2 wet “ish” plugs

Vanspeed

Vanspeed

Well-known member
2 wet “ish” plugs

Been driving my ‘36 LB for almost 5 years now and I noticed a very slight miss at idle recently. I do not know the history this engine as it was given to me by a shop owner that replaced the cars entire drivetrain with new. I inspected it and had the heads off. I is sleeved on all cylinders. I just did a compression check and it is: 1-4 105/100/100/110, 5-8 100/100/100/100. Cylinders 2 and 3 look a little wet but all other plugs look like coffee and cream. Carb issue? I don’t notice coolant or oil draining down when I check them every spring. Carb is a 5 year old English 97, distributor is one of the last ones Bubba built, ignition wires and coil were all new 5 years ago. This is what the 2 and 3 plug look like.
 

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Re: 2 wet “ish” plugs

KiWinUS said:
Looks oilish to o me unfortunately.
What plugs?
Click to expand...

NGK AB-6 plugs. I put all new plugs in it. All have nice spark. Just an erratic slight stumble when it is idling. Do not notice anything at higher RPM’s. The idle though used to be like a sewing machine. Now there is this little blip but it is only seldom.

Best way I can describe it is a lean surge at idle. Will fire normally for 5-10 seconds, have a small blip, then it returns, repeat.
 
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Re: 2 wet “ish” plugs

Vanspeed said:
Been driving my ‘36 LB for almost 5 years now and I noticed a very slight miss at idle recently. I do not know the history this engine as it was given to me by a shop owner that replaced the cars entire drivetrain with new. I inspected it and had the heads off. I is sleeved on all cylinders. I just did a compression check and it is: 1-4 105/100/100/110, 5-8 100/100/100/100. Cylinders 2 and 3 look a little wet but all other plugs look like coffee and cream. Carb issue? I don’t notice coolant or oil draining down when I check them every spring. Carb is a 5 year old English 97, distributor is one of the last ones Bubba built, ignition wires and coil were all new 5 years ago. This is what the 2 and 3 plug look like.
Click to expand...
589380
 
Re: 2 wet “ish” plugs

Vanspeed said:
NGK AB-6 plugs. I put all new plugs in it. All have nice spark. Just an erratic slight stumble when it is idling. Do not notice anything at higher RPM’s. The idle though used to be like a sewing machine. Now there is this little blip but it is only seldom.

Best way I can describe it is a lean surge at idle. Will fire normally for 5-10 seconds, have a small blip, then it returns, repeat.
Click to expand...
589380
 
Re: 2 wet “ish” plugs

it's obviously not firing completely. so i would suspect inadequate spark. and i'd be lookin at the distributor cap, rotor, spark plugs, wires or condenser.
 
Re: 2 wet “ish” plugs

Condensor is new from Midwest early ford. Nothing wrong with cap, rotor, wires. Maybe I should just not worry about it as much as I am. This used to idle like a sewing machine and know it has a “spot” where it breaks up for a second. Don’t notice anything while driving it at 45-55 mph.
 
Re: 2 wet “ish” plugs

...just a suggestion.

i'm not too picky about my car, but if i had two plugs that were demonstrably wetter than the other six on an eight cylinder engine, i would want to know why.

if it appears to run smoothly at higher rpms, and stumbles at idle on occasion, i would pull the sparkplug wire off of one of the wet plugs and see if it makes a difference at higher rpms. if so, it means that that plug is probably firing correctly at higher rpms and misfiring at idle.

if so, i would run the car in a dark garage (at night maybe) and look carefully at that plug and it's sparkplug wire, and if it's like my '41 ford's sparkplug wires its inside a metal tube where a short may well be hidden and not so easy to detect.
 
Re: 2 wet “ish” plugs

Valve guide wearing and leaking oil into those two cylinders?


With new fresh plugs does it go away for a short while (and return when they get oiled up)?


Band-aid fix option is a one step hotter plug in those two to help burn off the accumulations.
 
Re: 2 wet “ish” plugs

Run it in the dark as suggested. My "guess" distributor cap. As it warms crack opens enough to cause issue.
You have good compression and I assume the oil is not milky.
Keep us posted. Chap
 
Re: 2 wet “ish” plugs

The Art Doctor said:
Valve guide wearing and leaking oil into those two cylinders?


With new fresh plugs does it go away for a short while (and return when they get oiled up)?


Band-aid fix option is a one step hotter plug in those two to help burn off the accumulations.
Click to expand...

New spark plugs showed no change.
 
Re: 2 wet “ish” plugs

chap52 said:
Run it in the dark as suggested. My "guess" distributor cap. As it warms crack opens enough to cause issue.
You have good compression and I assume the oil is not milky.
Keep us posted. Chap
Click to expand...

It idles right off the bat like this. Doesn’t need to get warm to notice it. I think I am going to pull the distributor off and have a look inside.
 
Re: 2 wet “ish” plugs

Vanspeed said:
It idles right off the bat like this. Doesn’t need to get warm to notice it. I think I am going to pull the distributor off and have a look inside.
Click to expand...

well ya...IME, poor spark usually degrades, if shorts are involved, as an engine and the engine bay warm up. so not as likely if symptoms exist on a cold start and remain relatively constant as the engine warms up.
 
Re: 2 wet “ish” plugs

Well I took the cap off and rotor and cleaned them. Used a very fine small wire wheel in my dremel to clean up the contacts and it’s idling back to normal. Perhaps those two plugs got fouled do to the contacts not being cleaned? I do have another set of heads that I want to put on this car so maybe at that time I will look a little deeper.
 
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