I am trying to get an engine started that I just bought a few weeks ago. Thanks to HAMB, I have established that it is positive ground. I have the starter cranking the engine by a wire to the solenoid. I have a hot wire from the battery to the coil. The rotor is turning and the points are opening and closing. I cannot get any fire. What do I check? This is all new to me. This engine is in a 55 Desoto. Its a 291 Hemi with a dual point dist. Thanks.
get fresh set of points, condenser, ballast resistor, cap, rotor, and coil. Or you can check those things out one by one and figure out what it needs, but it shouldn't cost too much. Thats stuff I always get when trying to get a long forgotten motor to fire. Have you actually pulled a plug to see if its got fire, or are you saying that it won't start?
If it's all original you should have 6 volt positive ground. Clean the points with a points file or maybe some crockus cloth. Don't use 12 volts on the 6 volt coil.....it's okay to run 12 volts through the 6 volt starter though.
After you know for sure that you have voltage to the points, pull the condenser lead so that it isn't touching anything. Using an ohm meter, check to make sure it isn't leaking. Unhook the coil and use an ohm meter to check it for shorts. If there is no resistance, it's probably shorted. If the coil is not the original, you may want to check it by bypassing the wiring to the ignition switch and just hot wiring it ( through the resistor ) and running just the ignition negative ground. Bill
If the coil wires were removed and you hooked them up like a negative ground system, the wires are probably reversed, take the one going to the distributer off and swap to the opposite side of the coil and try it again. Also the dual points on the early Hemi's didn't fire at the same time, they both have to be set at the high point as you turn the engine, you can not set them at the same time or one will be way off and won't fire at all. Last, a lot of old distributors ground out where the wire from the coil comes through the side of the dist, you can take the original electrical block out and run a new wire through a grommet. Good luck!
Thanks everyone. I have a 12 volt battery hooked up as a positive ground. I got a balast resister to cut the voltage down going to the coil.I replaced the condensor. I have fire now. I wired it 18436572 clockwise. It cranks and is firing now. It just wont start. The rotor button is pointed at the first cylinder on the drivers side. That is where Ive wired #1 plug wire.As i touch the hot wire, or remove it from the battery,it seems to fire when I break the contact. Ive put plenty of gas through it and it just wont hit. I have moved the dist around both ways . HELP.
You say there is a spark when you remove the power wire or drag it across the battery post. Turn the motor over by hand until the points are open. Now drag the wire across the battery post and see if it fires. If so, there is a short somewhere past the coil. Bill
Double check you've got it timed on the compression stroke (could be 180* out) check your point gap, If the spark plugs are firing at the right time you ought to be able to run it with coffee can dripping in the intake. What I'm trying to say is fuel mixture isn't as critical as proper timing to get a motor to fire up. Try choking it, retard the timing about 10*. is the distributor on the front or back of the motor?
my 54 desoto 276 is 6 volt negative ground, i have it sitting here right next to be on a stand i run it in.
Thanks everyone for the input. I have NOT got it to run yet. I wasnt able to get into the shop last night. Kids softball games come before anything else for me. I sanded the points with 120. Slid a dollar bill through them a few times to clean off the film. I pulled the number one plug out and put it up on the intake to observe the spark while cranking. It sparked one time as I touched the hot wire to the battery. I might pull the dist and put it in my vise where I can set the plug gap real close and be sure everything is working. I have the battery in it as a positive ground. I have a resistor in the hot wire from the battery to cut back the volts. Its smoked a few times. The hot wire is on the + on the coil. The one to the dist comes off the -. I am so ready to sell this entire car and two loads of parts if I cant hear it run soon. The cap and button look brand new. Points look new as well. It has sat in a heated warehouse for the last 25 years. Rebuilt and never started.
before you give up find a mechanic. sounds like something simple that your over looking. The spark plug shouldn't fire when you hook up the battery. If the points are closed, the cap is lined up to the specific cylinder and you disconnect the charged coil it should spark. thats basically how points work. the coil being connected to power and grounded through the points sets up a magnetic field in the coil that collapses as the points open and generates a high voltage from the other set of windings in the coil, and presto spark. for the amount of money it costs get a NEW coil, a NEW cap, a NEW rotor,and a NEW set of points. for $100 its worth not having to play guessing games if your not familiar with testing coils or knowing when a set of points can be re-used or not.
Thank you all for the help and advise on getting my engine to start. I pulled the dist out and put it in the vise so I could look it over real well. It had a wire off the lead side of the points and it wasnt making good contact. I cleaned and reset the points,and put the wire on it. Dropped it back in and it fired without turning over a full turn. Sounded good. Idled and took fuel fine. I must have it close. THANKS to all that offered up advise.
Glad you got it going. I hate to see anyone give up on these old engines. Too many guys have taken them apart only to watch them rust into junk behind the shed. Bill
Take it from me, that 291 is a FINE engine. With a bit of work, it can be a "Jack-the-Bear" engine...
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