MTFCA Forum

Engine runs smoothly at idle. At half throttle or greater in high gear, I'm getting an intermittent skip that I can reduce by adjusting mixture on the NH Carb.
I'm going to check and regap plugs, check coils, check timer, and check the car running in the dark for sparking.
I have black rubber fuel line connecting steel line. I've drained the carb bowl and cleaned the sediment bulb.
What else should I look at?
Thanks!

Check the contacts inside the coil box. May have to wire brush with a Dremel, re -arch curve to increase spring pressure on all ignition coil contacts, and Dremel brush the three individual coil contacts.. is any coil movement detected when pushed from front to back or side to side,.... If so, thin wood shims may have to be placed between the coil and the metal part of the box to stabilize and increase pressure on coil contacts so connection is not interrupted .

I would also check EVERYTHING related to fuel delivery. Your carburetor bowl fuel level may be dropping at higher engine speed/load as suggested above.
If the problem is reduced or eliminated with a full gas tank, it might point to a fuel delivery issue.
Engine vibration could bring out problems in the coil box or related wiring at certain speeds. Coil box contacts or chaffed wiring problems may show up at certain speeds.
At higher speeds and loads, demand on the ignition system increases. Just about any issue with the ignition system could contribute to a miss at higher speeds and loads.

Valve clearance and spring pressure could be an issue. Too little clearance might cause poor valve seating at higher speeds and loads.
I had a car that had been running very smoothly under all conditions. It began to show a miss at hot idle and other symptoms, such as jerkiness at low speeds and generally reduced performance. Once it cooled off, the problem disappeared. The problem proved to be an exhaust valve adjusted just a little too tight. Adding a few thousandths to the clearance eliminated the problem.

Sounds like fuel level. The recommended setting is a starting point.
Set the fuel mixture for best running @ hi speed.
Go back to idle.
If you need to increase the mixture adjustment for best idle running, fuel level is to low.
If you need to decrease the mixture adjustment for best idle running, the fuel level is to high.

Assuming you don't have a flow problem, like a new viaton seat that hasn't been modified for OEM fuel flow.
You can test for this condition with a clear plastic tube connected over the drain body, less plug. Tie the hose up. Mark the hose for fuel level @ rest. Note if the level goes down during hi speed running. That would indicate a restricted fuel flow.

Professor... Here's hoping for better weather this week.

If you haven't already done so, look for vacuum leaks between the block and the intake manifold. What style gaskets are you using there?

Spark advance 4 to 6 notches at idle. Full advance at idle may give your problem skip.

Intake leak negative... used the rings not the one piece.

Advance may be too much at idle. Will check again in a.m.
when I get a new set of plugs installed. If no change, off to
ask a friend to put my coils thru his ROBO STROBE...

Last steps will be a carb swap if needed, and draining the fuel tank....

Coils checked ok.... on to other things....

Find someone in your area with an ECCT coil tester to properly adjust your coils for equal and consistent firing Time to rule out coil adjustment.

Cleaning a worn out timer may serve little purpose, what type of timer and what condition are the contacts in?

New Day having a bad day.
Dirty.

Coils checked by my over qualified and expert friend today on a Robo Strobe.
I have new plugs to swap, and a new NEW DAY TIMER to install. If. If that dosent fix it, then I'm also going to swap the NH out for a good rebuild. Draining the fuel tank is also a thought

Is that the timer that was on the car ??????????? That could definitely cause a "SKIP" !!!

Was and still is on the car. Only has 400 miles on it.
I used some 400 and 600 sandpaper to clean it up along with brake cleaner. Still runs like crap.

Check your spark plugs. I've had good response with.. 0.025"gap.... and check 100% continuity between center electrode on spark plug and spark plug wire terminal on top.

Will check spark plugs as you say.

Your New Day repop looks like Hell. You want not only to clean out the nasty-looking stuff, but also flatten it down enough to remove the divots. That may not cure the skip, but a bad timer can do it. It's hard to believe that has only 400 miles on it. Makes me wonder if there's something seriously wrong with the brush.


Even an original New Day can require a makeover.

Well, there's your problem! What Steve said.

Coils checked by my over qualified and expert friend today on a Robo Strobe.

A Novice with the correct tool can achieve results a seasoned expert can only hope to impervising with tools designed for another purpose. The ECCT directly measures the time a coil takes to fire spark with 0.000020 second accuracy. All other coil test tools measure average coil current (Amperes) flowing in the coil while firing hundreds of sparks. Amperes is Not time to fire spark! It's just an I direct approximation of how long each coil takes to fire spark.
This method works reasonably well Adjusting all 4 coils for the same average electrical current IF ALL 4 coils are EXACTLY the same electrically and mechanically.

Once you get your timer woes fixed, get your coils properly adjusted for equal and consistent firing Time using an ECCT to enjoy optimal engine ignition Timing performance.

Steve's comment about brush condition made me look at the picture closer. The brush surface looks like it's far from being smooth based on the scraping on the timer contacts and plastic.
If anyone close to me has an ECCT, please reach out to me.
Thanks as always.

Looks like the timer body plastic has melted & redeposited on your contacts or some kind of lube was used like Vaseline.
I am betting this is one of them soft repop timers. Original & the better repop new days don't do this.

Improperly adjusted coils will destroy a New Day timer VERY quickly. Even one badly adjusted coil will cause damage
New Day timers should never be oiled or greased. Oil leaking into a New Day timer will cause trouble.
The best way BY FAR to set up T coils is by using Mr. Kosser's ECCT device.

Dan - can you post a photo of the front of that timer ? John might be on to something !

The wear pattern inside that new day timer kind of indicates to me at least that the timing cover needs to be centered onto the camshaft. The wear pattern offset of a circle will give erratic spark plug firing.

Foggy fuel isn't helping any either.
More work to be done tomorrow.....
Checked a bunch of things today. Will start it tomorrow after more work.

Gert the timer problem straightened out and the coils adjusted, then drain all the fuel and replace with fresh. I'd add 6 ounces of MMO and 1/2 pint of B-12 Chemtool to the fres, full tank of gas and go for a drive on the road at moderate speeds. Stale fuel can gum valve stems and cause sticking among other problems. My dad bought a new lawn mower at a Fall sale. The following Spring, he put gas he had saved over the winter in it. It ran for about 5 minutes until it stopped with a stuck intake valve. I had considerable difficulty getting the valves unstuck and the tar-like deposits removed from the valve stems and combustion chamber.

About stale gasoline:
From what I've seen and read, all ethanol gas does not decay at the same rate. Weather conditions and how it is stored can make a big difference, and some gas goes stale a lot quicker than other gas. Hot, humid weather may be the worst. But high elevation may encourage evaporation of "co-solvents" and other more volatile blend fractions, and lead to decay, hydration, and separation.
Modern "gasoline" is designed for use in closed, non-vented systems and fuel systems that operate under pressure. A cool, dry environment is best for storage, if available. Taping over the vent might help keep moisture out of the tank and prevent some evaporation. I wouldn't plug it tightly. Some of the metals in antique fuel systems may contribute to ethanol gas decay. Old systems may have steel, copper, brass, solder, lead, iron and "pot metal" in contact with the gasoline.

Great news on resolving your timer and fuel issues.

and had my coils tested

Still highly recommend you find someone in your area with an ECCT coil tester and have your coils adjusted for equal and consistent firing Time; I think you'll find it well worth the effort.

Will do. Thanks!