Beyond Frustrated...........RR won't start and run still!!!!!

[Mstone68440RR]

https://www.forbbodiesonly.com/moparforum/threads/68-rr-still-wont-start.144552/

Been having issues for some time now and became frustrated enough to give up and let the car sit for several months after many failed attempts at getting it running.

Above thread is a continuation of a previous thread and details all of the attempts to fix the problem. A few members suggested testing the coil pickup which ended up being the original cause of the car dying on the road and not starting. About a month ago I pulled my head out of my *** and was able to start the car finally. It idled great for 5-10 minutes so I shut it off. Excited to drive it again I started it up later the same day and adjusted the timing back to where it had been before.....no problems.

With plans to hit the local cruise night I got home from work the following day, started the car to warm it up, no problem. Shut it off, went inside, changed and then loaded a set of new wheels and tires in the trunk to have mounted and balanced. Started the car again and drove it out of the garage so I could air up the low rear tire. By the time I got back with the air hose the car died, figured it wasn't warmed up enough. Cranked it and no luck, tried again and again and acting like no spark????? Tested the coil pickup, still good. Tested the new coil and my meter suggested it may be bad so I bought a new one to try. No luck, took that one back and tried another coil, no luck. Pissed off I said F*&% it to the cruise and let it sit again.

About a week ago I tried yet again to get it ready for a car show coming up. Ended up testing the new MSD 6A using their websites tutorial and no spark from the coil, ok finally getting somewhere. I guess running a total of 15-20 minutes was just too much for this unit and it died?

Emailed MSD and they issued an RMA to return and replace the unit after explaining my dilemma.

So today the new MSD 6A arrived. I got home, installed it and sure enough the car fired right up! couldn't get it to idle and it was coughing and struggling to run smooth so I adjusted the timing a bit and tried again. Started and ran like **** still, so adjusted the timing a bit more. Started and ran like crap one more before dying.

One more adjustment and tried again, nothing.....................acting like no spark.....................AGAIN! Tested the new MSD and WTF no spark from the coil??????

Are these things so fragile these days? That is 2 new units and less than 20 minutes of run time! I have no idea what the next step is? I have no confidence in installing another MSD in the car if I can't even get the car running long enough to leave my driveway.

Is there anything I can test for to see if it is causing the MSD to fail so quickly? Something has to be wrong..........

Tempted to install a pertronix ignition and go that route.

Sorry for the long rant, just so frustrating to keep falling short of getting this thing on the road.


Mark

 

[68383GTS]

I had this same problem on my 66 Charger and a friends 67 GTX. On the 66-70 B bodies there is a main wire that burns up. It is the heavier gauge wire that goes through the bulk connector on the fire wall.

 

[68383GTS]

Come to think of it had to repair it on my dads Super Bee. Sometimes it would start and run fine. Other times it wouldn't start.Other times you could drive it a few minutes and it would die and it would not start.I would lose spark at the coil at various times.

 

[747mopar]

Have you tested the input voltage and ground to the MSD box? My guess is the problem is elsewhere like a bad wire or connection. While putting the new box in you likely disturbed a wire enough for it to make contact again then car fires, vibrates and pukes out again.

 

[Xp29h]

I know some think that msd boxes are suspect at times and I have had 1 fail. If you were buying from another site off flea bay I might say you’re getting an msd knockoff. But you’re not you wen5 right to the company themselves. I’ve spoke to many other guys about msd and concensus is they love voltage. If they don’t get it it can cause all kinds of issues. My guess is the system isn’t getting the voltage it needs continuously.

I didn’t go back through all threads but start right at the beginning of the power circuit. Trace everything and make sure all looks good and check with meter for good continuity. Old wiring can really piss a guy off. Check fusable links and everything at bulkhead inside and out as well. Going to be tedious but you’ll get it

 

[Frank Mopar]

I would run a wire from battery direct to ignition and see what happens. Heck the ground wire too just to be sure

I would also buy a Power Probe. This is the best electrical trouble shooter that needs to be in your tool box

Also check your grounds

I suspect bad bulkhead connection as mentioned by xp29h

 

[Billccm]

Pull the coil and msd ignition. Place on the bench and wire up for a spark test. Let us know what you discover.

 

[65wgn440]

If you have a ready to run distributor in the car, you can temporarily bypass MSD with a little wiring work.

 

[PurpleBeeper]

I'm with most of these guys.... wiring. Besides that large hot wire, I once had an issue where I kept burning up ignition boxes. Turned out I had pinched the blue ignition wire coming from the ballast resistor (or direct into the MSD) under the corner of the intake manifold.

It's likely wiring......it's in the ignition for sure.....check those 6-10 wires and you'll find the problem... my 2-cents

 

[Mstone68440RR]

Thanks for all of the replies everyone, probably going to purchase a Power probe as suggested to aid in finding the bad wire/s.

I am convinced that it is in the wiring as well. Is it safe to say the bad wire should be located in the engine bay?, or is there a possibility that I will have to dig into the wiring behind the dash?

I have already inspected the bulkhead connectors which looked to be in good condition ( cleaned a light bit of corrosion off of a few terminals, very minor)

I also have already bypassed the ammeter to eliminate that as a potential issue.

 

[5.7 hemi]

What kind of coil are you running? Hopefully not a factory coil.

 

[MoparLeo]

I didn't see any mention of type of ignition mods that have been done. Did this start out as a stock ignition set-up and started having problems out of the blue or did it start happening following any mods or adjustments ? Diagnostics is an A-B-C step by step process. Always go the simple stuff first, especially electrical. Battery fully charged ? All electrical and ground connections cleaned, dielectric greased ?
Power Probe is the best electrical friend you can have in your box. You can ppower up components on top of your bench. Failsafe against improper ground hook ups so you can't damage electrical components. Highly recommended.
http://www.fourforty.com/techstuff/ignition.html

 

[Mstone68440RR]

A little background on the car. I have owned it for 4 years now. Never had an issue with the car for the first 3-1/2 years. Died in the road late last year, no spark and no voltage to the coil so I thought that was the issue. Didn't work, and I did not find out until later that voltage is not present at the coil using and MSD ignition.

After a few attempts to get it running trying various methods suggested here proved futile the car sat for months in the off season as I was very busy at work and not motivated to work on it anyway.

Looking back, I think I now know what may have contributed to the issue I am now experiencing. Someone suggested to bypass the ignition and run a 12volt wire directly to the coil to run the car. I tried this method, again with no luck, to the point of running the battery down too low. In my haste to fix things, I left the wire in place while I hooked up the battery charger and forgot to shut off the battery switch. In hopes of getting another crack at starting prior to the final cruise night of the year. Well, as it turns out that was a big mistake, as I was in the shower my wife came in frantically saying my car was smoking! I quickly jumped out and ran to the garage and yanked the charger cord out of the wall, and shut off the battery switch before any thing caught fire.

At this time the coil was basically boiling out fluid, and two of the leads from the MSD were melting together in the wire harness. I cleaned everything up and inspected the other adjacent wiring and it looked fine, only the MSD wires were damaged.

So I bought a brand MSD 6A and a Blaster 2 coil. Still wouldn't start, so again it sat until I wanted to drive it to a cruise fund raiser in Feb. Another suggestion here was to test the coil pickup, which ended up being the culprit! Ordered a NOS kit from a member and replaced it only have screwed up the wiring sequence on the distributor by one location causing backfires and no start. Again, frustrated I let it sit for another month or so. Where I decided to pull my head out of my *** and fix it. figured out the correct orientation on the distributor and boom the car fired right up and ran like a champ, for a total of 15-20 minutes over 2 days which gets me to the start of this thread.


Obviously the near fire incident had to have caused some other damage to the original wiring harness on the firewall. I am ordering a Power Probe today and I have time this weekend to closely inspect all the wiring in the engine bay for any signs of damage.

Thanks to all who have chimed in and as soon as I find the exact cause I will update the thread with the fix.

Mark

 

[Billccm]

Well, I am no expert, but if it were myself in this situation I would pull the coil and MSD and set up a bench spark test. That eliminates the big components.

Then I would look for voltage drops at the coil. A simple test lamp at the coil during cranking can give you confidence you have good voltage and then proceed to the other items such as pick up, etc.

 

[Xp29h]

Looking at your “almost caught fire” post, a few thoughts come to mind. Just because wiring looks good, I may not be. Secondly, where you had done some wiring, the charging may have travelled into other wiring that is further away from suspect areas, places you haven’t even looked yet or possibly overlooked. Also, stupid question because I didn’t see it or missed it, but with msd you did bypass the ballast resistor? Sorry if I missed that part.

 

[WileERobby]

I suspect a loose/bad connection somewhere that's not easily evident, it seems that movement is the prime cause. Or a ground.

 

[Mstone68440RR]

A little follow up post since it appears that the car is running again..

After having 3 MSD units fail after only a few minutes run time, I decided to go back to the stock electronic ignition. I ordered 2 orange boxes, 2 ballast resistors, stock ignition coil to go along with the new voltage regulator already installed.

I had also untaped the entire ignition harness from alternator to bulkhead to inspect the wiring and all was good.

Installed the stock components, cleaned and brushed all grounds and made sure all connections were secure. Car fired right up and idled nicely as the car warmed up. Ran it for 5 minutes and shut it off. Had dinner, then came out and fired it up again and let it run another 15 minutes and everything seems good.


Planning on taking it for a drive after work today and getting a fresh tank of gas. Hopefully all goes well and I am back on the road with no issues.

Thanks for all the replies and suggestions, even though I still haven't found what might have been the culprit. I am going to do some short drives just to make sure everything remains working to get some confidence back in it's reliability.

 

[Johnpat]

Man,hope that does the trick!
I definitely know your pain,makes you doubt
your mechanical ability,hang in there.

 

[Billccm]

I wouldn't mind performing a failure analysis on your msd. I would think that the design would be robust to resist damage for up to 30V. For less than one dollar a VDR and a transient diode would make the design more robust.

 

[The Rebel]

Whew, glad your back up & running!