What is causing my misfiring while driving ?

[Nevada dan]

Damn, how much diassably would be needed to diagnose that ?

No disassembly you just bring #1 up on compression stroke the timing mark on the balancer will still line up on the timing marks then take the distributor cap off and see if it’s pointing at #1
Simple quick and easy

 

[mopar 3 B]

No disassembly you just bring #1 up on compression stroke the timing mark on the balancer will still line up on the timing marks then take the distributor cap off and see if it’s pointing at #1
Simple quick and easy

And your checking what?

 

[Nevada dan]

If it’s not on the compression stroke it will be 180 out or at 6 so pull the plug out put your finger over the hole and you’ll feel the compression coming up then see if it looks right just to be sure

 

[Nevada dan]

And your checking what?

Static timing
Basic

 

[kiwigtx]

I believe NGK 5 forget the exact number. But they are the nice ones I'm pretty sure.

BP5S by chance?

 

[mopar 3 B]

If it’s not on the compression stroke it will be 180 out or at 6 so pull the plug out put your finger over the hole and you’ll feel the compression coming up then see if it looks right just to be sure

Think about it. If it was running fine how would it all of a sedum get 180 out?

 

[Evan Frucht]

This is so frustrating. I'm almost postive the problems will come back....

I'm not really aware of anything I might of done to "fix" whatever was happening but sure enough it was running good for the last 20 minutes or so. I even grew up the confidence to drive it around the block...

Now the issue is

I have to set my RPM to about 1600 in Nuetral to keep it running when I put it into gear. This is an auto trans.

So its goes from 1600 in NUETRAL
To about 900 in drive.

It doesnt seem right to me?

I have timing set at 15 degree initial.

 

[Evan Frucht]

When I was setting initial timing I did it with vaccum hose disconnected. When I reconnected the vaccum hose the idle speed and advance went up.

 

[Nevada dan]

I have a Dodge pickup with a 318 that would run fine and just shut down occasionally leaving me working on it from minutes to hours never really knowing how I got it running again I finally just put a MSD system in , distributor wires and 6AL box , never been happier it fires instantly every time and has never ran as smooth, been on it 10 years and never had a problem since, now I know it’s not original so it just comes down to how much of a purist are you

 

[Evan Frucht]

I have a Dodge pickup with a 318 that would run fine and just shut down occasionally leaving me working on it from minutes to hours never really knowing how I got it running again I finally just put a MSD system in , distributor wires and 6AL box , never been happier it fires instantly every time and has never ran as smooth, been on it 10 years and never had a problem since, now I know it’s not original so it just comes down to how much of a purist are you

Good to know.

 

[64fury74charger]

Just a suggestion here, timing chain “slack” can cause some of your issues. Pop the distributor cap off then observe the rotor movement as you move the crank pulley. There should not be any slop and if there is your timing chain may need attention.

 

[khryslerkid]

It jumps from running fine, to missing and struggling for a second, then itl run good for another 30 seconds, then misses a few beats kinda stumbles for a sec, then sounds ok for 45 seconds of running, then dies out. Then when I start it back up I'll ocassionaly get a backfire.

Evan this is typical bad condenser symptoms. It's exactly how they act like when bad. I've been through this several times with my Mallory dual point. Mallory has a bad batch floating around out there and replacing a bad one with another bad one can drive you crazy. I finally found another manufacturers condenser and haven't had any problems since.

Testing a condenser isn't that easy. Just taking a ohms reading won't completely tell that it's good. The continuity can be ok but after they heat up they can break down and even loose continuity all together. When cooled down they can gain connection again. This I'm thinking is where the back firing comes from. Every bad one I had ran like crap and backfired then wouldn't start again. And yes some were brand new.

I'd have to research how to properly test a condenser once again but it's much easier to just replace it with a brand new one and hope for the best. Try a different brand from the ones you've bought before.

 

[khryslerkid]

There videos on youtube. If the restiance grows when you connect a multimeter from terminal to housing. Its start at 10ohms and grow to 20 ohms over a few seconds and you watch the numbers raise or needle move.

This one shows how to charge and discharge a condenser using a multimeter. This isn't foolproof for the fact that a condenser can act differently under a load or under different temperatures.

 

[Evan Frucht]

Evan this is typical bad condenser symptoms. It's exactly how they act like when bad. I've been through this several times with my Mallory dual point. Mallory has a bad batch floating around out there and replacing a bad one with another bad one can drive you crazy. I finally found another manufacturers condenser and haven't had any problems since.

Testing a condenser isn't that easy. Just taking a ohms reading won't completely tell that it's good. The continuity can be ok but after they heat up they can break down and even loose continuity all together. When cooled down they can gain connection again. This I'm thinking is where the back firing comes from. Every bad one I had ran like crap and backfired then wouldn't start again. And yes some were brand new.

I'd have to research how to properly test a condenser once again but it's much easier to just replace it with a brand new one and hope for the best. Try a different brand from the ones you've bought before.

I did have a new one. An older made in USA. I swapped it in.. that was the last thing I did. And it got the car to start after not being start for a while.

Now sure enough it seems like the problems has left the room .... ( it will be back, I think )

It was running great for about 20 minutes last night...

My main problem now ( and I've had this problem semi consistantly in the past with this car) is that the idle speed drops extremely low when I shift it into DRIVE from NUETRAL. To keep the car alive in drive (800-900rpm) I need have my idle at about 1600 in NUETRAL

I have a hunch there is some sort if electrical load or drain on the system that is robbing the ignition system of power ( I have nothing to really back that up nor do I know how possible it is)

I'm very tempted to buy this kit and his coil
The HI REV 7500 electronic ignition kit. https://www.ebay.com/itm/For-MOPAR-...-/324465438501?_trksid=p2349624.m46890.l49292

And also my lights always dim when the idle speed gets below around 1200, I'm thinking the headlight relay kit that member here, crackedback, sells might solve some of my issues??,

 

[RJRENTON]

IMO....
Rick Ehrenberg offers many interesting Mopar items. Look at his eBay site for his offerings. He is also a member of SAE (Society of Automotive Engineers) and a contributor to several Mopar magazines. I believe you will satisfied with your selection, should you decide that way.
Re your lights dimming below 1200 RPM, it is possible that you have an open diode in the alternator. Especially if you sre using the origional Mopar alternator, which was rated between 37 and 42 amps output, this would possibly be your problem. The Mopar alternator uses uses a three phase full wave bridge rectifier circuit (3 positive polarity diodes and 3 negative polarity diodes) and if any one diode is open, the alternators output is reduced by half resulting in low voltage and dim headlights. Suggest that you look there for your problem. Just my opinion of course.
BOB RENTON

 

[Evan Frucht]

IMO....
Rick Ehrenberg offers many interesting Mopar items. Look at his eBay site for his offerings. He is also a member of SAE (Society of Automotive Engineers) and a contributor to several Mopar magazines. I believe you will satisfied with your selection, should you decide that way.
Re your lights dimming below 1200 RPM, it is possible that you have an open diode in the alternator. Especially if you sre using the origional Mopar alternator, which was rated between 37 and 42 amps output, this would possibly be your problem. The Mopar alternator uses uses a three phase full wave bridge rectifier circuit (3 positive polarity diodes and 3 negative polarity diodes) and if any one diode is open, the alternators output is reduced by half resulting in low voltage and dim headlights. Suggest that you look there for your problem. Just my opinion of course.
BOB RENTON

I've already replaced once the alternator, about a year ago I was having problems sort of similar to this. I brought my old alternator to a shop and had it tested. He told me it was charging fine but I ended up buying a brand new premium one from NAPA anyways... installed it, BUT NO CHANGE... it didnt fix anything.

Then out of pure luck I was able to figure out the problem... There was a short in my wiper motor that was making my lights really dim and causing misfire at low idle, bad idle. I guess causing some sort of parasitic drain on the charging system, and robbing my ignition system of voltage ( at least this was the conclusion I came to)

After disconnecting the wiper motor completely it made the car run a lot better...

This was all about a year ago. It was driving well for a while after that and now more problems. ..

So basically, I have a new alternator. And I have a voltmeter that plugs into my ashtray. Always shows about 14.5 volts running.... and my ammeter works exactly like it should (ever since removing the shorted wiper motor)

 

[Billccm]

Can you rig some wire to the coil + and tie back to a remote voltmeter? Then drive around while monitoring the coil input. I have an old a analog meter I use for this kind of troubleshooting as the meter will sweep with even the slightest dips.

 

[Red63440]

Back in the day I had a 46 Plymouth Coupe and if I turned the key off and then back on again it would backfire...have you checked the ignition switch??

 

[Billccm]

I think it's a wiring issue that is intermittent. It could be a weak or bad crimp, or a slight crack in the insulation causing a short on occasion.
Maybe try a parallel ballast path. Get a 1 ohm 10W resistor. Solder 18awg wire on each end and solder on alligator clips. When it acts up jump the coil + to the battery and clip in the circuit. See if that eliminates the issue.

 

[coloradodave]

It may well be an electrical issue, but have you eliminated intermittent loss of fuel? It sounds like it could also be a filter that allows some flow and then clogs with crap, causing the engine to die. Fuel tank sock filters as well as inline filters are famous for this, particularly when the dregs in the bottom of the tank are sucked up (running the tank down to empty isn't helpful). When the engine dies, immediately look down the carburetor venturies and see if the accelerator pump nozzles shoot two strong streams of fuel when you open the throttle blades.