Need help with 26 T engine running poorly

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Model T Ford Forum: Forum (old): Need help with 26 T engine running poorly
Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary W. Leonhardt (Gwleonhardt) on Tuesday, January 14, 2003 - 11:00 pm:

I have recently restored a 1926 model t touring car. I had the motor work done professionally and re-built the transmission myself. When I installed the motor in the car and first cranked it- it started and ran very well. Each day thereafter the car ran worse until it finally got where it backfired and ran as though it was running too rich. I thought it was the vaporizer I had rebuilt so I tried a carburetor - same problem which continued to get worse because sparkplugs and vaporizer plate as well as top of valves are coating with thick powder of carbon. Because it seemed that the car ran even worse on the magneto I figured it was maybe some problem in the transmission I rebuilt - maybe a short in the magneto. I finally got a newly rebuilt motor and transmission done profefssionally and installed it in this same car. Same exact problem. I really don't know where to go next.
It seems as though sometimes the generator does not show charge on the ampmeter - then next time I start the car it does - if I have the car at a high idle - car runs terrible on both battery and magneto. At a low idle the car will die quickly if I put the car over on magneto. I have checked and double checked wring - checked and double checked timer - could this problem be an intake leak? I believe the coils are working correctly
or is their anything I can look for there that might cause this problem. I am in Morganton, N.C. If there is anyone in this area that can help me.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Jablonski (Jabbotford) on Wednesday, January 15, 2003 - 07:17 am:

I believe the coils are working correctly
or is their anything I can look for there that might cause this problem.........

Have the coils been checked on a hand cranked magneto coil tester ?? Internal capacitors will break down & leak electrically giving poor spark, improper point tension will give double sparking & questionable amperage draw, point corrosion........the list goes on & on. Opening up the spark plug gap to .035 will give a better spark.

Have you checked magneto output ??

E-mail at your convenience.

Bob Jablonski


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Robinson, Salty Bottom, AL. (6volt) on Wednesday, January 15, 2003 - 07:17 am:

To me, and I'm rather dumb, your problem is symtomatic of fuel problems. The backfiring, the soot in the carb, the poor running at faster than idle speed all sound like a leaky intake manifold but it could be a sticking intake valve allowing gasses & fire to go back through the carburator. But why would you have the same problem on two "professionally" rebuilt motors? Did the "professional" assemble the two engines? Or, did you assemble them? Look for the common denominator!
I am attaching two photos. The first one shows the front of a motor. Note the two pan bolts directly under the timer. They are installed upside down in comparison to the other pan bolts. This allows the timer to rotate freely (at full advance)without grounding out on threads of the pan bolt. Very common problem on this forum for bad running T's!

image/pjpegupsidebolts
upsidedownbolt.jpg (38 k)


The other photo is an ignition tester that I made from an electric fence tester. It will identify quickly a firing problem and which cylinder its on. If 4 lights glow you've got good fire. Five lights--great. 3 or less will cause poor running.
image/pjpegignition tester
spark_tester.jpg (22 k)


Another "common denominator" in your case is----the timer rod. Don't assume that the former owner had the timer rod adjusted properly. THE TIMER ROD must be CALIBRATED! (yes, I shouted)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Robinson, Salty Bottom, AL. (6volt) on Wednesday, January 15, 2003 - 07:37 am:

But wait there's more. I failed to give a reason for my shouting about the timer rod. A rod that fails to advance the timer ENOUGH causes a retarded situation that fails to properly burn fuel ( rich mixture, rough running, lack of power, black exhaust....).


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roland Palmatier, Durham, NH (Roland) on Wednesday, January 15, 2003 - 10:32 am:

Bill,

Please tell us the details on how to make one of those "ignition testers".

Thanks, Roland


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Robinson, Salty Bottom, AL. (6volt) on Wednesday, January 15, 2003 - 09:19 pm:

Spark Tester


Here 'tis: The electric fence tester can be purchased at Tractor Supply or any co-op. Most are black or yellow. The black looks like a model T!! It has 5 lamps the light up and it tells you how many volts are gonna light up that cow's behind.. Cost around $10.. There is a ground lead coming off of the tester. I soldered a clip on the end. Attach the clip to ground on your car, touch the other end to a spark plug. If you have fire 1 to 5 lights will glow. The more the better. If you want one already made up TTP has em.

I am not an electrically inclined person, but I know this thing works. I keep one in the toolbox of each T.

/image{spark tester}


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary W. Leonhardt (Gwleonhardt) on Thursday, January 16, 2003 - 02:01 am:

I am working on this car almost every night. Here is where I am now. I pulled the spark plugs and changed gap to.035. I bought a fence tester today. I could get the car to start but it would only stay running for 15 seconds or so. I pushed the spark advance alway up and checked fire at each spark plug. I bumped the starter to advance through each plug and found all plugs lighting up all five lights on the tester with the last two lights seeming somewhat dimmer.

I have another model t sitting next to this car in my garage. This other model t is a 1926 coupe and it starts easily and runs good. Since I am having no luck with the touring car, I decided tonight to try to find my problem by swaping parts or equipment. I have always suspected my problem to be a fuel problem so I took the vaporizer off my good running coupe (intake/exhaust -everything and put it on the newly rebuilt motor. Now I can"t even get the motor to start or even act as though it could start. The starter turns the motor over strongly but nothing. As a last thing before I stopped tonight, I took out a spark plug and poured a little gas in the hole. I put the plug back and tried again. This time the car fired a few times but still would not start. As the gas I poured in was used up the car again only turned over with out firing anytime. I pulled a pug added gass and tried again - same situation. It seems again as though I have a fuel problem - but I am baffled as to how this vaporizer just minutes before worked on my other car. I am not going to let this beat me. Another thing I have speculated during my work is the possibility of a leak at the intake. I took my time when bolting up the manifolds to be as sure as I could they were on properly with gaskets in place.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe (Litening) on Thursday, January 16, 2003 - 02:06 am:

Check to see if you muffler is plugged.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Jablonski (Jabbotford) on Thursday, January 16, 2003 - 06:34 am:

Sediment bowl & screen clean, free flowing gas thru gas line ??


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Aquina (Johna) on Thursday, January 16, 2003 - 08:57 am:

Have you sprayed any starting fluid into the carb? if this works, your problem should be somewhere in the carb to the gas tank, if it does not fire, and you are getting spark, timing could be the problem. I'm kind of new t T's, but not to engines. I'll put this out to the experanced T guys, Is there a way for the cam timing gears to slip if installed wrong? and can the key shear and allow the gear to slip, or could it have been left out? I always check a dead engine in order: Spark,fuel(good), compression, and timing and almost always find the cause. good luck
john


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Huson (Modelt12) on Thursday, January 16, 2003 - 10:38 am:

Gary and John:

A timing gear can not slip because there are two pegs on the cam shaft that goes through the cam gear. However if you have one of those phoney fiber gears they can eat up the teeth and throw it all out of time. You will still get good spark but it will just be at the wrong time. Disconnect gas line at the carb and let the gas run for quite some time. Do this for quite awhile so that you are sure you are getting gas out of the tank not just the gas line. If you are not getting enough gas through the line take your sediment bowl off and get a new one with a glass sediment bowl at Napa. There is a screen inside the outlet of the original bowls that give people fits. When you first rebuild your car it runs great but as dirt comes out of the gas tank it coats the screen until it won't let enough gas come through. I have seen this in Colorado happen time after time especially with flat landers coming to the moutains. They get enough gas to run fine on the flats but not enough to run in the mountains. Also install a 5/16 line and an inline shut off just in back of the carburetor but not in the carb. Good Luck!!!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By eric danielson (Ericdanielson) on Saturday, January 25, 2003 - 11:52 am:

Check the valves for proper clearance and smooth operation. I bought a T a few years ago that ran rough and after a short time, would barely run. I thought I had fuel problems-put a rebuilt holley NH on it and it made no difference. Then, I figured I had spark problems, put all rebuilt coils in it and it made no difference.

The longer I ran the car, the worse it got until it would not start.

I found that the supposed "expert" that had rebuilt the engine a few years before I bought the car knew nothing about fitting model T valves in an engine. The valve clearances were way off. I think you have the same problem.

There are two schools of thought on setting valves, one is to set them with a feeler gage, the other is to set them using a timing diagram. The feeler gage method is simpler and faster and will detect whether or not your valves adjusted properly. If you do not have adjusters on the valve stems, and most engines do not, the valve stems have to be ground off individually for proper clearance. Proper clearance for the valves is in the reprint of the original repair manual-I do not remember the setting for sure, but someone else out there has it I am sure.

Also, if you are starting and running at all on a 6 volt battery, get rid of it. Put a 12 volt battery in the car. Your coils will last longer and will have much more fire. Good luck.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John H (26tourer) on Monday, January 27, 2003 - 06:45 pm:

Get rid of your 6 volt battery? Only if you can't be bothered doing a proper restoration of your electrical system and coils. How a 12v battery will make the coils last longer is beyond me. If you mean it will make poorly adjusted coils with leaky condensers run longer before they die, yes you would be correct.
My car starts like a modern car with the proper 6v battery as the electrical system was designed for.
Amazing also how many people show you how original their car is and the painstaking efforts taken to get exactly the right parts for that model...and then you spot the 12V battery!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Swan (Kswan) on Tuesday, January 28, 2003 - 07:44 am:

Eric, I respectfully have to agree with Jon H above in the cranking ability of the car on 6V vs 12V. A T will crank just as fast on a 6 as a 12 volt system. You also failed to mention one important problem with going to a 12V system; a 12V generator or alternator.

It is true that a car will run better on a 12V battery than on a 6V battery, if one plans to run only on a battery. However I haven't seen a battery, 12 or 6, that will match a good hot magneto, coils notwithstanding. Bad coils won't perform on anything, 12 or 6.

Unfortunately the 6V system gets a bad rap and folks forget that millions and millions of cars ran on 6 volt systems for the first 60 or so years of the automotive industry. But, the 6 volt system of a T is quite adequate IF one is running a stock vehicle. If one intends to add other accessories such as extra lights, radios, trailer lights, etc, etc, and make modifications, then by all means go to a 12V system.

There are a few down sides to a 12V system but there are advantages as well. Those are the decisions of the car owner. Good luck to all, 6 or 12! Ken Swan


Top of pagePrevious messageNext messageBottom of page Link to this message  By eric danielson (Ericdanielson) on Sunday, February 02, 2003 - 10:05 pm:

I find the comments interesting about electrical systems, but my experience has been different than others. The 12V generator is not a problem because the model T generator produces the voltage that the battery provides. The only thing thatn needs to be done is to adust the 3rd brush so it does not produce more than 10-12 amps to prevent premature generator failure. I did not fail to mention the problem, as there is no problem finding a 12V generator-it is already in the car.

I have had T's that were great drivers, but with dead mags. Going to 12V on them has made a decent car out of them without having to do a mag rebuild. The points on coils last much longer on 12V than on 6V. No doubt that a good hot mag is the best bet, but, to the amateur, rebuilding a mag can be a bit overwhelming.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson (Coilman) on Monday, February 03, 2003 - 08:41 am:

Eric
The Model T generator is capable of 100 watts. If you allow it to charge 10-12 amps with a 12 volt battery you are significantly exceeding that.
If you leave it that way it will get very hot and it is a race whether the field or the armature fails first.
If you cut the charging rate back to seven amps maximum it will last much longer.
Ron the Coilman


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