Two Times Can't be a Coincidence...Dart not Firing

[Dodge72]

EDIT: Oh darn it, posted it in wrong forum. If it could be moved to the Slant 6 Forum I'd appreciate it, thanks.

Two days ago I had a weird occurrence happen with my Dart. It's been running reliably for about 4 months now, driven almost every day. But two days ago I parked my fully warmed up car, shut it off, realized I had forgotten something and had to go back home. I didn't pump the gas (it was only 30 seconds) and cranked it. And cranked it. Nothing. I pumped it once, and cranked. I held my foot to the floor, and cranked. Got nothing. I also noticed my oil pump light was on. I just checked the oil, right at full line. It's been doing this for maybe a day, where it turns on but the second the engine runs it shuts off. Check rotor and cap, and my rotor's metal tab was bent way out of shape. Odd. I tried bending it back to a normal shape, but that helped nothing.

Finally had some help come along and we pulled a spark plug wire to test for spark. I cranked it and not even for a split second, she fires up on 5 cylinders. Turned it off, put the plug wire in, turned it on, and made my way home.

I didn't manage to get a new rotor, I was real crammed with class and work. Two days later, tonight. Off of work, it's raining, motor has been sitting for 5 hours. Drove and turned on like it should all day. I turn it on and it turns right on. But I was cold and tired and wanted to go home, so I let it go for only about a minute before pulling into reverse. Big mistake! Motor dies. It's happened before, so I try cranking. Crank crank crank. This time, I ended up having to get it towed home.

I don't know what the hell is wrong. The two times it happened were very different scenarios; first time was sunny, motor was warmed, and I was in park when I shut it off and tried again. Second time was raining all day, motor had time to cool, and it died when going into reverse. Oil light was on in both instances when key was on. Second time, the motor almost sounded like I shut it off when running (like a shudder of the motor) when I flicked the key 'off' sometimes. I have Mopar EI installed, and a Super Six with a Carter. My guess is that it is something electrical. Sorry for the story, but I gave all the info I could. I'll be inspecting it tomorrow.

 

[AJ/FormS]

My guess is
Each "no start" was for the same reason, but different circumstances.
1)But first;let's talk about the oil-light. That light, when on,indicates a total loss of oil pressure. When you turn the key on, theres is not yet oil pressure, so the light will be on.As soon as the engine starts, Oil pressure builds and shuts the light off. If the engine stalls, the light comes back on.That is normal.
2)Second;you can turn on a TV or an electrical motor, but you cannot turn on an engine.You can turn the key to "start" and the engine "cranks". If it fires up, you release the key to position "run" and it runs.When you finish your drive, you turn the key to "off", and it shuts off.So those are your three main ignition switch positions; Off-Run-Crank.
3)If the engine shuts off while you wiggle the key or lock cylinder without actually turning the switch away from RUN, then the switch is bad;replace it.
4) Yeah about that rotor;There are two metal ends in there; the part that is normally bent up and over to meet the coil tower when the cap is installed, and the other end, that distributes the spark to the various sparkplugs.The point is; the central part is supposed to be bent in an offset.Sometimes those ends are made of two pieces. If the distribution end is bent, it can send the spark into never-never land.If that is the end that was bent in your case; the rotor is junk,replace it.And the cap may have been damaged by such a bent firing-tip rotor.

Now as to the first "no start"; Since up to this point the engine had no history of stalling, I think it would be fair to assume the entire ignition system is fully functioning in the "run" position.And since it obviously cranks, that key position also works.So Ima gonna guess that; so long as the ECU is properly grounded,and that the rotor is 100%,that the first no-start was a fuel issue.And I'll guess flooded. I'll guess the carb percolated some gas into the manifold right at shut down.This may be due to a high float level(probable), or due to something stuck in the float valve(unlikely).

As to the second "no-start";Ima gonna guess it was simply flooded.Choke flooded.The vacuum break may need to be changed, and/or the choke element preload,reset.

In both cases I'm guessing.
So remove the ECU and clean the case ground and the mounting pad. Then prove the rotor is good. Also check the engine to body ground. Then I would check the float level and carb bowl vent.And finally the vacuum break, and choke thermostat preload.You will need a service manual, or perhaps someone else will chime in.

 

[Bill Crowell]

If I may make a couple of Wild-*** Guesses, I would suggest checking your ballast resistor and ECU.

 

[340doc]

Are you running a orange ignition box? I had some weird no start situations with one.

 

[67Dart273]

To add to above, most of you know, "I'm big" on testing, diagnostics so far as one can take that, as opposed to "throwing parts" at a problem

Now, "throwing parts" can occasionally be OK, if you have money, or the parts, but that isn't a guarantee that your spare parts actually work, either.

Throwing parts ALSO does you no good if the parts aren't the problem, IE bad bulkhead connector terminals, or other wiring troubles, etc.

So, testing.

===================================

First you need some "stuff."

Go to MyMopar and download the shop manual for your car, and if you like the aftermarket wiring diagrams over there. The ones in the shop manual, generally, are "more complete"

http://www.mymopar.com/index.php?pid=31

Next, you need a 12V test lamp, a multimeter, some alligator clip leads, and some sort of parts store inline spark tester

==================================

Try to "catch" the problem right when it happens so you can find it.

REALIZE that there is a different circuit situation created if you

A....Twist the key to start vs.

B....Get under the hood and jumper the starter relay

When using the key, the IGN2 "bypass" circuit is activated in the switch, which sends full battery voltage out through the bulkhead (brown wire) to the coil side of the ballast

When jumpering the starter relay, power is being supplied to the coil THROUGH the ballast resistor as when running, so that is DIFFERENT. Also, when cranking the engine, going through the ballast pulls the coil voltage down further.

==================================

Start by "not" bumping anything. Install your inline spark tester. "Rig" it so you can see it while twisting the key, like under the hood gap.

No Spark?

Leave the key "in run," go out and pull apart the distributor pickup connector. Take up the engine side of the harness, and tap the bare terminal to ground. Each time you do so should produce a spark

No spark? As above, clean and re-ground the ECU. Check for voltage at the coil + terminal "key in run". You should have at least 5-6V, and nor more than maybe 10-11

Check coil NEGative terminal. Voltage should be LOW, perhaps a volt or two. If the voltage is "same as battery" then the ECU is NOT conducting current. Might not be grounded.

Pull the ECU connector, the ballast connectors, and the distributor connector and "work" all of them in/ out several times to scrub the terminals clean, and to "feel" for how tight they are.

You can also, once the car "mysteriously starts" LOL wiggle these connectors for some insight. Also wiggle the bulkhead connector at the firewall.

==============================

Testing coils is difficult. They can "come and go" with heat. If the above tests show up nothing it might be a plan to swap a different coil

IF YOU HAVE a tach connected, suspect it. Try running the car awhile with the tach disconnected.

 

[Dodge72]

New day, sun is shining, looks like a great day to fix a Mopar. Let me update:

First off, it doesn't cost me anything to try to start 'er up this morning. A few pumps to the gas, and Varoom! Acts like last night never happened, started to warm up. Let it warm up for a few minutes before shutting it down. After about 15 seconds, cranked again. One crank and fired up again.

AJ, my lock switch is good. And I do know that the central part of that rotor tab is pre-bent in a certain way. What I mean is that it was literally twisted, and wearing that carbon tip in the middle down. Now, checking it again, it was in the same sort of shape I re-bent it into, close to the original shape. Now, On the rotor however are little gold specks, and on the rotor cap the raised edge where the carbon meets is worn through the paint and revealing this color. Some of it made it's way onto the distributor plates. That's not good.

As for the ECU....I'm running NAPA's house brand of ECU (a silver one). Where it is grounded we wore the paint off to bare metal so it could get the best contact. Now I've only had this EI for maybe two weeks now, and noticing some problems...

Intermittent misfire (not on any cylinder), especially when it's cold. Choke is operating. If I gently give it more gas, the misfires slowly go away, but occasionally I still hear one or two. Once it warms up they pretty much are gone. This might lead to a carb tuning problem, but this didn't happen with points?

Coil. Is there a electronic-ignition-specific coil I should have gotten? I just left my sort of new (4 months) coil in there. Seems to have worked fine.

I didn't have this problems probably the first week of having the system on my car. They seem to be getting worse. I'll be getting a new rotor and cap today, as well as pulling a spark plug or two. Thanks a bunch guys.


EDIT: Thanks for the info 67Dart273. I don't have a multimeter yet, but this is probably as good of time as ever to grab one and go test some electrical values...maybe I'll find something abnormal about something. Right now, I'll do some 'wiggling' lol! And no, I have no tach or any other aftermarket gauges.

 

[67Dart273]

The rotor problem might indicate something wrong with the distributor, or cap that is either manufactured wrongly, or installed "cocked." Check the distributor shaft for play.

Yoiu don't exactly need a specific coil. EG the coil in the points system should work OK. In fact, with the newer ECU which electrically only uses 4 of the 5 ECU box terminals, the factory "points" ballast could be used

This leads to a "trick."

You can keep your factory dist. for a spare. Let's say this all fails you on the road, but maybe the coil and ballast is OK, or that you have spares and have tried them.

You can pull the ECU connector off, and with no other changes, drop the old points dist. back in and wire up to the dist. neg terminal, and fire it up. This is of course a bit easier with a V8. Dealing with slant distributors has never been my favorite day, LOL

 

[TrailBeast]

If you still have the OEM pigtail on your distributor take it apart and crimp it a bit tighter.
I have had two cars acted like that from expansion and contraction of that plug.

 

[Dodge72]

I didn't get that much done today going back and fourth running errands in a different car (couldn't take the chance). I got a multimeter for this weekend and a new cap and rotor. I blew out the distributor the best I could of that gold dust and put it together. This is the old rotor, note the paint wear on the end of the tip and that gold dust:

I was able to, again, to fire right up. It ran a little rough, but of course got better when it got warmed up. I took it for a light drive through the neighborhood. In drive or reverse, not a single misfire like it would be in neutral or in park, nice and smooth. I parked in the driveway, shut it down, then fired it up again. Humming along, intermittent miss. Turned it down again, waited a few minutes, then fired it up without fail. Did a wiggle test on the ballast, ICU, distributor wire. Didn't seem to do anything, definitely did not shut it down.

Pulled a spark plug before the sun went down. Looks like a little oil leaking in, but I already knew that. I'll recheck their gap this weekend, maybe it'll help the misfires.

The distributor is used and so is the wiring harness; it got thrown in with my Super Six deal. What pigtail are you talking about? Is it the two wires on the distributor that goes into the harness?

 

[AJ/FormS]

That does not look like any slanty plug I have ever seen, and for sure not in a 72.IIRC the correct plug was a Champion RN14Y. What number is that?And where is the gasket?

A misfire in Neutral/Park, is sometimes associated with too much spark advance. As well, it could be contaminated fuel, a maladjusted idle circuit, a vacuum leak, plugs gapped too wide, or a too-high float level.

If she doesn't like to idle at 550 or less, I have found that the factory lash specs of 10/20 may be too tight. Mine is very much happier at .012/.013intake,and .023exhaust.But I run my engines on the hot side.So that may be why,I suppose.

The stuff at the rotor tip is of no consequence. When mine does that I just clean it up with a file and sharpen up the pointy bits.It may be a by-product of a very wide plug gap.I like to run as wide a gap as the coil will reliably spark, for my driving style.So I put on a coil that lights up the garage, and open the gaps to .045 to .060. They say a wide gap helps to light marginal mixtures. So I lean out the lowspeed circuit until it misfires at 60mph,then richen the poor girl up,a tad.You might be surprised at the mileage a slanty is capable of.And it don't hurt power one bit.

The pigtail is the two-wire power cord that hangs off the distributor. It's about 7 inches long and terminates in a connector, which connects it to the ignition harness and eventually finds it's way to the ECU.The two ends are polarized so that you cannot connect them up wrong.lnside the rubber-connector are the metal contacts that TB was talking about. The signal that comes out of the dizzy is extremely small, so the connection needs to be extremely good. Same goes for the other end where it connects to the ECU. Make sure everything is clean,dry, and tight.

 

[67Dart273]

That does not look like any slanty plug I have ever seen, and for sure not in a 72

A misfire in Neutral/Park, is often associated with too much spark advance. As well, it could be a maladjusted idle circuit, a vacuum leak, or a too-high float level.

I think camera or the site photo software has distorted the view

 

[Dodge72]

Nope, they are the NGK ZFR5N's. They've been recommended many times over on Slantsix. I believe they are factory gapped at .035", which might be a little too tight in retrospect. I'll be regapping them wider to see if that helps. My valve lash I believe I did at .011 intake and .022 exhaust.

But I still do not understand why it refuses to fire. Certainly it can't be the spark plugs that makes it refuse to run? I've give the carburetor a once-over too just to see if everything is up to speed.

 

[67Dart273]

Well like I say "do some tests". Check spark at the coil, which will eliminate the distributor cap, rotor, wires and plugs

 

[Bill Crowell]

Pick up a Lisle (neon bulb) spark tester or the equivalent. They're pretty cheap. Then you can watch the spark tester from inside the car while you crank it.

 

[mguner]

My 72 Charger had an issue like yours and a wiggle test on the firewall confirmed a bad connection to the spade on the black wire with yellow tracer if my memory is correct.....

 

[TrailBeast]

The distributor is used and so is the wiring harness; it got thrown in with my Super Six deal. What pigtail are you talking about? Is it the two wires on the distributor that goes into the harness?

Yes, the two wire plug coming from the distributor was the one I said to check.
That plug you posted looks like it's been pretty hot, or has ash on the tips. (can't tell)
Your timing isn't advanced too much is it?

 

[Dodge72]

Got the perfect time to test it again...in the cold and rain, in work's parking lot again. I couldn't find my points distributor which sucked, so I couldn't convert it back. All I could do was test.


I don't get it. I tested coil to battery, normal readings. Tested ballast, normal. Swapped ballast, nothing. Tested wires on the plug to the ICU. Normal. Tested while cranking...got 9 volts out of 12. That was probably the only abnormal thing. Fuel was getting in there. Finally, after an hour an a half, we poked the choke open a little to try. Fired up. Got it to warm up, and drove home.

On the last turn down my street though, it freaking stalled! Just shut off like nothing. I barely made it halfway on the driveway. Crank, crank, crank......Looked to the carb, choke was open now but not working. I pumped the gas and held my foot down about 1/3 of the way, crank, crank, crank.....I release the key back to run, and int fires up as I release the key. Put it in drive, drive it up the driveway, and stalls again. This time, I just removed the key and slammed the door.

I checked the pigtail on my distributor. It looks like a solid connection, no frayed or stressed out wires....I wiggled it but found no play.

Man, am I frustrated! I have half a mind to put points back in (if I can find my dang distributor) just to see if it solves my problem. Someone mentioned it might be crud in my fuel lines? My tank looks relatively new, definitely not original.

If I can find that it will run, I will try the wiggle test again on the firewall and check my timing.

 

[AJ/FormS]

Crank,crank,crank,release and fires up; is classic bad ballast resistor

 

[Dodge72]

I thought a bad ballast was crank, crank, fires up, release key into the' run' position and it dies?

 

[67Dart273]

I tested coil to battery, normal readings. Tested ballast, normal. Swapped ballast, nothing. Tested wires on the plug to the ICU. Normal. Tested while cranking...got 9 volts out of 12. That was probably the only abnormal thing. .

What you wrote here, except for the 9v tells me exactly nothing. You need to detail "what" these tests are how you did them and what were the results

Where did you measure this 9V? At the coil? Is this using the key to crank the engine? To "finish" this test you need to do like so:

Measure at the coil cranking, using the key to engage the starter. Voltage?

Now move your meter to the BATTERY (or starter relay large battery post) and repeat the test. There should be just a few tenths of a volt different. That is, let's say the starter relay read 10 1/2--11V but your coil read 9V. That is a problem.

"When it quits" do some of the tests I detailed. Wiggle the ess ech eye tee out of the distributor connector. This connector has almost zero power going through it. It's a VERY low level signal, and if there's corrosion in there, it won't work. Working the connector "many times" in and out "scrubs" the terminals clean. I'd work it in/ out about 8-10 times.

Also you can put your meter on the distributor connections while disconnected, and crank the engine. With your meter set to low AC volts, the distributor pickup should generate about 1V AC

Inspect the distributor, wiggle the shaft for wear. Look carefully for rust and debri on and around the pickup, reluctor, magnet. Look for damage due to striking. Measure the resistance of the pickup. Should be 150-400 ohms or so. Should show infinity to ground.

Do the "tap" test I mentioned earlier. With power on, tap the engine harness side of the dist. connector to ground. The system should generate one "snap" spark each time.

"If you feel you must" put points back in you can EASILY do that with very little effort. Simply unplug the ECU connector, and disconnect the coil NEG terminal. Install the points dist, and hook the dist. wire back up to coil NEG and re-time.

 

[Dodge72]

Alright, so from positive on coil to ground, I got a~6V. From negative coil to ground, I got about 3V. While cranking, I did get about 9V from ground to positive coil. From the ballast resister to ground, I can't remember the exact values but one side has full 12V and the other side halved at 6V.

When I got the distributor, there was a tiny little play in the up/down movement of the shaft. It couldn't have been more than 1/8th" play, nothing major. I also noticed there was a little surface rust on the reluctor's 'points' if you may call it that.

I should also mention that when it was in the driveway and I was trying to crank it, I smelled a burned oil smell while cranking. It went away once it fired, and when I stopped cranking.

Tomorrow I'll do that "tap" test and check for resistance values on the distributor itself. Fortunately, it'll be warm and sunny tomorrow!

 

[MIKERP76]

check your power wire to the coil bypassing the ballast and check your bulk head connections as well.

 

[67Dart273]

9V is getting kinda low. Again, you must check cranking voltage two ways, at the coil POS and at the battery. If the battery is clear down to 9V cranking it is either weak or nearly dead, or the starter is pulling excessive current.

The 3V at the coil NEG shows the coil is drawing current through the ECU which is good

I recommend you remove the box, scrape the bolt holes and ECU flange and remount. The ECU MUST be well grounded

Lesssee if this still works

Here's a post I made about the simplest way I know to get across testing the ECU/ ignition parts

http://www.forabodiesonly.com/mopar/showpost.php?p=1970917976&postcount=6


You need a coil, the ECU and the distributor

Lay it out on the bench. Follow the diagram. Find the two distributor pickup terminals on the ECU. Hook them to the distributor

Hook the ECU case to battery NEG

Coil does NOT need grounded

Distributor does NOT need grounded.

Hook coil + to the power lead terminal on the ECU. Get a clip lead hooked there and let dangle. This is your battery "hot" when you are ready

Hook something from coil "case" to a probe for testing spark.

Hook up your power clip lead. Twist the distributor shaft while holding the test probe near the coil tower. The thing should make sparks

If not, unhook distributor. Take first one, then the other pickup clip leads, and "tap tap" ground them at the battery connection. Coil should make 1 spark each time you do so.

If not, try another coil. If that does not fix it replace the ECU

IF you hook it all up and it WORKS, then there is something AFU in the car harness. SUSPECT a bad ECU connector OR a bad DISTRIBUTOR connector
=============================================
This is all you need to test the basics of the ignition. You can easily test the ballast separate. A battery, the ECU, distributor and a coil, and of course some test leads

Below, the basic diagram for a 4 pin ECU

Below, the wire for testing spark. I use my 12V test light. No, LOL the spark won't blow up the bulb

Below, the ground connection. ALL you need is one wire from batt NEG to the ECU case

Below, the two distributor connections. In the car these are polarity sensitive, but for testing does not matter

Below, the coil NEG connection

Below, battery PLUS connection, one wire to this terminal of ECU and jumpered over to + side of coil

Below, all hooked up and ready to test (except for battery ground). Should produce sparks at least 3/8" and typically 1/2" long

Below, distributor "one wire" test. I have removed the other distributor wire for simplicity. Take the bare connector end or this clip lead (the yellow) and with everything hooked up, ground it repeatedly. Each grounding should result in a spark (In this photo you need to hook up the ECU ground wire, I left it off for the photo)

__________________

 

[Dodge72]

^^^ That looks very useful 67Dart273, thank you. Definitely will get the time to double check all that to make sure it's all solid. Just wondering, where did you get the little wires for the ECU with the alligator clip ends?

I've been thinking about it too and I know that some of my splicing is piss-poor at best. I did two splices on the conversion like normal, but all I had on hand were some cheap little crimps that barely fit. I also remember having to crank crank crank it while testing the EI and remember not having something plugged back in. I wonder if those little crimps are failing on me now, and get bumped or rattled ever so slightly as to lose connection. I'll take a look at those too (been looking at the 'how-to splice' sticky on electrical). Thanks for all the help.

 

[Bill Crowell]

I would say that the "won't start in ignition 'start' position, but starts sometimes when you turn the key to 'run" scenario indicates a bad ignition switch.