the "key" side of the ballast. Turn the key on, engine off. You are looking for voltage with LESS than 1/2 volt difference from the battery. A better, more direct way to measure this is to turn the key to "run" and place one probe on the "dark blue" at the ballast, the other probe directly onto your battery positive post. If you read more than 1/2 volt (and that is generous) you have a problem, either with wiring, or mroe likely the connections at the resistor, the bulkhead connector, the connector on the ignition switch, or the switch itself

Next, check your "cranking" power. Clip one lead of your meter to the coil POS terminal, the other to battery pos. post. Crank the engine USING THE KEY. You should once again read NO MORE than 1/2 volt DROP. To double check, measure from coil POS to ground while cranking. You should get very close to "same as battery" IE 10.5 volts or higher.

IF this is low, once again, it indicates a drop through the bulkhead connector, the ignition switch connector, or the switch itself.

Get back into the switch and check there if any question as to where you are "losing juice."



NOTE with your specific problem, concentrate on the "brown" on the coil side of the resistor. You are PROBABLY suffering a poor connection at the bulkhead connector
 
DFootCuda said:
No voltage for ignition during cranking , check starter solenoid or alternator . Ignition is usually fed through these during crankingof engine .
Click to expand...

Sorry, way off the trak, here.
 
I started checking voltages and found the coil was getting 10.50 - 11.0 volts during crank and 6.5 volts while running. Maybe I should check to see if the ignition box is getting any voltage while cranking. The car cranks fine but still will not start until the key is returned to the run position. This is almost like the exact opposite of a bad ballast resistor.
Any more ideas?
Thanks
 
jump the ballast and see if it quits doing it, after that...I would look at the ign switch and its connections all the way through the bulkhead.

I had this happen before about 7yrs ago intermitantly , the ballast failed shortly after.
 
sledger46 said:
I started checking voltages and found the coil was getting 10.50 - 11.0 volts during crank and 6.5 volts while running. Maybe I should check to see if the ignition box is getting any voltage while cranking. The car cranks fine but still will not start until the key is returned to the run position. This is almost like the exact opposite of a bad ballast resistor.
Any more ideas?
Thanks
Click to expand...

Maybe an intermittent

I'm not familiar with what you mean by a "summit" system is this the same as Mopar ECU system, or what?

If so, check the gap in the dist. Unplug the dist pickup and hook your meter to the dist. connector. With the meter on low AC volts, crank the engine, and look for 1V AC OUT of the dist.

Might be wiring/ connector at the box??

"Push/pull" the box connector a few times to scrub it clean.
 
http://www.summitracing.com/parts/SUM-850003/

This is a copy of the MP electronic ignition conversion. Comes with a new distributor, control module, and wiring harness. I picked up power for the control module from the run side of the ballast resistor. I checked the air gap in the distributor and it is set at .008 as per the instructions. I haven't tested the voltage to the contol module (ECU) with the engine cranking yet.

Another symptom is the tach I have registers fine at an idle but begins to fluctuate as you slowly rev it up to 2,000 - 2,500. It will fluctuate 300-500 RPM. What I find strange is the tach fluctuates up instead of down. I replaced the spark plug wires, replaced the ground to the body at the battery, and replaced the ground from the back of the motor to the firewall, but this problem persists. I also changed the ground for the tach itself with no change.
Thanks,
 
I checked the voltage to the ECU and found 11.50 V in the run position and 1.3 V while cranking. I also tested the distributor and found 275 ohms across the two wires and only got .2 -.3 VAC while cranking.

Thoughts?
 
The ecu should get 12 volts during both crank and run. You have it tied to the wrong wire. the ecu should be 12 volts from the same blue wire feeding the volage regulator.
 
RedFish said:
The ecu should get 12 volts during both crank and run. You have it tied to the wrong wire. the ecu should be 12 volts from the same blue wire feeding the volage regulator.
Click to expand...

Yup. Somehow you have the coil power and ECU power separated, or a break in the harness. I would have thought that the kit would have been pretty straightforward.
 
67Dart273 said:
Yup. Somehow you have the coil power and ECU power separated, or a break in the harness. I would have thought that the kit would have been pretty straightforward.
Click to expand...
They are different sources. The 67 ballast resistor has a hot in start and a hot in run. The power to the ecu , along with the voltage regulator is hot in both start and run.
 
RedFish said:
They are different sources. The 67 ballast resistor has a hot in start and a hot in run. The power to the ecu , along with the voltage regulator is hot in both start and run.
Click to expand...

You lost me there, bud

There are only two contacts on the ign switch, "run" (ign1, dark blue) and "bypass" (ign2, brown)

The run circuit (dark blue) goes cold during crank, the brown should feed "hot" 12V to the coil, and BACK through the ballast to the ECU

If the dark blue "run" feed to the ballast is bad/ disconnected, you won't get anything to the ECU

During crank, the brown bypass/ ign2 will feed power directly to the coil side of the ballast, AS WELL AS "back through" the ballast to the junction point of the dark blue, and feed power to the ECU

So a light dawns--It suddenly occurs that I'm not sure the "run" circuit goes cold on newer (72-3) factory electronic ignition cars

(On mine, I'm now running an HEI module with no ballast, so no longer applies.)
 
I tried connecting the power for the ECU directly to the battery and the car started right up. With the ECU connected this way the tach responded normally without the jumping around as I slowly rev'ed it up pass 2,ooo RPM. The switched power source I could find close was the blue wire running into the voltage regulator. One concern though is that during cranking it was only registering about 8 volts. I was expecting to see at least 10.5 volts. Any other good places to power the ECU?
 
You do need to cure the voltage drop. The gauge of the wire in a 67 harness really isn't sufficient for a bunch of add-ons under the hood. Add that to poor connections and nothing will work as it should.
 
I already added a Painless secondary fuse block with it's own feed to the battery to run additional electronics. When I tried to connect the ECU to it I found that during cranking the switched source in the original fuse block used to enegized the relay for the secondary fuse block loses power. I think the new plan would be to tie the switched circuit signal wire to the voltage regulator wire since it is very low draw. Then I will tie the ECU to the secondary fuse block.

The Painless secondary fuse block has it's own power feed to the battery protected by a circuit breaker right by the battery. The fuse block has 1 constant 12V circuit and 2 switched 12V circuits. The seconday fuse block uses a signal wire to an existing switched circuit to power the relay that switches on the 2, 12V circuits. I used the secondary fuse block to power my stereo and my gauges inside the car.
 
Doesnt it all go through the amp gauge?

check continuity on'em but....maybe pull the feed from there and go through the painless box 1st?

I have a '67 myself...and after all the dim headlights and shorted charging system wiring...I finally just had the whole car rewired 'heavier gauge' and had a headlight amplifier installed. Now I can run my 800 watt stereo, msd, heater, and whatever else I want with no voltage dip or dim gauges....cost $575 but came with a lifetime warranty, which is almost unheard of in electrical work.
 
Who did the wiring or was it a kit?

The Painless secondary fuse block does not run through the dash amp guage. If a DUI HEI would fit under the wiper motor I would put that on and eliminate the ECU and Ballast resistor. I will eventually put on a 1 wire alternator and eliminate the external regulator. As it stands right now the only guage in the dash that works is the ammeter. I had the speedometer working for about 10 miles before it quit again.

One of my most vivid memories was driving my 73, 340 Cuda through the country on a star filled night with that special lady in the passenger seat and hitting a cross road and as the Cuda bounced over the intersection everything went black and the motor went silent. 60 MPH on a crowned road in pitch black, well except for the stars. I did manage to get the car pulled over safely. Luckly I knew to push the all the connectors back into the bulk head connector and get it started again. The joys of Chrysler/Plymouth electrical systems ;-)
 
When things dont work in the electrical system....it's a good idea to find out why/fix them, becuase they can later turn out to be the short that burns the car to ground.

Aldo's auto electric vista ca is who did my valiant, great work...and he completely bypassed that bulk head altogether.
 
OK, on your secondary block losing power. You need a bypass SEPARATE from the start relay There are about three ways to do this

Get a "big" diode from Rad Shack and wire it from the start relay signal to the power intput of your auxiliary box to the relay coil(s)

Or fire a separate relay off the start relay signal and use it's contacts to power the box during start

Or get a late model start relay (not sure what all they fit, some Jeeps) which has FIVE terminals like this:

http://www.fourwheelerhb.com/ShowItem/109944 RELAY.aspx

109944.jpg


These new 5 terminal relays have an extra set of contacts that can be used for this purpose.

But let's make one more check-----hook everything up "normal" and with the key in "run" and the engine OFF what voltage do you have at both sides of the ballast?

And can you check the voltage going to the box without disconnecting the ECU connector? (One way is to stick a pin in the wire before it goes into the box)
 
In the run position I am seeing 12V on one side and 6V on the other side of the ballast. The ECU is currently connected to the blue feed wire for the voltage regulator. Without the ECU connected I was seeing 12V in the run position and 8V while cranking. I will have to stick a pin in the wire and get a reading with the ECU hooked up when I get home from work.

In order for the Painless secondary fuse block to have power on the switched circuits during cranking I need a switched circuit on the existing fuse block that remains powered during cranking. The switched circuit on the original fuse box is used to energize the relay that applies power to the switched circuits in the Painless secondary fuse block.
Thanks,
 
There is no such switched circuit, that's why I made the suggestions. The switch on those cars has:

Battery in to the switch

Accessory out, off in crank

Ign1 out, (run, dark blue) off in crank

ign2 out (resistor bypass, brown) hot only in crank

start relay signal (yellow) hot only in crank

You cannot just hook the brown or the yellow up directly, you must either use a relay or diode as I suggested, because when you release the key to run, the dark blue run voltage will feed back. This is why the brown bypass circuit is a completely separate contact --there's nothing else hooked to it, so the run voltage cannot feed back to anything.
 
Voltage to the ECU:

Key on/Engine off: 10.9V
Cranking: 7.9V
Engine Running: 11.5V

The ECU is currently tied to the blue wire running to the voltage regulator.
 
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