Spark Plug Resistance - Enough to Matter or BS?

[Lunentucker]

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[Kevin_D]

I’m not wasting time watching the video.
But unless the resistance difference was massive, like a 50% variation in the base value, it’ll make little to no difference.
Spark plugs are a high-voltage, low current device, and resistance won’t effect performance much at all.

Kevin

 

[ShadowsPapa]

Ah, another expert video.
Can't get to it for some reason - but spark plug resistance can vary from a couple hundred ohms to thousands - and that's fine and there's no real change in performance until they get way up there.
The voltages dealt with in ignition systems is high enough that "a few ohms" here and there has no impact.
Some say above 5,000 ohms is replacement time. I've seen numbers as high at 8,000 to be ok.

About 95% of all expert videos out there should be ignored.

IMO, Kevin nailed it.

The coil builds energy until the resistance of the core and the gap is overcome, then it jumps.
Too much resistance and some of the "power" of the spark is lost. But when we are talking over 20,000 volts, it takes a lot of difference to matter.

 

[Jefe1018]

That was indeed an interesting video. I’m not smart enough to understand just how much of a difference in resistance would cause a misfire code, but there could potentially be a correlation.

For those who don’t want to watch the video, the mechanic, in a professional Shop, broke down another video and applied it to the 3.6 showing an inconsistency in ohm readings amongst the factory plugs (the biggest variation coming from the spark plug that came out of the cylinder with the misfire code) and then with some aftermarket plugs.

 

[jay21mojave]

I gotta jump in.. 32 yrs with OEM Factory Field org and this was not broached.. IMO the design engineers would be a group that would interested in this in developing the ignition systems.. FWIT..From real world - Use the OEM original installed Brand of spark plugs.

 

[ShadowsPapa]

That was indeed an interesting video. I’m not smart enough to understand just how much of a difference in resistance would cause a misfire code, but there could potentially be a correlation.

For those who don’t want to watch the video, the mechanic, in a professional Shop, broke down another video and applied it to the 3.6 showing an inconsistency in ohm readings amongst the factory plugs (the biggest variation coming from the spark plug that came out of the cylinder with the misfire code) and then with some aftermarket plugs.

Limited bandwidth - videos suck that up............ could try the phone later it's got more bandwidth than our home network.

You will have a variation normally - the problem comes in when you have some at 600 ohms and another at 6,000 ohms. Something is definitely amiss then.
However, you may have a situation with 2 issues - a coil pack that is weak and high resistance caused it problems where with another coil pack that same plug would be ok. Sometimes the real problem is hidden by a lesser issue.
Any direct numbers or values?

 

[ShadowsPapa]

FWIT..From real world - Use the OEM original installed Brand of spark plugs.

That's always "safer" but hundreds, even thousands, do fine on non-OEM replacements.
Also note - FCA had serious problems with their OEM plugs - enough to issue a TSB about it. The solution was to replace the spark plugs - with the same plugs of course LOL

Then you run into situations where the resistance of non-OEM plugs is actually LOWER......... then again, we're talking tens of thousands of volts where a few hundred ohms here or there has no impact.

On a scope, you can't tell until the difference in resistance is way up there. The duration of the spark, the voltage at which the plug fires, and the taper in voltage as it fires, it's different in any way to cause one to pause and wonder. (diagnosing issues with a scope was how I got my first job after college)

 

[Jeeperjamie]

I've ran Autolite plugs in all my jeeps when they needed to be replaced and have never had a issue. I run OEM in the BMW but I let the shop do those. Not saying ones better than the other or anyone's brand is better than this. I'm sure champion spark plugs are as good as any of them. I don't pay much attention to these videos like this. Just the Autolite's are cheaper and I've never had a issue so I get those.

 

[Lunentucker]

My gut was telling me that while the plugs did vary some when tested, that the "lightning" wouldn't see the difference or care.
That's why I posted for more knowledge and input.

 

[Lunentucker]

Here's what he got on the OEM MOPAR plugs from a 3.6L
6.1, 5.6, 6.1, 5.4, 8.2, 5.2

He says the 8.2 was from the cylinder that was throwing misfire codes, but there was no discernable misfire that he could hear or see.

 

[Lunentucker]

Limited bandwidth - videos suck that up............ could try the phone later it's got more bandwidth than our home network.

You will have a variation normally - the problem comes in when you have some at 600 ohms and another at 6,000 ohms. Something is definitely amiss then.
However, you may have a situation with 2 issues - a coil pack that is weak and high resistance caused it problems where with another coil pack that same plug would be ok. Sometimes the real problem is hidden by a lesser issue.
Any direct numbers or values?

What are you using for Internet?
If you have decent cell signal I can point you towards something I used for two years during the pandemic. We had DSL that was borderline functional, but all of the additional usage from teleworking and students doing virtual all but killed it, so I scratched around and found something that was giving us unlimited data and up to 50 mpbs downloads for $58/month, after some up front hardware investments.
It's cell based but it's not a hotspot exactly.
I did have to setup an external antenna because we could only get cell service on one side of the house before that.

I did several of them for friends and neighbors and everyone has been very pleased.
One of them just got Starlink, so they were looking to sell their hardware at about 50% of what they paid.

 

[ShadowsPapa]

My gut was telling me that while the plugs did vary some when tested, that the "lightning" wouldn't see the difference or care.
That's why I posted for more knowledge and input.

Your gut usually isn't too bad, from what I've seen. Maybe it's the yeast contained within? Whatever.......
People today aren't familiar with a scope, or have any idea of how to read one. It's what I "grew up with" in a way. Lightening isn't a bad comparison....... if you look at the HEI issues of the 1980s where it blew through the distributor cap, arced along the sides of the rotor or even burned through the rotor, unless that plug offers resistance way up there, it's going to fire. Lose some energy with resistance up high in the thousands, yeah, and then add some resistance from high compression of lean mixture, you can misfire. But It's interesting, even at times amusing, to see the resistances mentioned as being problematic.

What are you using for Internet?
If you have decent cell signal I can point you towards something I used for two years during the pandemic. We had DSL that was borderline functional, but all of the additional usage from teleworking and students doing virtual all but killed it, so I scratched around and found something that was giving us unlimited data and up to 50 mpbs downloads for $58/month, after some up front hardware investments.
It's cell based but it's not a hotspot exactly.
I did have to setup an external antenna because we could only get cell service on one side of the house before that.

I did several of them for friends and neighbors and everyone has been very pleased.
One of them just got Starlink, so they were looking to sell their hardware at about 50% of what they paid.

Sounds like you were/are IT from other posts.......
We live in Polk County, Iowa. Now - that's where the armpit of the midwest is - Des Moines (adult theater marquee had that for several months years ago)
Very urban in the middle, north and west, rural in the east, southeast. It's an oxymoron.
We are ruled by monopolies in this state. Mediacom runs the cable in central Iowa and broadband cable. No one else can compete and if Mediacom can't make a trillion dollars on a plant build-out, forget it. DSL - hahaha - there's crosstalk on the lines of those who still have copper wire to the house. We're way too far from any switches for DSL and even if we were closer - meh, good luck keeping it going.
So, no cable, no DSL.
I offered to pay Mediacom part of what it would cost to build out the 3.5 miles to get to our area, knowing some of the pretty well off folks who live in the area with new homes would jump all over it. I said - 10 grand, if you come to our area. Nope, it would cost 40 grand and sorry, ain't gonna do it.
We tried hughesnet - what a joke run by a bunch of clowns. Horrible latency, strict limits on use - and the monthly allotment is broken down by xx/day so if you exceed 1/30th of your monthly in a day (such as updates to anything) they throttled you back to worse than dial-up speeds until the next day. That means an update in the AM you were done until the next day.
And I had a modem go bad - Me, responsible for over 30 remote office connections, modems of all sorts, ASAs, routers, switches and so on, I KNEW it was the modem and yet I had to pay for a formal diagnosis, then a tech HAD to come out and replace the modem. The modem was under warranty, over 100 bucks for a tech to come out and do the job. Screw that, dropped them like a rock. Besides, with our rain and snow, everyone who has dishes is complaining a lot about their TC and internet dropping in our storms. I experienced that as well.
So our only option - cellular data.
Well - if you look at the cell coverage maps of this part of the county, then lay the county properly maps over top of that you'll see something amazing - cell coverage ends right at our property lines on all sides. I showed the cell people that - one lady was at a total loss for words. I asked - so do you guys have something against us that you don't cover 3.5 pie shaped acres? She called a guy over to look at the maps, she couldn't believe it.
We're in a low area, between hills and a lot of trees. PEople who believe Iowa is flat have never REALLY been here or off the interstates.
So, there we are - only one company covers rural areas well at all, only one company gets normal cell phone coverage out here. And only one company has data that works out here. Towers aren't that far away, really, but may as well be 40 miles away due to the hills and trees.
So we're on cell.
It's now unlimited for the phones (certain conditions apply, of course) but there's limits on the "home data networks". 50 gig. And it's not lightening fast.
Oh, and guess where Skylink does not cover? Yeah, our part of the state!
(it so closely resembles something else I can think of, I keep seeing a terminator appearing in our yard if I could go that route)
No DSL possible.
No cable possible
Dish sucks, been there, dumped that.
Cell data is all we can get - not stellar but for web use it works. Just that Youtube and other videos you need to be watchful of. Last month I hit our limit on the last day of the billing cycle.

EDIT - nearly missed your last paragraph... We have an Orbi inside and it's "OK" We burned through 3 of their other routers in 4 years and they had to be hard-reset every few weeks due to troubles. Crap home cell routers. There's a big story with those routers, too........ crap reception. Our only choice is a pro-installed outside antenna but most are directional and some days the one by Runnels is our best bet, the next week the one by Carlisle is better, then later one I can't figure out north of us is better but I can never find a tower north of us! So it must be invisible!
I'm ready to bring in a pro to set something up....... but US Cellular doesn't offer much in the line of equipment and no other company has their coverage (only USCC customers can use phones out here!)

 

[Lunentucker]

Your gut usually isn't too bad, from what I've seen. Maybe it's the yeast contained within? Whatever.......
People today aren't familiar with a scope, or have any idea of how to read one. It's what I "grew up with" in a way. Lightening isn't a bad comparison....... if you look at the HEI issues of the 1980s where it blew through the distributor cap, arced along the sides of the rotor or even burned through the rotor, unless that plug offers resistance way up there, it's going to fire. Lose some energy with resistance up high in the thousands, yeah, and then add some resistance from high compression of lean mixture, you can misfire. But It's interesting, even at times amusing, to see the resistances mentioned as being problematic.


Sounds like you were/are IT from other posts.......
We live in Polk County, Iowa. Now - that's where the armpit of the midwest is - Des Moines (adult theater marquee had that for several months years ago)
Very urban in the middle, north and west, rural in the east, southeast. It's an oxymoron.
We are ruled by monopolies in this state. Mediacom runs the cable in central Iowa and broadband cable. No one else can compete and if Mediacom can't make a trillion dollars on a plant build-out, forget it. DSL - hahaha - there's crosstalk on the lines of those who still have copper wire to the house. We're way too far from any switches for DSL and even if we were closer - meh, good luck keeping it going.
So, no cable, no DSL.
I offered to pay Mediacom part of what it would cost to build out the 3.5 miles to get to our area, knowing some of the pretty well off folks who live in the area with new homes would jump all over it. I said - 10 grand, if you come to our area. Nope, it would cost 40 grand and sorry, ain't gonna do it.
We tried hughesnet - what a joke run by a bunch of clowns. Horrible latency, strict limits on use - and the monthly allotment is broken down by xx/day so if you exceed 1/30th of your monthly in a day (such as updates to anything) they throttled you back to worse than dial-up speeds until the next day. That means an update in the AM you were done until the next day.
And I had a modem go bad - Me, responsible for over 30 remote office connections, modems of all sorts, ASAs, routers, switches and so on, I KNEW it was the modem and yet I had to pay for a formal diagnosis, then a tech HAD to come out and replace the modem. The modem was under warranty, over 100 bucks for a tech to come out and do the job. Screw that, dropped them like a rock. Besides, with our rain and snow, everyone who has dishes is complaining a lot about their TC and internet dropping in our storms. I experienced that as well.
So our only option - cellular data.
Well - if you look at the cell coverage maps of this part of the county, then lay the county properly maps over top of that you'll see something amazing - cell coverage ends right at our property lines on all sides. I showed the cell people that - one lady was at a total loss for words. I asked - so do you guys have something against us that you don't cover 3.5 pie shaped acres? She called a guy over to look at the maps, she couldn't believe it.
We're in a low area, between hills and a lot of trees. PEople who believe Iowa is flat have never REALLY been here or off the interstates.
So, there we are - only one company covers rural areas well at all, only one company gets normal cell phone coverage out here. And only one company has data that works out here. Towers aren't that far away, really, but may as well be 40 miles away due to the hills and trees.
So we're on cell.
It's now unlimited for the phones (certain conditions apply, of course) but there's limits on the "home data networks". 50 gig. And it's not lightening fast.
Oh, and guess where Skylink does not cover? Yeah, our part of the state!
(it so closely resembles something else I can think of, I keep seeing a terminator appearing in our yard if I could go that route)
No DSL possible.
No cable possible
Dish sucks, been there, dumped that.
Cell data is all we can get - not stellar but for web use it works. Just that Youtube and other videos you need to be watchful of. Last month I hit our limit on the last day of the billing cycle.

EDIT - nearly missed your last paragraph... We have an Orbi inside and it's "OK" We burned through 3 of their other routers in 4 years and they had to be hard-reset every few weeks due to troubles. Crap home cell routers. There's a big story with those routers, too........ crap reception. Our only choice is a pro-installed outside antenna but most are directional and some days the one by Runnels is our best bet, the next week the one by Carlisle is better, then later one I can't figure out north of us is better but I can never find a tower north of us! So it must be invisible!
I'm ready to bring in a pro to set something up....... but US Cellular doesn't offer much in the line of equipment and no other company has their coverage (only USCC customers can use phones out here!)

If you have one twinkling bar in your house or outside this setup will work.
That said, I would steer you to Starlink and choose the RV plan, which ships immediately.
Once you get that you can dump DBS TV and stream everything for about 50% of what you've been paying. We use Rokus and Fubo TV.
We were going to go to Starlink, but the miracle of rural fiber showed up, so I cancelled that.
Starlink - $500 up front and $130/month - 150 mpbs is pretty average. That's the RV version, which ships immediately.

The cell setup that I was on before fiber - $300 up front and $58/month.
There are no data caps on either.
Our nearest tower was 4.5 miles and with topographical barriers.
It's a Mofi LTE router + a Prepaid unlimited data plan with a sim card that's registered as a phone through an old grandfathered corporate plan.
I used a Proxicast directional antenna outside of the upstairs utility room window pointed at the tower.

Like I said, cell signal on the phone was weak, but that antenna pulled it in.

 

[ShadowsPapa]

If you have one twinkling bar in your house or outside this setup will work.
That said, I would steer you to Starlink and choose the RV plan, which ships immediately.
Once you get that you can dump DBS TV and stream everything for about 50% of what you've been paying. We use Rokus and Fubo TV.
We were going to go to Starlink, but the miracle of rural fiber showed up, so I cancelled that.
Starlink - $500 up front and $130/month - 150 mpbs is pretty average. That's the RV version, which ships immediately.

The cell setup that I was on before fiber - $300 up front and $58/month.
There are no data caps on either.
Our nearest tower was 4.5 miles and with topographical barriers.
It's a Mofi LTE router + a Prepaid unlimited data plan with a sim card that's registered as a phone through an old grandfathered corporate plan.
I used a Proxicast directional antenna outside of the upstairs utility room window pointed at the tower.

Like I said, cell signal on the phone was weak, but that antenna pulled it in.

Interesting........
Cell calls work fine these days. It was a bit iffy years ago, and I put up a 3G repeater many years ago which helped, but then more towers were built and now calls work fine. Other people with other phones and companies - not so much. Data is better than it was but my wife still complains "how come this isn't going through, it says internet connectivity problems" and she instantly thinks I can fix it by doing something with our router. I can't get across that phones go direct to the towers - nothing, zip, to do with anything and ya just have to wait. Calls - fine, data, not so much.
I had to make sure, and in fact every night I'd check her phone to make sure wifi was OFF or she'd kill our bandwidth in a week. then we got unlimited data on the phones. But data connections not totally reliable.
The Orbi router is the best one we've ever had. Up time is fantastic. I may have to reboot it once or twice a year at most. But sometimes a simple YT video will "pause".

So how can Starlink RV work here if there's zip for coverage in our area?
How could it work if there's no coverage for home even close to us?
Of course NY where there's a ton of money and bazillion towers and broadband all over creation is well covered - Iowa, even Chicago? No.
Don't you need to be able to contact a satellite? We're not far from Chicago - SE of Chicago, coverage is hours west of us, likely out of satellite view.

$225/month for two phones, a tablet and our home internet. Phones are paid for so that's not part of the cost.

 

[Lunentucker]

What's the source of this map and what do the two colors represent?
You appear to be in the same shading that we are and lots of people here are on Starlink now.

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