The car is a '26 roadster, stock coils/timer for ignition. I recently rebuilt the engine/transmission, got everything put back together, and she runs great SOMETIMES. The #1 cylinder quit firing sometimes. After checking the points on the coils and adjusting them, swapping coils around, checking timing, I have figured out when it quits firing I can push the coil down and toward the engine in the coil box and it starts firing again. It looks like the contacts in the box are making good contact, but I still get the random miss. How do I fix this one?
Either rebuild the coil box or visit a lumber yard type store and buy a package of wood door shims.
Shims are really cheap.......
Do you have the cross piece of steel in the middle of the coil box? In some cases it has been removed which causes a gap. However, that gap would be more likely to affect numbers 2 and 3. The top of the coil box should have a spring riveted to it which pushes down on the coils. It is located between 1&2 and between 3&4. That should also be in good condition. The contacts at the bottom and the wood side of the coil box should be springy pushing toward the coils. They should also be shiny and clean. If that doesn't work, popsicle sticks make good wedges to hold the coils in place.
Norm
Do you have a lid for your coilbox? If not, get one.
The lid helps keep the coils in place and maintain contact by holding them down and putting forward pressure on the coils in coilbox.
When rebuilding the coil box buy all new parts for it.
You will be surprised how much better the engine will run when all the connections especially in the coil box are free of any corrsion, etc.
The original bolts were copper coated steel and after many years they loose their conductivity because of rust and whatever. Even after cleaning the originals you will be better off buying new ones. They are inexpensive and really help.
I've read advice from Ron the Coilman to be sure to reuse the original Ford Phosphor Bronze contacts inside the box. The reproduction contacts are copper plated steel, have no spring to them and break from vibration. Replacing the old rusty screws with new 10-32 x 2-1/4 brass Pan Head screws makes sense, though.
They should be soldered for best results - see these thread among others: http://www.mtfca.com/discus/messages/179374/200172.html?1301095099
http://www.mtfca.com/discus/messages/179374/249223.html?1322413399
I've been out working all day, just got back to check the responses. I tried some shims and didn't see any improvement. The steel cross piece is in place. I do have the lid for the box, springs on it look good. Must be time to rebuild the box! Thanks for the good advice and links to discussion.
If you're rebuilding the box, the Fun Projects kit is a good idea.
Before you rebuild the coil box, be sure to adjust all the coils with a hand crank coil tester or strobospark. Check the capacitors too. You might have an internal open or short inside one of the coils which becomes intermittant when you move the coil around. Another good test is to borrow some known good coils from another T and try them. If you have the same problem with the number 1 it is time to work on the coil box. It could even be a bad connection at one of the bolts where it connects to the spring contact or bad connection at the outside terminal where the wire is attached.
Norm
Randy, in your first post you mentioned adjusting points on the coils. Please understand I don't know a lot about coils but I can't help but wonder if you did the adjustment on a stroboscope or HCCT. You didn't mention one and the only time I've seen coils adjusted was while using a coil tester. Thanks for your patience, -Mike
I have awesome fresh coils from the Coil Dr. and mine does the same thing on the number 3 coil. Doesn't matter which coil I put in there, if it's not shimmed to squeeze it forwards a little bit it doesn't like to run. I rebuilt the box but did not inherit a lid or cross piece with the car. I just keep it shimmed and it's happy and runs great.
Seth, the cross piece needs to be there. You can download the drawing from Fun Projects website. Then make one to work.
10-4, I'll put that in the works.
I filed the points flat (there were some pits) and set the gap as the Ford book showed, using a feeler gauge. Anyone in the Vancouver/Portland area have access to coil tester?
I've swapped coils around and they work fine in the rest of the positions, just not in the #1. While testing on Monday I thought I smelled an odor of burnt wood, but they were re-paving the road by the garage and it was hard to separate the smell from the asphalt. Coils don't look charred anywhere, so maybe there is arc-through on the coil box?
"...I smelled an odor of burnt wood... so maybe there is arc-through on the coil box?"
Yes, exactly.
When I pulled my coil box apart, I did find 'black' around the 2nd coil .. apparently indicating some arcing had taken place. From what I've read here on the forums ... this arcing can even happen INSIDE the wood, and not be visible by us mere mortals. The plastic kit takes care of that. I opted for the cheaper wood rebuild kit at the time. Next spring I will probably join the plastic-coil-box-rebuild group. :-)
When rebuilding, as also stated here in the forums .. I kept my old contact strip hardware. I soldered the new through-the-firewall bolts to the strips, and cleaned up all the old strips. The new supplied strips (in the kit I got, at least) were copper, and appeared much less substantial than the brass original ones. The little buggar starts right up now!
Also .. if you have a box that HAD a center support, and doesn't now .. yes .. please add one. Shimming might work for a while, and you might get lucky and it could be a LONG while, but the box will spring out, and may then need another shim adjacent to it, etc. They need to fit pretty snug-ly!
Best of luck!
Dennis
I haven't looked for a few years, but at one time the cross piece for the coilbox was available from the vendors. Cost was minimal. Dave
After so many years of my dad trying to chase down an occasional miss and his stubbornness to believe it was the carb. I replaced the wood with the FunProjects plastic rebuild kit. Follow the instructions and soldered what needed to be soldered, I have no more misses and the car runs stronger. Best thing I ever did to the car.
Adjusting anything on a coil without a HCCT or Strobospark is a bad idea. Even adjusting the gap (which isn't all that critical anyway) can upset the balance between the lower vibrator and the cushion spring. Hopefully someone nearby will have what you need to get them adjusted for you. If not, PM me.
Langs sells the coil box cross piece for around 3-4 dollars.