I have recently installed new rings, ground the valves and seats, installed new manifold gaskets and rings, put it all back together and tried to start it. After a couple of adjustments I got it running but it seems to be missing on #1. Compression is 50# and I have good gas flow to the carb. When I ground out the plugs the engine slows on #'s 2,3, and 4 but there is no change on 1 and the plug is real dirty. Checked spark and it is good. Any troubleshooting help is greatly appreciated.
Sounds electrical - double check your wires so you're sure you're firing 1-2-4-3 from the timer. Swap your coils around and see if problem is still on #1. Problem might be the coil for #1. If it is, then when you swap your new dead cylinder will be wherever you moved that #1 coil to. If it's not wires or coils, then I'd double check the timer - make sure nothing wonky is going on there.
What plugs are you running?
Of course, it's one of those chicken or egg things, but why not clean the plug or try another one?
I didn't try anything last night but will swap out the plug for a different one. If no difference there I will try a different coil as well. Any tricks to getting the coils out of the box? They seem to really be wedged in there. The plugs that I am using are old but have good spark so I didn't replace them but that probably is a error in my part. Thanks again for all the info.
You should be able to grasp the two posts with the nut on top with your forefinger and thumb of one hand while maybe pushing up on the exposed side of the coil with you other hand's thumb or finger. Whatever you do, don't grab the bridges or you'll bend 'em and screw it all up. Sometimes you can "rock 'em" a bit to get them to come up too. Even if you want one from the middle, it's always best to start with the one on the far right end...the #1 coil.
Could be in the coil box. A rebuilt coil box can do wonders for the electrical system.
Sound like the coils haven't been out of the coil box in a long time.
The way that T Wrenn recommends is what I have to do in my 1919 to remove the coils.
Several years ago my 1919 Roadster had a intermittent miss that drove me crazy. I checked everything closely except the coil box since it looked good.
I finally pulled the coil box and installed new wood and new insulator bolts.
I started the car and boy was there a difference in the way it ran. No intermittent miss and a smother running engine overall.
John, you made a very good point about rebuilding the coil box. I ended up doing the same thing with my '25 TT firetruck last year and was amazed at the difference. I'm not amazed though that I totally forgot about that to suggest in my previous post...duuhhh. My mind's going. He could be getting some carbon tracking going on in the wood. I used the Fun Projects kit and ended up doing the same afterwards to my '15. Another great improvement there too.
I would try taking all the coils out first and clean the contacts on them and in the box. Then putting the coils back in the same place check. If the same cylinder miss fires swap the coils around, does it change?
Has any tune up work been done on the coils? google
"mtfca; coils" and learn more then you ever thought you could about 'em!
Fun Projects makes great products but if you can't step up to that level the wood kits still work or you could do as I did, made my own.
So I swapped spark plugs and still a miss on #1. So I swapped coils and still a miss on #1. My next step is to take out the coil box and give it a good cleaning. What do you guys mean when you say carbon tracking?
If the wood gets a little moist, electric current may travel across the wood instead of through a wire. The current burns a carbon path it will follow even after the wood dries out. This may cause the car to run badly. It's the reason for the FP kit, which eliminates it.
Steve, thanks for the explanation. So does that mean even if I have spark at the plug there could be something wrong in the coil box?
David have you laid the #1 spark plug on the head with it wired up and slowly cranked the engine over in battery, so you can confirm it is in fact receiving juice?
Seth has it. #1: is it getting spark to the plug?
Just an after thought, take hold of the spark plug wire where it attaches to the spark plug. If yo9u get a shock you know the plug is firing. If it is then there is something else wrong. If you don't get a shock it could be the coil or the coil box.
Keep us posted as to what you find wrong!!!!!!
. This is the spark on #1. The plug is wet when I remove it and the engine doesn't slow down when I ground out the plug with a screwdriver. Any thoughts?
Yes, even if you see a spark at the plug, that doesn't guarantee it's a good enough spark.
LOL Bill, I have been shocked lots of different ways. Nothing has ever hurt or quite shocked the mess out of me the way that accidentally touching a spark plug wire with my sweaty arm did. The engine was running on fast idle on magneto and I don't remember what I was fussing with under the hood, but my elbow touched the spark plug and bout came out of my shoes it zapped me so bad. My freshly rebuilt coil from Brent Mize was operating at peak performance. My arm hurt from my elbow to my fingertips for a little over an hour afterwards.
So yeah. Uh. Moral of the story: don't touch the plugs when they can be getting juice.
Bill, I think I will pass on touching the wire I have done that in the past.
Steve, thanks for the info I think I will take a look at the coil box next.
Steve's right. Just because a plug will spark laying on the head, doesn't mean it will spark under pressure in the cylinder. I think you are on the right track. Dave
Are you running high compression head ??
Thanks for all the info. Plugs are good, coils are good, coil boz seems good, but my wiring in OLD and I think that is where my problem lies. I planned on replacing the wiring at some point and now looks to be that time, probably will rebuild the coil box too. Are any of the wiring kits out there better than others and what is your suggestions on rebuilding the coil box. Is the non wood one the way to go?
Fun Projects kit for the box lining. Non-wood. But you haven't found the problem yet have you? You've not taken a compression test so you don't know the condition of the cyl. in question. You seem to have a spark at the cyl. so further diagnosis as to it's mechanical condition is called for. Not guessing and spending.
Charlie, no I haven't found the problem yet. I cleaned up some of the bold wire ends and that seemed to fix the miss for now but the wires still need to be replaced. As far as the cylinder condition it has new rings and 50# of compression.
Get or make a spark tester or otherwise devise a means of holding the end of the spark plug wire 1/4" away from a good ground and see if it will jump THAT gap. If so, then the problem is either in the plug or a mechanical problem. The 1/4" is important. It takes more 'umph' to fire the plug with compression in the cylinder than it does in free air. 1/4" gap in free air will require about the same amount of 'umph' as the plug gap under compression. More than 1/4" isn't good for your coil.
If you have spark at the plug, but you don't know how "hot" the spark is, then go to Tractor Supply and get one of these electric fence testers. If you have 4 or 5 lights light up, then your problem is not lack spark from the coils.