Ignition Problem (technical- I need help, fellas)

1961 Ford Inline 223 Six, Mallory Dual Point Rev-Pol Distributor, Flattop Cap, Single Coil. Car runs strong when cold (I think I hear a slight miss sometimes). But after running about 20 minutes, under load she'll hiccup, run some more, then develop a miss, stumble badly, and run intermittently under load or higher rpm.

I did have a coil going bad- it was leaking oil out the wire hole. Replaced the coil, running better, but still has the symtoms when running hot/under load.

I've also replaced points, condensers, cleaned the lead wire off the coil and replaced the cap. Same problems.

Could it be the ignition switch itself? It has never been replaced. What are the symptoms of an ignition switch going bad? Diagnosis?

Thanks. Appreciate the guidance.

 

could be the ignition switch, or many of the other igition parts...or it could be a clogged fuel filter, line, etc

diagnosis? hard to do it over the internet. Connect a volt meter to the positive coil wire, with the meter in the car, go for a long drive, see if the voltage goes down when it acts up, if so the ign switch or ballast resistor or wiring could be bad.

 

Squirrel, I don't think it is a fuel problem because it definitely only shows these symptoms after getting warmed up. So I am thinking it is on the ignition side.

Motor has a 390 CFM Holley. I did pull the plug on the bowl, thinking it might be some trash in the jets. No change, so I'm thinking it's the ignition switch.

How do you diagnose a faulty switch? It isn't an expensive part from Mac's. I may just change that out to eliminate that as a possibility.

Other ideas?

 

To check the switch hotwire around it. Fit a jumper wire from the battery to the ignition side of the ignition resistor, This will carry the current that normally goes through the switch and all of the wiring to and from it through the firewall. Be aware taht you will not be able to shut the motor off from the switch until you pull the wire. The better way has been suggested, that being putting a volt meter on the +side of the coil and monitor there. If you find that voltage to the coil is what is missing then you have to go back through the circuit and check each connection and componet. I have had flakey resistors, and a bulkhead connector that was bad. I would also look for carbon tracks in the cap and rotor that may be bleeding the spark off.

lg
no neat sig line

 

plug wires.

 

Larry, since the problem only comes up under load and once the car is hot, how is the best way to run the test to simulate these conditions?

Randy, the plug wires are new. Less than 3,000 miles on them. And would it be wires since it only occurs once the motor is hot???

 

Sounds like a weak fuel pump or vapor lock. next time it does it pour cold water on it and the fuel line and see if the problem stops for a while.

 

I thought it sounded like vapor lock also, but it's pretty darn cold where he's at. It was my first thought though, and sure would be easy to check...

 

Well, today I've had three coils on the motor. The first one was obviously bad, so I replaced that one with a used one I had around the shop. With the first bad coil, it wouldn't even run down the road, but with the replacement, it would but would stumble after it got hot. Went to the auto parts store, threw on a brand new one and it ran the same as the first replacement.

So I'm thinking condensor or ignition switch. The switch is easy enough to bypass to check. I think that will be the next step.

And you're right. It never got out of the mid-50s today, but it's been doing this all winter and we've had a cold one. Ran like a champt this summer, so I'm a little doubtful of the vapor lock. Could be a fuel pump going bad, but I'd think the symptoms would show up whether the motor is hot or cold. These problems only occur once the motor is warmed up and running for 20 minutes or so.

Dunno. I'll figure it out. Now where's that thinking cap???

 

When you look at the engine does the carb have a lot of frost around the base plate? You mentiomed a four barrel, might be icing up in the venturis, esp if your manifold doesn't have heat from an exhaust manifols. Long shot but I have Had that happen to me.

 

Two ways
1. run the rig till it starts to miss/fail then attach a wire from the battery to the ing resistor. You can jump to the coil also but run the risk of burning points if you run to long. Minutes will be ok but hours is bad.

2. Run the test starting out with the jumper in place and if you go a bit without problems then you may have found the issue.

I also tend to think that you should not focus to tightly on the ignition. You have so many other places to look. Don't discount that the vent in the fuel cap could be plugged. When you start to run bad release the cap and see if you detect a "woosh' of air rushing into the tank. I also had a rig with a pinhole in the rubber line coming out of the top of the tank. It would suck air and it was a real bitch to find as it was not leaking fuel out, it just allowed the fuel pump to suck air instead of fuel.

lg
no neat sig line

 

Are you using a non-ballast coil on a car with a ballast? Might be cause for weak erratic spark.
Or, the other way around, may be overheating a coil that needs a good ballast...

 

1950Chevy, this model Ford did not have a ballast. The wire itself to the ignition switch provides the resistence. Consequently, it gets quite hot and the heat transfers to the switch. I understand that it is possible to add a ballast between the ignition and the coil to absorb the heat.

I'm thinking the switch is going bad. And I say that because there is another problem with it. From time to time- maybe every 10th time I go to start the car- it trips the starter then dies. No starter at all. Switch back to Off, then crank again. Since this is the original ignition switch, I know they go bad over time. With shipping off Ebay I just bought one NOS for less than $20. I'm going to replace it and see where that takes me.

Second, I know that I started with a bad coil. I'm thinking that the damaged coil, in turn, damaged the condensers, so I'm replacing them. I've already replaced the cap.

So new coil, condensers, and switch- if that doesn't cure it- I'm thinking vacuum leak maybe? Finicky fuel pump? A bad ignition wire? Dunno.

Larry, I hear what you are saying, brother. I'm thinking that it just might be something fuel related. I'm going to check the base of the carb for vacuum leaks, and I'll check that gas tank vent, too. Again, dunno.

Tough to diagnose over the computer, but I really appreciate the suggestions. Thanks.

 

Put me down for a condensor. I use a heat gun to check them, start the engine set idle cam on fast idle and start heating up the bottom of distributor where the condensor sets.....
Remember about half the condensors you buy are defective!! Buy a napa unit....

 

I had the same type of problem with my Comet last year, it turned out the fuel pickup was becoming clogged after a few minutes of driving. Once the car sat for a while and the crap in the tank settled it would run ok again.

 

See? there are a bunch of different possibilities.

Troubleshooting is fun, right

 

Squirrel, you definitely have the right attitude. If you get all worked up about it and get mad, you get no where. The car doesn't care. The car doesn't know where you grew up, or what school you went to, if your wife is hot, or if you have loads of money in the bank.

Troubleshooting is an experience in humbleness and displacement of ego. It is a wonderful exercise.

Really.

 

GMC Bubba beat me to it. My friend had the same problems you are saying you have, change the condensor. We took his dizzy to Bubba and within 5 minutes he had it fixed, Bubba is the man.

 

Bubba be da' Man is right!

I might have this old heap wired up incorrectly. Bubba picked up on the fact that it is a Mallory Rev-Pol. The distributor has dual points and came with the "two coils in one" arrangement. Since I could not find one of those original coils, I was running two separate coils, two condensers, two sets of points. I used the "hot" Mallory units. I was burning up points. Then I switched to one single coil, but still two condensers.

Bubba has suggested that I run 1 condenser and step down to a lower-powered coil that does not need a ballast resistor, but still has enough juice to fire the plugs. He believes the dual condensers through a single coil have burned up the points again. I'm rewiring the ignition and we'll give 'er a whirl.

He also thought I might have a problem with the ignition switch, but suggested what several others did- hot wire between the battery and coil. But rewire the dizzy and get the correct coil first. The ignition switch is a separate matter.

It's a learning experience, fellas. Everybody has to pay for their experience some way. But thanks to the HAMB, we've got people like Professor Bubba and you other gurus.

Thanks again, guys. We'll figure it out.

 

I think this is your answer. You mentioned oil coming out of one coil and others getting hot. You need to run the hot to the coil through a resister. I think they are 1.38 ohms or something like that. Just ask for one at a parts house, like NAPA.

good luck,

 

Bubba is the "DIZZY MASTER"....

 

Ck the secondary wires, old ones give out under stress.

 

Better yet,take it to someone over 60and a mechanic.

 

Well now, hold on. I've got a birthday in a month and it will be #57. Is that close enough for hot rod work? Don't tell me I'm too young to understand points and condensers. Why I can remember putting points in that VW Bug and learning on that ....you know the rest of that story.

On a more serious note, just this morning I was in the parts store and realized I no longer have a dwell meter to set points correctly. I asked Art, who is about my age if he had one. "What decade are you living in?" he asked me. "Nobody fools with points anymore."

He looked and found that he did not have one in stock. Looked in the inventory at the warehouse. "Discontinued, no longer offered" was the note by the dwell meter picture in his computer.

Read it and weep. Thanks to the HAMB, we're part of keeping something alive that the rest of the world just doesn't give a hoot about.... Better or worse, it is a breakerless (or better "pointless") world more and more these days.

 

Jim Linder, GMC Bubba, is the dizzy guru. He correctly figured that the oil-leaking Mallory-on-steroids coil I had been running damaged the condensers. Further, running two condensers on either side of the dual points was toasting the contact points. Once everything got nice and hot, it would stumble, stutter and shake and try and die on me.

Solution: Step back on the coil to an appropriate 3 ohm, low-power Bosch unit. Just enough to fire the plugs, but not enough to fry the points. Run both points through one condenser that Jim had checked on his test machine so we KNEW it was right. Check the points, make sure they are ok.

Did all that this afternoon, and the ol' 223 Inliner runs as good as it's ever thought about. Thanks, Jim.

What did I learn? Plenty. The ignition side of the motor needs to be as well-thought-out as the rest of the car. Bigger and hotter is not always better. In fact, here, it made things worse. All the components need to be matched, or they won't work too well. So if you are having ignition woes and car not running too well, find yourself somebody who is a maniac about ignitions. That person is GMC Bubba. Not only did he correctly diagnose the problem, he sent me the right, matched components to fix the car.

And threw in a bottle of delicious hot sauce that I had on my scrambled eggs this morning.

Life is good, once again, and the universe is at peace...at least in my garage.

 

That Jim is a pretty smart guy.

You should sign up for his next Ignigion class, I learned a lot.

 

Flt-blk, it is on my "To Do" list, definitely. Just waiting for him to announce when the dates are, and I am there.

 

Got the old heap running pretty well now. Multiple problems, which all got solved.
In addition to the wiring on the dizzy being just plain wrong and the coil going bad, turns out the voltage regulator wasn't really up to snuff either ( it was a cheap replacement from many, many unknown years ago). Battery wasn't the greatest either. Got that installed Friday. And some of the wiring from the coil back to the ignition switch was pretty flimsy. Got that beefed up and insulated.

Car runs great now. It's a wonder that with all the mucked up stuff on it that it ever ran before, and I took it on a couple of 100 mile + trips! Dang.

 

I'll second this, it's a great class. I had an opportunity to learn some things that I've been doing wrong for a few years.

 

sound alot like my truck.i have put all kinds of parts on it.new valves,giuds and seats because it had a dead cylinder.thats fixed.but now it runs fine when it is cold,but when it begins to warm up it runs bad,a little miss here and there for a minute or so then the idol drops a little it stumbles when you try to rev it up.i watch my dwell meter and the dwell starts change from 30 to around 37 at idol so i back it down and it cleans up a little but not much then it gos right back up.i figured my timing chain was streached witch it was so i replaced that to.today i ran it and i noticed the coil was hot when i touched it.it has a new coil from napa new wires cap plugs points.its a small block chevy 327 from 1965 how difficult could it be.this thing is killing me.