Sambuca, does not pull the hills like he once used to. At first I thought that it was do to someone turning the needle valve in or out, because I always tell the kids "Go ahead, you can get up it, ring the bell, toot the horn, you can't hurt anything. So I've been playing with that the last few trips, with no success. Friday it stalled when I stop at the mailbox. Yesterday I pull the carb off, took it apart, found some grit inside and on the needle valve stem. I clean in all out, pit it back on and the T ran better, but still lacked the power to pull MIlls Hill in high gear.
THANKS for your help.
Happy motoring, Warren
Here's a video of Sambuca pulling Mill's Hill in the good old days.
Happy motoring, Warren
i suppose running a compression check and making sure your exhaust is 100% clear would be my first steps in accessing the problem. Grit in the valves kinda makes me think they are not sealing properly. A compression test would pinpoint this problem/which cyls/valves are sealing improperly.
In this order...
Check that needle valve again for a score on it. They can be fixed or replaced if it is scored
I'd pull the screen on the sediment bulb...you'd sometimes be amazed at what you find and wonder how gas managed to pass
I'd do a compression check
I'd recheck timer mechanical timing
See my other post on 'rule of 6's' for setting a carb to match what your car 'wants' to do.
Hopefully with this list you hit a home run. After this list you have to start tearing into things, I think
Warren- I can only relay my own experience. I have a good pulling Depot Hack w/Ruckstell, but the ruckstell was rarely used unless following a slower car, which cause me to lose speed. At no time was there a miss, sputter, or any sign of a tuning problem.
Then, one day while on a tour in Indiana I noticed a severe lack of pulling power on hills, even though road speed was fine. A small hill cause shifting from Ford high to Ruckstell high, to Ford low, etc.
Once home we had a meeting of the Magneto University guys in my shop and we could not believe the cause.
The 2 dowels on the camshaft had partially dislodged, and had actually wallowed the 2 dowel holes in both the cam and the fiber timing gear causing the timing to be way off.
A new timing gear and a new camshaft installed and the hack was "better" the before.
There are many things which can cause a T to lose power. I have a few questions and then a few suggestions.
1. Is the head, ignition system and fuel system stock or modified?
2. Does the engine skip as it pulls. Do you notice a definite misfire?
3. Does changing the needle valve setting make any change in the performance?
4. Does varying the spark lever position change the way it pulls the hills.
5. How many miles on the engine?
Here are some suggestions.
1. Does the fuel flow freely when you open the petcock at the bottom of the carburetor? If not you have a restriction in the fuel line. Either dirt or if you have a non-stock fuel filter it is blocking the free flow of fuel.
2. Check the timing. With the lever all the way up, the spark should come just after the piston reaches top dead center on the compression stroke and beginning the power stroke. If it is much later than that, your timing needs to be adjusted.
3. Start the engine and run a little faster than idle and ground out the spark plugs with a screwdriver from the wire to the head one at a time. Does is slow down when each plug is grounded or is there one or more which does not make any difference? If one or more doesn't slow it down, your car is not firing on that cylinder. Next hold the tip of the screwdriver on the head and the shaft about 1/16 inch from the wire connection. Can you see a spark there?
If no spark, try switching to another coil for that cylinder and see if the miss goes with the coil or stays on the same cylinder.
4. Pull out all the spark plugs and lay them on the head. leave the wires connected. As you turn the engine over with the ignition to battery, does each plug spark in order 1,2,4,3? If so you are getting spark to each cylinder.
5. While you have the plugs out, do a compression check on each cylinder. Are the readings approximately the same in all cylinders and at least 50 lbs? If you find the compression low on one or more or on all of them, you need some engine work. You could have anything from a blown head gasket to bad valves or rings. If you put a few drops of oil in each cylinder through the spark plug hole and the compression rises, you have bad rings. If it makes no difference, you have either a blown head gasket or burnt or sticking valves.
I'm quite sure someone else will have more suggestions. These are all quite easy to do without any special tools other than a compression gauge. Repair would take other tools but you shouldn't take things apart until you decide what needs to be fixed.
Here's the deal: if it came on real sudden it's probably a fuel or ign. problem. If it's been sneaking up on you for a while it could be deeper. As stated a comp. test is in order.
Since you found dirt in the carb, the first thing to check is the sediment bulb.
You might try cleaning and or replacing the plugs.
I usually have to clean mine once a year or so. Carbon gets down into the center of the plug. With a sharp pointed object I am able to scrape a lot of carbon out and it usually makes it run like new.
To all who responded to my call for help Thank You. I apologize for not responding earlier, it has been a hectic weekend and I have not had a chance to look at the forum. I will tomorrow and let you know how I make out. Thanks again to all.
Happy motoring, Warren
I just had to replace my head gasket on my A had a half an inch gap in the head gasket on cylinders 3 and 4.
TRY THIS> Was able to detect it before the compression check by shorting the top of the spark plugs to the engine and there was no change in how it ran.
Norm, here are the answers to your questions:
1. Is the head, ignition system and fuel system stock or modified? Stock
2. Does the engine skip as it pulls. Do you notice a definite misfire? No, when running on flat and not steep grades the T runs great.
3. Does changing the needle valve setting make any change in the performance? I'm still adjusting the needle value (that could be the problem right there)
4. Does varying the spark lever position change the way it pulls the hills. I retard the spark just a little when pulling steep grades.
5. How many miles on the engine? It was completely rebuilt last summer (I know that's not the problem)
Other suggestions (I'm ashamed to admit that I just have not had much time to work on this problem)
Nathan, I do not believe it is bad compression or values.
George, I have not checked the sediment bulb screen, as I have a near full tank of gas. However I do plan on doing that after I use up most of the gas in the tank.
Bill, I don't think it is a timing problem or one with the magneto. When I switch from battery to magneto you can hear the engine speed up.
Charlie, it can on suddenly.
Bud, I plan on doing that when I have less gas in the tank to deal with.
Andrew, I do not believe it's a head gasket problem and when I short out each cylinder there is a good spark and the engine slows down noticeably.
Thanks again for everyone's help, I hope to be able to road test Sambuca tomorrow, so stay tuned.
Happy motoring, Warren
You said the engine was rebuilt last summer. Has this loss of power been since the new engine was installed? It might have a nice new engine but some gremlin got stuck in there when the switchover was made. Maybe the timing's different now so that"sweet spot" for the timing lever is not where it used to be.
Since you mention steep grades, and it seems to be running smoothly but lack of power, and since you found some dirt in the carburetor, I would suspect the problem to be in the fuel system. Your tank is under the front seat and so the fuel pressure is low. Any clog in the fuel line could cause it to starve for fuel when pulling hills. Try cleaning your sediment bulb. First thing to do is drain some fuel from the petcock. That might remove the problem If not, drain the tank into a gas can (best to do this when the gas has only one or two gallons). Catch the gas and then strain it through a clean coffee filter in a funnel. See what you get out of the gas. If it has a lot of particles in it, that might be the cause of the problem. If you have any other filter in the fuel system other than a sediment bulb like Henry approved, you could be losing fuel pressure and flow by restriction. Try blowing out the fuel line with compressed air.
If this doesn't fix your problem, then try more drastic steps such as compression test, coil tune-up, timer replacement, re-set the timing.
Signs of fuel starvation is the engine runs as if it is about to run out of gas, with a lot of sputtering. It runs smoother at lower speeds and less throttle opening, but when you open the throttle it will act like it is running out of gas.
It'll lack power if'n the float level is set too low.
It's easy to check that w/out pulling the carb.
Norman, I have drained some fuel from the petcock under the sediment bulb (nice & clean), also removed the float bowl (it was completely full, with some grit at the bottom). I believe the grit came from all the dirt roads that I have been driving, as I do not have an air filter on the carburetor.
Ken, when cleaning the carburetor the float level and action were fine.
Thanks again for all the help, it is greatly appreciated.
Happy motoring, Warren
Thank you Jim, for your help
You mention still fiddling with the carb needle screw. Did you see my 'rule of 6's' on another post? To me as long as anyone is still tinkering with mixture screw...you never know where you are and hope for some 'place' where it just all gets by rather than actually work. Meanwhile your shifting timing, changing plug gaps, etc.
start the car, 6 notches on both sticks...screw the carb needle CW 1/8 turn and wait 6 seconds, do it again slowly for as many 6 seconds as you need...until it sputters and before it stalls open it CCW by 1/8-1/4 turn. That is going to be really close based on everything else, while still in spite of everything else. Go for a ride on nice flat ground with your sticks where you normally put them, shift from low to high just like you always do, and if it sputters on shift no matter what you do on throttle,reach over or have a co-pilot open it CCW 1/8-1/4 turn...should settle right out in high....and still work real good in low with a nice idle. Set here, you 'might' need to open 1/4 turn for cold start and set it back to run.
Did we mention spark plug gap above in other post? You said new rebuild...where did you gap them and what are the plugs? Sometimes 0.025" causes issue at higher RPM! If you gapped them tight, you may want to try 0.030-0.032 before going on a further witch hunt.
Driving on dusty roads may allow dirt into the engine but will almost never produce grit in the float bowl. That has to come from the gas tank.
You mentioned you drained gasoline from the sediment bulb. Was it a good strong flow or just a dribble?
Question: Does the gasoline you drain from the sediment bowl pass through the screen or bypass it ? I don't have the traditional sediment bulb, but rather a tractor type bulb with a glass bowl, so I don't know. If it bypasses it, you may still have a fuel flow / grit problem.
Has the fuel line shifted in position so that it comes too close to the exhaust pipe or manifold? That might cause a vapor lock. www.mtfca.com/discus/messages/118802/142806.html
hello warren can I hear the bulb horn you got on your car here is my cellphone so I can hear the horns 8709741635
I hate mysterious "loss of power" problems. There are so many subtle things that can cause that. Slightly restricted fuel flow usually causes a high-speed miss (sometimes hard to detect). Coil/condenser going soft usually results in a minor backfire at speed (but also may be difficult to detect in the early stages). Bearing issues or other binding in the drive-line sometimes doesn't show at low (easy to check) speeds. Low tire pressure, slipping clutch, wind, and road grade can create the illusion of loss of power. Even Califunny seasonal gasoline changes can make a big difference.
However, Bud H talked a bit about dusty roads. About 24 years ago, my wife and I went on a Catalina Caper Tour. Most of that tour is on very dusty dirt roads. We somehow sucked enough dust into the carburetor, that on the final day of driving we had very little power. The gasoline flowed very well from the tank into and out the drain of the Holly NH, but the needle valve adjustment just couldn't make it run well. Following my preference to limp it now, enjoy the day, and fix it later, we just took it easy for the last few miles. Humble Howard did have to pull us up a short hill. He liked doing that with that race car of his. I managed to get the car onto the trailer and we headed home after the tour was done.
The next day, after arriving home, I backed the car off the trailer, and it barely climbed into my normal little driveway. Without doing anything else to the car, I put a spare NH (that was hanging on the wall in my garage) on the car. Fired it up, and the car flew up the hill like I was going for a hill climb time! After thoroughly washing out the carburetor (and removing some gasoline and dust dirt clods), I changed it back and it ran fine forever more.
Fifty other cars didn't have much trouble from dust sucked into the carburetor. Of course, some of them were, I am sure, smart enough to run air filters on those roads. But dirt roads can gum up the jet and cause power loss, if the dust gets into the wrong place.
Drive carefully, and enjoy, W2
John, what is the best time to call you so you can hear all seven of my bell, whistles and horns? Wayne Thank you (and all others) for taking the time to help me with this problem. I have just ordered a new set of spark plugs from Lang and they should be here tomorrow. I was on tour yesterday see (Model T tour to the Aviation Museum at the Manchester Airport) and old Sambuca run great during the tour, but on the way home when I got in the city, I had problems starting smoothly from traffic lights and decided that one or more of my spark plugs was not working correctly. Saturday I drained the tank and changed the fuel line, neither one was the cause of my problem. Wayne I always enjoy reading your post and find them very thoughtful and informative.
Happy motoring, Warren
THANKS AGAIN TO EVERYONE WHO TOOK THE TIME TO COMMENT.
I think I my have found the problem, I got my new plugs, from Lang's and installed them today. Then I went for a little drive and Sambuca seemed to run better. The #4 plug had a lot of carbon on it and the gap was between 0.30 & 0.34. The rest of the plugs looked fine and were gaped at 0.30. Why the back cylinder was all carbon-ed up I have no clue. Anyway I hope that takes care of my problem.
Happy motoring, Warren
It's possible that the #4 cylinder is an oil burner and that someone in the past increased the spark gap in order to keep the plug from fouling. In the future, you can try cleaning that spark plug when the same happens. Or it may be advisable to carry along one or more spare plugs clean and properly gapped, and a spark plug wrench so that if it happens again, you will have an easy fix.