My 29 roadster began running poorly last week manly felt like a lose of power and like it was running on 6 1/2 cylinders I have installed new plugs n wires with the addition of a flame thrower coil (been wanting to upgrade for a while) runs better at low rpms like up to 2000 rpm, very smooth and can feel the power After that it stumbles badly, I isolated the secondary 97 and it was the same I pulled the distributor (crab style), now I’m not really sure how the advance work but I suspect that the advance may not be operating properly, I need an education of how this little devil works
Hopefully, someone who is a real expert will chime in, but I'll get you started. The "advance" on these is actually "vacuum brake". It is in the protrusion on the left side of your picture (which looks like it has had no attention for quite a while). Take the big cap off, and there should be a floating piston inside, backed up by a spring. The piston presses on a disc rotating inside the distributor, and the friction keeps the weights from advancing the timing under periods of low vacuum. Under high vacuum, the piston is pulled back, allowing the weights to advance the timing. There should be a tube connecting the intake manifold and the distributor that supplies the vacuum signal to the distributor. What could go wrong? The floating piston may be sticking. Freeing it up and lubing it may help. The spring could be missing, broken, or weak. The vacuum tube from the manifold may be missing or leaking. There should be a thick leather pad on the inner end of the floating piston that my be worn or missing. It acts kinda like the lining on brake shoes to increase the friction on the disc. (I procured some special 1/4 thick leather and made some of these discs for myself; I may have one or two extras floating around). The hex-headed screw on the end of the hex cap is for making fine adjustment to the mechanism when you get it working. That should keep you busy.
@tubman , thanks for your quick reply I can not find or see a tube from the manifold I will pull the end off of the vacuum brake
Maybe take a look at the cap and rotor as well? My recommendation is to gas that Pertronix and set up a distributor with a quality point set and condenser. Keyword here is “quality”. Haha.
The vacuum brake tube connects to the upper left edge of the front cover, then to the intake. I see two wires coming from your distributor. Where do those go? Do you have some type of electrical controlled ignition?
Having no experience on electronic conversions with these, I had no idea, but I think you're right. There are better ways to "start the fire", but you'll still need the advance working unless someone has come up with a completely computer controlled set up that works with only 2 wires and no sensors.
good eye Mr ripper, I may indeed switch this back to points but for now I would like to either find the problem or most likely suspect at this time. It has been my experience that the pertronics either works or you have nothing. I have removed the end cap from the vacuum damper and found nothing This thing has been modified and fortunately I can contact the original owner and find out what has been done to this distributor. I pulled the distributor apart and found no indications of a problem so Unless the module is breaking down I believe I may be barking up the wrong tree
Pertronix units either work or don’t work at all if it has failed. Your issue sounds like the problem caused by running the wrong coil for your module. Only run the coil Pertronix pairs with your module.
I'd do a compression check and inspect/compare your spark plugs while they are out. If all the plugs look fine, I'd install an exhaust bung and get an air/fuel ratio guage and see what it tells you. Doesn't have to be a permanent install.....except for the bung. I'd also check all your ground connections, and check your float level. Floats have been know to cause the kind of issue you have. Had a friend who crashed his airplane on its maiden flight after a 2 year rebuild because the reconditioned and certified carb had a bad float.
From what you say and I can see, someone has completely removed the vacuum brake assembly from that distributor. Henry Ford never wasted money on anything that wasn't absolutely essential to the vehicles operation. Get the Pertronix out and a vacuum brake back in. The way it is, it probably goes to full advance immediately, unless they screwed with the advance assembly as well. That distributor looks like a disaster. You would probably be better off getting a different one that has been properly set up. And no, I don't mean an aftermarket electronic unit, but a genuine Ford unit, properly set up on a machine designed specifically for the purpose. You might start with Michael Driskell at Third Generation Automotive in Tennessee; they have an excellent reputation. As I said in an earlier post, timing is important.
Whomever built that distributor needs to go back to Flathead school and learn how they work. Pertronix just replaces the points mechanism, the advance mechanism and vacuum brake need to be operational and working just as it was designed to work. When you pull the vacuum brake the advance mechanism will "flop around" and timing goes all over the place. BUT - if it was running well before (even if the advance mechanism wasn't correctly responding) and now it isn't, then this is not the problem you're currently chasing. I'd start with a rebuilt and tested distributor from Michael at Third Generation - you'll bolt it on, and the dang thing will work (and have the correct advance setup).
Those distributors are actually a very simple item. I would fix the advance brake and make sure the points are in good shape and adjusted properly. As far as disturbing any other adjustments, I wouldn't do that. These things were only correctly set up on a distributor machine. Make sure the leather brake disc is not too thick. It will not advance properly. It should just peek up above the raised rim on the piston. Glue the disc in with a thin wiping of weather strip adhesive. Actually, what you describe sounds like the classic fuel starvation syndrome. Check or replace filter(s) and blow out the lines. Check pump flow and pressure. I would send the distributor to the place mentioned by "Bored&Stroked in his post. Be sure you have the vacuum line connected. It won't work right without it. It goes from the carb to a hole in the timing cover and feeds vacuum into the little hole shown in the distributor body in your first picture. Make sure this hole is open and clean. These lines use a now obsolete line nut. Do not try to screw a modern nut into this hole. You'll ruin it. Nuts should be available from early Ford parts vendors. They are also the same as the nuts used on Model A vacuum wiper tubes. BTW: You don't need to worry about getting it out of time. The dist. will only go on one way.
Lots of good advice from Tub and Bored, and some other advice from people who didn’t read all the words, or maybe don’t know about flathead Fords. Just order up a rebuilt ‘42 distributor from Third Gen and bolt it on. Best answer.
When I isolated the second 97, it seams to get worse also worth noting the stumbling didn’t start until 3000 rpm earlier in the week. It has degraded It has a cheep piston style electric fuel pump, and I wonder if it is running slower (I can hear it but the engine drowns it out) or as stated a blockage in the fuel line
@Glenn Thoreson , all good advice I’m planning on addressing the distributor at a later date as for now I’m chasing the fuel and I know see that the distributor drive is off set like a model A Thank you and all the others that have contributed
On the fuel, start with pulling the tops off the carbs, seeing if there is any crap in the bottom of them and checking the float levels. It kind of sounds like a fuel starvation issue - which obviously the distributor did not cause. Since you have an electric pump, you can always pull the fuel line up by the carbs and using a gas can (and being extremely careful) - see how well the pump is pumping. I would only do this outside and use all precautions to not start a gas fire!
That gauge is for fuel economy purposes. It guarantees good solid fuel pressure - without actually requiring there to be any fuel in the system. Please send it my way . . . I need to save on gas! LOL
Why anyone would start chasing other problems when the distributor is in as bad shape is that one obviously is baffles me. Especially with the fuel pressure that is showing. Trying to solve multiple problems at the same time is a fools errand.
the plugs are showing lean and there has never been any popping out the exhaust or after fires I replaced that gauge and the needle never moved off zero It is pumping gas but not sure if it’s enough I have another pump, will check the line for blockage the only other thing is the pressure regulator I will address the distributor but not now unless the fuel system is sound I have contacted the previous owner to find out what has been done to it before I do anything with it. It worked fine and other than not being original and looking poorly I cannot find a reason why it shouldn’t work as before This engine always had black sooty plugs before
I checked the lines from the tank to the carbs and they are free of any obstructions I replaced the electric fuel pump and gauge at the manifold (used) I have zero psi at the manifold with the new pump, there is flow to the carb but the needle never moved. I have a Holley 12-804 fuel pressure regulator between the electric pump and the manifold I wonder if it is letting me down Anyone have any experience with these? I ordered a rebuild kit and a new 0-15 psi gauge
I have one of those regulators too but it has never stopped regulating. Is yours adjusted too low? You did notice the In and Out markings on the regulator, right? You do know that 83% of all carburetor problems are the distributor, dontcha?
I installed the new gauge at the manifold and there is 3 psi even at higher rpms evidently the gauge I replaced the magic gauge is bad next I will look at the carbs, check the float levels and look for debris in the bowl seams like I’m working my way to the distributor
The primary 97 float level is 0.70 the secondary 97 is at 0.50 Measured from the top edge of the bowl to the top of the fuel not sure if this could cause this issue What do yinz guys think
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