Some of you may recall my issues a few weeks ago with my car hopping and running poorly when going into high gear. I believe that was an intermittent coil causing it to run on 3 cylinders on load. While that was going on it was getting harder and harder to start and didn't run smoothly. Top speed is also down now. The only way i can get it to start at all is with the starter and a LOT of choke. Once it starts it sounds like its running a little rich with "splashy" uneven visible exhaust, can't really improve this with any carb settings warm or cold.
Here's what i've done to date:
All coils replaced with reference coils from Ron Patterson. Runs the same on mine.
Anderson Timer replaced with new TW, no change. Reset initial retarded timing point with new timer.
New wires, new plugs. no change but plugs getting sooty fast.
Carb fully rebuilt with viton float seat. Passages clean, float level set correct. Also just tried swapping with a known good carb that ran fine on another car, no difference.
Compression 40PSI cold and dry on all cylinders. presumably better hot.
Fixed slight intake leak. no change.
Hot air pipe, no hot air pipe, no difference.
New 6v battery (old one had a bad cell)
Runs about the same on battery or mag.
Fuel flowing freely, sediment filter clean
Steel timing gear, so no missing fiber teeth affecting timing.
If it was one cylinder with a spark or valve issue it should try to start on the next turn of the crank. Doesn't even want to start with the starter. I get one chug on the first pull of the crank sometimes and then it doesn't even try to fire.
This was a "one pull to start" car before all this started happening a few weeks ago.
I suppose the next thing would be to pull the head but I'm not really sure what that's going to tell me.
any more ideas??? Prize to the winner!
Ken - Just a thought here, but pull all four spark plugs and lay them on top of engine block, then crank engine over and hopefully observe all four plugs firing. If they all fire, then put about a teaspoon of gasoline in each cylinder and immediately replace the spark plugs and attempt to start engine. If you get just one strong "roar" our of engine and then it quits, you'll at least know it's NOT an ignition problem and you can concentrate on the carburetor and/or fuel system. Again, just thinking out loud here, but this little "test" isn't hard, doesn't cost anything, and won't take but a few minutes. Hope this helps,......harold
How's the coil box? The top should be on and pushing down on the coils. All contacts should be tight and in good condition making contact with the coils. Sometimes if you have a bad spark plug or if the wood in the coil box gets wet, the spark will find the easiest path to ground which is not through the spark plug. When that happens it will burn a carbon path through the wood. Then you will either get a weak spark at the spark plug or no spark there. One check which sometimes works is to start the engine in the dark and look at the coil box and wiring to see if any visible sparks are seen.
@ Harold: good idea, I will try that next.
@Norman: its good i think. the car has never gotten wet and the coil box is clean inside, however others have suggested that i could be getting carbon tracking inside the wood. I plan to remove and re-wood the box to ensure this isn't happening. However i will check the coil springs in the box top. I have been running without the top sometimes during testing and it didn't occur to me that the coils not only need to push forward but also down. thanks
I wonder if there could be a crack in the block in the port area, letting some coolant into the fuel charge. I admit this is unlikely.But,weird crap happens. My service department fought a problem with the usually bulletproof 4.9L/300 c.i. Ford six that had a casting flaw in the head, causing it too suck coolant in briefly and intermittently causing a massive cloud of steam out the exhaust.
That's why i am contemplating pulling the head. It seems if i was getting coolant i would also be getting white smoke and the coolant level isn't dropping, but maybe some sort of leak between exhaust and intake?
There would seem to be other signs with that problem such as backfiring through the carb and presumably i would have lousy compression too, which i don't.
I also did a leak down test originally which turned out ok.
Ken, unless you have coilbox trouble, which is possible, something really weird is happening. See if your coolant bubbles. This is indeed a hairpuller.
With everything you've covered, you should have found something. Check ALL of your wiring for bare spots. Check the coilbox for those crapolla copper contacts and get rid of them if that's what you find. Anyone selling that crap has an equal reputation.
... also check out the ignition switch for clean and tight connections.
We had a similar issue with a fresh engine,
I changed EVERYTHING, including the exhaust
what I overlooked was that ,although I had but 4 sets of NEW champion ,plugs in it , the problem
finally, because I ran out of new plugs, I put a 50 year old set in,
it has not miss fired in 4 years now
just a thought
Watching and listening Kenneth.
Mine ran similar; rebuilt carb, replaced tank and fuel, rebuilt all coils, replaced timer, Each made small differences. Now that the engine is (reluctantly) torn down valves sorta OK. Babbit issues everywhere. Camshaft specs are horrific. Rebuilding engine, replacing cam with a new Stipe, and adding a Z-head. Looking forward to better things. Li,e yours, mine was over-sold in terms of prior completed work. Frankly, my bad.
Ken, just for kicks, try this. Take out the plugs. Scrape and scratch the ground strap and the electrode with a pocket knife or similar. Then, gap the plugs real close, say. 015.Then try it. There may or may not be an explanation for this, but saw this done by an old timer at a tractor show years ago. The guy that owned the tractor was having similar problems to yours and this old man came up and did the above. The tractor owner said 'it'll never run like that'! And the old man said 'by God, you watch it'! And it took off and ran.
Have you verified compression and spark are present at the same time? Are all the valves opening and closing at the right time?
Had a similar problem after a rebuild. After trying everything under the sun, I discovered one of head bolt threads was pulled and water was leaking into a cylinder. No white smoke or other indications until I pulled the head.
P. S. I didn't see where you checked the torque on the head bolts. 40 ft lbs is good
Mine stripped at 50.
My roadster is currently undergoing engine removal because it was running on three cylinders. Compression checked all OK, BUT the exhaust valve on #2 wasn't opening much, if at all, because of a broken lifter. This is unlikely to be your problem, but worth checking.
I had the same problem when my 25 touring started running on just three cylinders. When shorting the spark plugs I found good fire on all plugs, yet when I stopped each coil by holding the points open while running I found that number four was the culprit.
Ultimately I found the problem was in the wood of the coil box. The fire was shorting down a tiny whole the burned between the layers of the plywood. You could not see the burned areas till the wood was removed from the coil box.
This may not be your problem but it is something to think about.
There's why I use the Fun Projects coil box kit instead of wood.
(Message edited by steve_jelf_parkerfield_ks on September 19, 2016)
I ran into a very similar thing about a month ago. What I finally figured out was that I had 6.35V tested at the new battery. I thought all was well. Once I tested it while I was actually cranking it over the voltage was dropping to 3.72. I hooked up a 6V lantern battery that I had and it started right up.
Mine was also running the same either battery or mag. It didn't make any sense to me but once I changed to a fully charged battery it cleared right up.
I've run coil boxes in the rain. Once they short out, that's it! Do as Steve Jelf suggested.
Any news? I'm fascinated by problems like this. As Richard pointed out, coolant around getting in from a head bolt that extends into the water jacket. That reminds me of a similar conundrum. Fresh rebuilt engine developed a problem.It would run fine until it got warmed up. Then would loose one cylinder at a time,popping an farting to a stop. Plugs slightly wet with coolant.Had great compression cold.We changed the head. Problem gone. The head had been milled so much that when it got hot it curled up in spots and leaked internally every way it could. Not saying this is happening here, but for future reference if anybody reads my posts. And, this engine ran good for some time before pulling this.
I've been known to remove and take apart a soaked coil box on tour and microwave the wood pieces to dry them and to find the carbon tracks. Once you find the tracks you can dig them out with a knife. The microwave will spark where the carbon is. You might not want to do it in the wife's microwave. Once you have the carbon out it won't spark anymore.
Yesterday I filled the tank with fuel. Shortly afterwards I was able to crank start the engine and it fired right up like normal. Today it was back to its reluctant self. I did completely disassemble the coil box today. I didn't see anything that looked like carbon marks.
I also removed all the plugs again, cleaned them, and set them on the block. All spark normally when turning over the motor with the starter.
I'm thinking this is fuel related somehow. I'm going to send off my carb for exchange with a new one.
What does your fuel tank look like? Unless spotless you might keep carrying crap through the lines to the carb. Or starving things caught in the screen.
But, Ken, you already swapped a known good carburetor and it made no difference.
And Ken says fuel flowing freely. Ken, any chance you could pull the mixture needle and post a picture?
I will vote for a coil box, I have one acting the same way. Ordered a fun projects box. As my Grandpa use to say, time will tell.
@jim: I'll try to pull the mixture needle tomorrow. I have not touched anything on this borrowed carb.
@ Dave: When I pulled the sediment screen a couple weeks ago it was as clean as could be. I am starting to wonder if I'm somehow sucking air with the fuel. I worked on someone's Nash that did that, I could see bubbles in his clear fuel filter.
Unfortunately my sediment bulb is not glass
@Roger: it's hard to see how but it's possible. I will order or make new wood inserts. Or maybe get "plastic" eek.
I suppose the coil box wood could be in question but it's the sooty plugs I'm thinking about and that wouldn't be the box. I was thinking a bad/worn or broken adjustment needle but you said you replaced the carb and what are the chances of 2 being bad? Heavy choke needed on the new carb also? can't get that sooting up bit out of my head.
I'll always go for the simple stuff first. Example: My T would start and run fine on Bat. but would not run well - sometimes not at all, at low RPMs on MAG. After much research and gnashing of teeth, I found that the contact between the MAG terminal on the hogshead and the wire was rusty and a bit loose. I cleaned it up and tightened it and my T runs great on mag at any RPM. I'm not suggesting this is your problem, but that sometimes the simple stuff is the issue.
Ken-the Nash with the bubbles likely had a vacuum fuel system, which can do all manner of weird things. I have become so aggravated with them I have riddled them with a.22 rifle. They were full of pinholes anyway.
Silly question but did you check your fuel tank? Maybe there is something blocking the pick up. You might have dislodged it when you filled the tank and after running it worked back into place.
The carbon tracking isn't always visible. Especially if the coilbox wood is plywood. The "juice" likes to follow the glue between the plies and makes an internal carbon track to ground. Spark plugs sparking at atmospheric pressure are no guarantee that they will fire at cylinder pressure, when resistance is higher due to denser air. It's then that electricity will take the path of least resistance, like a coilbox carbon track...
Bubbles in the fuel line on a Nash, which probably uses a vacuum tank, has no correlation with a Model T, which uses gravity fed fuel. Totally different. One sucks fuel and depends upon NO air leaks, while the other uses pressurized fuel and would simply leak fuel to the ground rather than suck air.
Yes, it has sooty plugs, that's what happens when it's badly miss-firing. Only firing every so often, as it's doing, lets fuel accumulate, creating a very rich mixture that makes soot.
Your initial bad miss probably has sooted the plugs, as I described above, and made a secondary issue for you. Clean the plugs but also realize that new plugs, with a porous bisque glaze on the porcelain will absorb carbon and sometimes be ruined beyond cleaning. Old time plugs had glazed porcelain that sealed them from contamination.
Are you CERTAIN that your intake manifold is sealing well against the engine? Did you use copper crush rings and glands? Did a crush ring maybe slip out of place during assembly?
All, I haven't had much chance to work with the car this week. I did look in the tank and it is quite clean, although the internal baffle prevents me from seeing the fuel outlet.
I get good flow out the sediment bulb as well as through the carb, however my borrowed carb regularly leaks when shut off, so I would really like to get another one put in.
I have not had time to make new coil box inserts yet.
For all your advice and suggestions!
Ken,....you mentioned that,...."starting to wonder if I'm somehow sucking air with the fuel?"
With gravity feed on the Model T, there is NO "sucking" in the fuel system, so this would not be an issue.
And then, I realize that someone like me, telling you what the trouble "WOULD NOT BE" is really of little value, right" (:^)
Oops! Now, after reading more carefully, Gus already said that! Sorry Gus,......harold
Further development. Tired of fuel leaking out of the borrowed carburetor, I removed it and put in the one I originally rebuilt (that at the time didn't change anything) To be fair I did check and adjust the float level, it was slightly low, maybe 1/16" and polished the mixture needle. Nothing else was changed.
Now suddenly i can get the car to start with the crank again. I still have to choke it for 3 turns cold, but its better, and good enough to take to Piquette tomorrow.
The reason i mentioned air in the fuel line was an old article i read years ago about an "air bubble" that could form in a fuel line with high and low spots. I had this problem on my '25 T. The line on the '20 is very smooth and runs downhill to the carburetor, so i don't think that's whats happening.
So I'm still puzzled, but happy. Hopefully it will do well on tomorrow's trip.
The car was a little hard to start this morning but ran great, probably put 60 miles on it today. During the many demo drives it ran very well, and would idle very low and even. Many free starts. After I got home and it was off for 2 hours in the garage I switched it to battery and it free started again. Never had it do that after sitting so long.
So while it may be fixed I'm still puzzled what caused the problem and change. The only thing I can think of it burned off some carbon today.
Thanks to all that offered help, parts and suggestions.