MTFCA Forum

The plugs are fouled on my ‘26. It hasn’t run right since I got it at the end of March. I’m trying to clean these as best as I can. When I look in the spark plug hole I don’t see much shiny metal at all. I assume I have some pretty decent carbon build up. What causes this? I’m no stranger to old cars and cars in general. I realize that too rich of a fuel mixture can cause it. Also not getting the engine up to operating temperature, but what else? How far do I have to drive it to warm it up?

Carbon is a natural byproduct of combustion, you will get carbon when everything is running as it should, and you will get more carbon when things are not running as they should. You will never be able to look into the cylinder and see anything shiny. You may or may not have normal carbon buildup. Carbon can be caused by oil working into the cylinders, too rich a mixture, or poor ignition performance. Oil in the cylinders is normal. Spark plugs made for a model T like Champion X plugs, have the grounding electrode to the side of the center electrode so oil can drain off and not cause fowling. Modern plugs have the grounding electrode under the center electrode and will get oil buildup and cause fowling in a model T. Excessive oil in the cylinders can be caused worn cylinders, worn pistons, worn rings, worn valves, worn valve guides, any or all the above. You may be suffering poor performance due to operator error, not managing the spark advance and the fuel air mixture properly. If Model T's are new to you, I would first put the blame on operator error, the proper use of the spark advance and mixture setting. Second would be an ignition tune up, and if you have coils, send them off to someone who can properly test and adjust them. Make sure the timer is set for spark at just past TDC with the spark lever fully retarded, and good Champion X pugs with the correct gap set. As to worn cylinder, pistons, rings, valves or valve guides I would hold off on those fixes for maybe years.

To the above points, I would add: Avoid idling the engine for extended periods of time. Avoid starting the engine unless you are going to drive the car, preferabley for 5-10 miles or more. Do not idle the engine more than a minute or two to warm it up unless the weather is very cold. It's a good idea to drive the car for at least several miles whenever you start it. More is better. The engine is happiest when running on the open road in high gear at about 30 to 35 MPH. Engines tend to accumulate carbon deposits when idling, when running short trips, especially in cold weather, and when running slowly under light loads. If I were you, I'd put clean 10W30 oil in the crankcase, clean and gap the spark plugs, and take the car out for an hour or two of driving. Ford recommended keeping the oil level halfway between the upper and lower test cocks on the crankcase. That's about 3 1/2 quarts of oil. The engine needs to run on all four cylinders. If cleaning and gapping the plugs does not get it to run fairly smoothly on all four cylinders , you need to find out why and correct the problem. It would be a great help if you could locate someone in your area who has Model T experience to check out your ignition system and basic adjustments, and to listen to the engine run, and drive or ride in the car and evaluate its performance. Problems with things like coil adjustment, the timer, wiring, and the carburetor can make a good engine run very poorly. Most of these problems, if they exist, can be corrected at very low cost. Coil adjustment is one procedure that requires special equipment to do properly.

Does your car have a water pump?

Yes, it does have a water pump. I cleaned the plugs last night and again this morning and checked the gaps. The gap was fine and was already at .025. This morning I drove to work (less than 2 miles) and it could barely get up to 13mph in low and eeked out 25mph in high.

If you have a water pump and a good radiator, I doubt if your engine got even halfway warm on a two mile drive. Your car probably needs the ignition system wiring and timer checked out. The coils most likely need to be checked out and adjusted properly. You may have carburetor issues. A few 2 mile commutes, even in a brand new Model T with a water pump would probably foul the plugs. That's very harsh conditions for any motor vehicle to operate under on any regular basis. A Model T in fair to good condition will start easily, run on all four cylinders, and easily reach speeds of 35 MPH or more in high gear. The engine should not emit significant amounts of smoke. Blue smoke indicates oil burning. Black smoke indicate a very rich fuel mixture. Fresh, clean gasoline is a must for any car to run properly. The federal crap sold today under the name "gasoline" can spoil very quickly under some conditions. Model Ts have a fuel system that is vented to the atmosphere, and that is not the best situation for ethanol-adulterated gasoline. A vented fuel system can allow ethanol-adulterated gasoline to lose quality and absorb moisture far more qucikly than a closed system will. You can use ethanol-adulterated gasoline, but use the lowest % ethanol gas you can get, and make sure it is fresh. Non-ethanol gasoline is the best choice, if you can get it. (And afford it)

TXGOAT2 wrote: ↑

Tue May 10, 2022 8:55 am

If you have a water pump and a good radiator, I doubt if your engine got even halfway warm on a two mile drive. Your car probably needs the ignition system wiring and timer checked out. The coils most likely need to be checked out and adjusted properly. You may have carburetor issues. A few 2 mile commutes, even in a brand new Model T with a water pump would probably foul the plugs. That's very harsh conditions for any motor vehicle to operate under on any regular basis. A Model T in fair to good condition will start easily, run on all four cylinders, and easily reach speeds of 35 MPH or more in high gear. The engine should not emit significant amounts of smoke. Blue smoke indicates oil burning. Black smoke indicate a very rich fuel mixture. Fresh, clean gasoline is a must for any car to run properly. The federal crap sold today under the name "gasoline" can spoil very quickly under some conditions. Model Ts have a fuel system that is vented to the atmosphere, and that is not the best situation for ethanol-adulterated gasoline. A vented fuel system can allow ethanol-adulterated gasoline to lose quality and absorb moisture far more qucikly than a closed system will. You can use ethanol-adulterated gasoline, but use the lowest % ethanol gas you can get, and make sure it is fresh. Non-ethanol gasoline is the best choice, if you can get it. (And afford it)

I was getting some black smoke last night. I suspect that this car was restored in the 70's. The previous owner probably bought it from that guy (in 2011) and it was probably not driven much before he bought it. He said, and you can tell, that he cleaned the gas tank out. I never use ethanol in my A, T, '55 Chevy or mower. Maybe one night this week I'll take it on a long drive (if I can stand the jerking, bucking, missing) and see if that helps.

First off let me repost my mantra for about the 100th. time: Take a compression test. both dry and wet. Do it with the engine cold, On a low comp engine like the T's a cold comp test will give you a more accurate reading for cold starting the engine. Write your findings down. Don't trust to memory. This test is the easiest thing to do to find out your engines internal condition. Rings and valves. If your burning oil and creating carbon that way you'll know about it damn quick. If it's satisfactory move on to fuel/carb adjustments.

First off let me repost my mantra for about the 100th. time: Take a compression test. both dry and wet. Do it with the engine cold, On a low comp engine like the T's a cold comp test will give you a more accurate reading for cold starting the engine. Write your findings down. Don't trust to memory. This test is the easiest thing to do to find out your engines internal condition. Rings and valves. If your burning oil and creating carbon that way you'll know about it damn quick. If it's satisfactory move on to fuel/carb adjustments.

Charlie B in N.J. wrote: ↑

Tue May 10, 2022 9:14 am

First off let me repost my mantra for about the 100th. time: Take a compression test. both dry and wet. Do it with the engine cold, On a low comp engine like the T's a cold comp test will give you a more accurate reading for cold starting the engine. Write your findings down. Don't trust to memory. This test is the easiest thing to do to find out your engines internal condition. Rings and valves. If your burning oil and creating carbon that way you'll know about it damn quick. If it's satisfactory move on to fuel/carb adjustments.

I guess I'm not doing things in order. I should. So, let me ask.....On a Model T you do a compression check cold? Why? Hand crank or electric? Also, I have a compression tester and an adapter to use on my Model A, but I don't have an adapter for the T. What do I need?

Scott, I don’t think I ever get to 13mph in low, could be wrong but I doubt it. Do you have a filter on your fuel line besides an original sediment bowl? Have you cleaned the screen in the sediment bowl? Have you cleaned the fuel line?
Ditto to the other advice concerning long Idles and adjustments. Just curious did you tighten the bands in the transmission or no? Does your T run on magneto or just battery? I remember reading you were working on the bearings in the front wheels, any chance you over tighten them? Just brainstorming things for you to consider.
If your coils are decent, if you’ve set the float in the carb correctly & have the mixture correctly set you should be able to surpass the 25mph fairly easy in a car but not a TT. Not sure what you’re working on. The bucking you spoke of in high sounds like a fuel supply issue which generally means it’s electrical ha, coils, commutator, wiring & switch are some considerations for that. Gosh half the fun is figuring out what’s going on & then solving it. Lastly my mentor told me that the way he cleared carbon out of the cylinder head was spraying water into the carb while running at a moderate speed. I did that once on an engine I was going to tear down anyway because of some other issues. I scoped and saw a significant amount of carbon on the pistons so what a better time to try his tip out. So using a spray bottle with plain water in it, I gave it a try. I didn’t do it long because of the engine condition but on inspection once the head was off, I could see that it seemed to be working. I’m not telling you to do this & I’ll let others weigh in but it was something that my mentor tipped me own and again he was right. Might be something to the voice of experience. I should have listened more but was young and dumb. Your mileage my vary. Good luck.

JTT3 wrote: ↑

Tue May 10, 2022 10:16 am

Scott, I don’t think I ever get to 13mph in low, could be wrong but I doubt it. Do you have a filter on your fuel line besides an original sediment bowl? Have you cleaned the screen in the sediment bowl? Have you cleaned the fuel line?
Ditto to the other advice concerning long Idles and adjustments. Just curious did you tighten the bands in the transmission or no? Does your T run on magneto or just battery? I remember reading you were working on the bearings in the front wheels, any chance you over tighten them? Just brainstorming things for you to consider.
If your coils are decent, if you’ve set the float in the carb correctly & have the mixture correctly set you should be able to surpass the 25mph fairly easy in a car but not a TT. Not sure what you’re working on. The bucking you spoke of in high sounds like a fuel supply issue which generally means it’s electrical ha, coils, commutator, wiring & switch are some considerations for that. Gosh half the fun is figuring out what’s going on & then solving it. Lastly my mentor told me that the way he cleared carbon out of the cylinder head was spraying water into the carb while running at a moderate speed. I did that once on an engine I was going to tear down anyway because of some other issues. I scoped and saw a significant amount of carbon on the pistons so what a better time to try his tip out. So using a spray bottle with plain water in it, I gave it a try. I didn’t do it long because of the engine condition but on inspection once the head was off, I could see that it seemed to be working. I’m not telling you to do this & I’ll let others weigh in but it was something that my mentor tipped me own and again he was right. Might be something to the voice of experience. I should have listened more but was young and dumb. Your mileage my vary. Good luck.

Reading this list I realize I haven't really done all that much yet. There is no filter. There is a newish rubber gas line going from the sediment bowl to the carb. I'd like to change that out to original although I doubt that it makes much difference. Never tried messing with the bands yet. It does seem to run (equally bad) on both battery and magneto. I do have a leaky exhaust manifold. I don't know how much of a difference that can make?

all internal combustion engines need 3 things:

compression
spark
fuel

Charlie is too modest. He has advised to do a compression check far more than 100 times. Do him a favor and check compression and tell him what it is.

Since your car runs, we know it has enough compression to run but not to what extent the compression plays in efficient running - knowing that will help with further diagnosis
post a photo of your coils, out of the coil box and then post a photo of the interior of the coil box
post a photo of your carb and the engine on the carb side
these photos will inform all of the excited guessers as to where to guess next

My general advice to someone in your position is to quit playing "whack-a-mole" and guessing at 100 years of poor or missing maintenance. Plan on spending the $ to purchase 4 rebuilt coils, purchase and install a wood or plastic kit into the coil box, buy a rebuilt carb, install new manifold gasket, buy a new timer and wiring and just be done with it. After spending about $600 and two weekends of focused work, the car will run.

I tell every new owner, whether they just bought a freshly restored car or drug it through chicken-poop to get it out of the barn, that they will end with a mandatory spending of around $1000 to make the car do what they want it to do and any money spent from there is usually discretionary

FWIW, if you're not in high gear by the time you're in the middle of an intersection after stopping, you're over-driving low gear. That is likely due to such poor engine performance that it is necessary, but 13MPH in low is wildly too fast. Once your car is running correctly, give up that practice.

Finally, resist the urge or advice from others to "remove the head and have a look inside". Here's a clue: it's black and gunky. There, I just saved you from a fair bit of work, two stripped threads in the block and a month of searching for an elusive head gasket in order to put it all back to where it was before you started.

Scott, the last part of your above post was funny and was basically what my mentor told me back in the day thus the “ spraying water through the carb” to remove carbon. “Don’t fix what’s not broke” as he would say but that’s when you had to go to swap meets to find used parts or beg local club members for their extras. Seems like yesterday but that was 40 or more years ago.

I suppose I do end up going in several directions at once! Seems that's the way I am these days. This week, when there is time, I'll do that compression check. However, I don't have that adapter. I think my kit has rubber ends? Will that work if I have my helper hold that in the hole? This test is done cold? Is it best cranked by hand or with the starter? (this car is a '26)

The reason I prefer comp testing the T cold is it gives a true reading as to cold starting. On a modern with 100 + psi per cyl. a 5 or 10 Lb. drop between cyls. isn't the end of the world. In fact you might not even notice it. On a T lets say an average/good comp reading is 40/50 lbs. Lots are 30/40 and lower. Any drop below say 25/28 will contribute to hard cold weather starting and real power loss. A hot engine might read higher depending on what's worn. (rings for instance). That higher reading isn't giving a true engine condition report as far as cold starting is concerned. Be advised this pertains to low comp engines like the T.

Did we ever find out what brand of plugs he is using???
Terry

Please, please, please read over Scott Conger's post at 10:28 a.m. again and take all of his advice on maintenance. (see below in red)

My general advice to someone in your position is to quit playing "whack-a-mole" and guessing at 100 years of poor or missing maintenance. Plan on spending the $ to purchase 4 rebuilt coils, purchase and install a wood or plastic kit into the coil box, buy a rebuilt carb, install new manifold gasket, buy a new timer and wiring and just be done with it. After spending about $600 and two weekends of focused work, the car will run.

Also, take his advice transitioning between low and high. (see below in red)

FWIW, if you're not in high gear by the time you're in the middle of an intersection after stopping, you're over-driving low gear. That is likely due to such poor engine performance that it is necessary, but 13MPH in low is wildly too fast. Once your car is running correctly, give up that practice.

To answer your question, use the starter for your compression test. I remove all 4 plugs, then compression test each cylinder. Do NOT drop anything into the open plug holes!!!

I totally disagree with the spend money post. That’s not proper diagnosing that’s pi**ing cash into the wind. Learn how to figure out what’s wrong. Almost everything mentioned can be checked cleaned adjusted or repaired without large outlays. That’s what was done back in the day because they knew the value of a dollar. Read. Ask here. Talk to others in local clubs. Learn.

CatGuy- have you tried to find a Model T friend who has a good running T? I searched the forum and it seems there are 44 forum members in Iowa.

Your problem is most likely a simple fix that is narrowed down to a single item. How do you narrow it down and find the fix? Find a Model T owner who has a good running T, and swap parts.

You can quickly eliminate certain problems such as spark plugs, coils, timer, plug wires, coil box, carburetor, etc. Quickly eliminate the simple stuff and have the advantage of someone who has already been through what you are going through right now. A half day or less will cover the simple replaceable stuff, then if the problem still exists, then it’s up to you to dig deeper.

On a personal note, I had a fresh rebuild that would chug when I when shifted to high (as you described). The problem turned out to be a leaking intake gasket on #3. A friend and I re-torqued the manifolds and the problem went away.

For me, the fun is in the driving, not the fixing.

Catguy

based on Charlie's admonishment, do NOT get your coils rebuilt, do NOT rebuild or buy a rebuilt carb, do NOT replace the timer, do NOT replace ANY wiring. Try to run your car until frustration totally takes over. Pick and peck at random things, with no local expert help. You will totally regret having 4 coils which spark briskly; pine away for a carb which will not vaporise fuel, and enjoy roasting marshmallows on the smoldering wiring. FUN! And none of that fun includes driving! What a diverse hobby.

Then let us know when the car is for sale

Maybe Charlie will buy it and do a compression check. In all of the years I've frequented this forum, that is the ONLY advice I can recall him giving anyone. Ever. He does not kid when he says he's advised a compression check over 100 times to 100 people. When your only tool is a hammer, every problem is a nail, I suppose.

"Back in the day" the owner had a car which ran, and one day did not. That fix included the repair of the ONE system which failed, which in most cases could be diagnosed in a few minutes, based on the knowledge that the car was just previously in running condition. You do not have the luxury of such a situation. It's a lame car with who-know-what is wrong. I care not one whit if you follow my advice, but it is advice which will get the car running to a point where any further trouble will be easily diagnosed.

That's not what I said and you know it. Why don' you send him some cash since you seem to have some to toss around while telling him to spend his needlessly.

Scott's advice will fix the problem. However, I would do things in steps, rather than all at once. You may well end up spending the dollars anyway, but if you take it a step at a time, you should be able to work out just where the problem/s were. I would start with a set of rebuilt coils. If that doesn't improve things, move on to the timer. It will be a stepped learning curve which may serve you well in the future.

Hope this helps.
Allan from down under.

Dean Yoder lives in SE Iowa. Post a note here and maybe he can help you. He is not too far away.

Lordy if anybody can help him Dean can.

Sorry I was absent yesterday. I woke up feeling just awful. I think I overdid it mowing the yard Tuesday night. Here in Iowa it feels like it's July or August. Very, very humid and our cars are turning yellow from pollen! Anyway......here is the plugs the car has. In this picture I cleaned them up some. They were think with carbon.

Ed Fuller wrote: ↑

Tue May 10, 2022 5:31 pm

Please, please, please read over Scott Conger's post at 10:28 a.m. again and take all of his advice on maintenance. (see below in red)

My general advice to someone in your position is to quit playing "whack-a-mole" and guessing at 100 years of poor or missing maintenance. Plan on spending the $ to purchase 4 rebuilt coils, purchase and install a wood or plastic kit into the coil box, buy a rebuilt carb, install new manifold gasket, buy a new timer and wiring and just be done with it. After spending about $600 and two weekends of focused work, the car will run.

Also, take his advice transitioning between low and high. (see below in red)

FWIW, if you're not in high gear by the time you're in the middle of an intersection after stopping, you're over-driving low gear. That is likely due to such poor engine performance that it is necessary, but 13MPH in low is wildly too fast. Once your car is running correctly, give up that practice.

I do plan to take it easy on the car. I was just seeing how much of a difference it made delaying the shifting.

When cleaning plugs, it's important to get the insulator around the center electrode on the inside of the plug as clean as practical. This can usually be done by soaking the plugs in a strong solvent, such as B-12 Chemtool, overnight in a covered container. Then remove the plugs and gently remove the carbon between the insulator and the plug body with something like a toothpick or a sliver of hardwood. You won't get the insulator clean and white, but get as much carbon off of it as you can. Filing the electrodes on an old, worn plug can improve its performance, if done correctly. It can be difficult to reach down into the narrow gap between the center electrode insulator and the plug body, but that's what really needs to be cleaned. A clear, close-up picture of the cylinder end of your plugs might give some idea of their condition.