[BigCee]

Just ordered NGK spark plugs and Denso coils, so I'm hoping for the best
Like one or two of you, I experience a slight stumble at low idle in gear. Sometimes its very slight and not consistent.

 

[AeroZ]

Just ordered NGK spark plugs and Denso coils, so I'm hoping for the best
Like one or two of you, I experience a slight stumble at low idle in gear. Sometimes its very slight and not consistent.

Let un know if new plugs and coils fixes it.

 

[MCSETots]

Thanks for the info y’all.



There is another one of those “lifetime of the vehicle” comments. 🤣

To answer the question of why I would change a perfectly working part, here is my reasoning. It is working properly now, but for how long? I do not want to be halfway through a Yellowstone vacation when they start to go out. The repair could be done on the side of the road or in a parking lot, if allowed. Now going by my logic above I should really buy a brand new vehicle but that is out of the question. I just thought that since I was already in there that I might as well change them.

"It is working properly now, but for how long?"

Sadly, since we're in the world of Chrysler products, that's pretty logical thinking. Unfortunately, Chrysler didn't make the 62TE transmission field replaceable, or I would have carried an extra on my vacation - but that's a whole other story.

Regarding your coil packs and spark plugs, you may find that many, many Chrysler owners have gotten in excess of 150k miles from both. Generally, having to replace them earlier than that is a result codes be thrown for misfires and such. Don't know if you've done an OBD-II scan for look for issues, but I'd recommend starting there before putting out a few hundred dollars for possibly unnecessary repairs. On a side note, the 3.6 engines are notorious for other issues that can look like a spark plug or coil pack failure, such rocker arm/bearing failure, wiring harness & connector issues.

Good luck!!!

 

[Jeepman]

The Jeep's engine was running rough this morning, must be the NGK spark plugs that's causing the problem. What else could it be?

On second thought it may be the throttle position sensor that throws a P0123 code every so often. I have a new one but may have to destruct the old one to loosen up the two small diameter bolts. They don't want to break loose, no how. I can't get a good grip on them with vice grips either.

Yes, many problems are blamed on spark plugs while other components may be causing the problem. There's not much rocket science to spark plugs, other components may be more complicated.

Watch out for NGK clones and their two types of Iridium spark plugs, one performing quite different than the other. I suppose other brands are cloned as well. It's sort of scary to buy ignition parts and sensors online.

 

[Turbo84]

At least on TJ the sensor ground for TPS also goes thru clockspring and since harness inside clockspring moves it can develop intermittent TPS problems so just unpluging clockspring and testing how it runs can be a useful diagnostic test

don’t need to unplug the airbag clockspring connector just the non yellow one and beware with clockspring unplugged you loose use of horn

 

[Sienile]

What??? It makes no sense to have any sensor grounded through the clockspring.

 

[Turbo84]

Yes it does as cruise mux ground uses same sensor ground circuit K4 as throttle position sensor
And to get to cruise switches has to pass thru clock spring

 

[Sienile]

But it should be grounded on the body and just that branch going to the cruise.

 

[Turbo84]

A sensor ground is a pcm connection other than a straight ground and more the a few TJ owners with intermittent TPS codes and running problems found it went away when clock spring unplugged
Why do you think they don’t just ground the sensor ground and ground the pcm
Same reason obd2 connector in pci era has 2 seperate ground circuits pin 4 and pin 5
If a sensor ground could function just as well with just a body/battery ground ther would be no need for all the extra wiring

 

[Turbo84]

Sensors, if they have the ground isolated from the sensor body (for example TPS, pressure, temperature sensors), they must be grounded to the sensor ground on the ECU, not the engine ground. The reason for this is as given in the second example above; if you ground the sensor to the engine ground, then its output is going to be offset by the ground current times the ground resistance. This is why ECUs have dedicated sensor ground wires.

fromhttps://www.hpacademy.com/forum/general-tuning-discussion/show/sensor-ground-chassis-ground-question

 

[Turbo84]

Try this thread for an example
I was Digger84 over there

Replaced TPS stil have problems,

99 TJ 4.0 Threw a p0123 code. I replaced the tps with a Mopar tps...not an off brand. Still had issues. Checked for vacuum leaks couldn't find any. Removed the throttle body and cleaned everything. Still had issues. Replaced the IAC and still have a problem. Engine runs fine if I remove...

www.wranglerforum.com

 

[Special Edy]

The Jeep's engine was running rough this morning, must be the NGK spark plugs that's causing the problem. What else could it be?

On second thought it may be the throttle position sensor that throws a P0123 code every so often. I have a new one but may have to destruct the old one to loosen up the two small diameter bolts. They don't want to break loose, no how. I can't get a good grip on them with vice grips either.

Yes, many problems are blamed on spark plugs while other components may be causing the problem. There's not much rocket science to spark plugs, other components may be more complicated.

Watch out for NGK clones and their two types of Iridium spark plugs, one performing quite different than the other. I suppose other brands are cloned as well. It's sort of scary to buy ignition parts and sensors online.

Spark plugs are so often the issue. But, they're also extremely easy to visually inspect for worn electrodes or cracked ceramic.

TPS, same thing. Usually they are 3 wire, just a simple potentiometer. You can measure the resistance to make sure that it is linear and without deadspots. The resistance from positive to negative should be a set value. If the signal wire to either ground or positive checks out as being linear resistance, and the negative to positive resistance is the correct value, the sensor should be good.

Coils can be tested too. Primary and Secondary resistance.

 

[Turbo84]

some interesting info here

ECU Grounding - the DOs and DONTs - Haltech

across a debate about the best way to ground your ECU. So today we are going to get our nerd on and look at the theory of electronic circuits and help you figure out the optimal grounding solution for your particular wiring application.

www.haltech.com

 

[jm70]

I spent 30 years in dealer parts departments. 25 with MOPAR. I guarantee 90% of the coils I sold were not needed. They would buy it and then come back and want to return it and buy another guess.

 

[Dean407]

I got NKG plugs and coil packs I put in around 100k too. No issues.

 

[Jeepman]

I got NKG plugs and coil packs I put in around 100k too. No issues.

Out of warranty yet?

I spent 30 years in dealer parts departments. 25 with MOPAR. I guarantee 90% of the coils I sold were not needed. They would buy it and then come back and want to return it and buy another guess.

I hear you. "He who has ears to hear, let him hear". I learned that in Sunday School, pretty basic. But sometimes my head is a bit thick though.

 

[williamgilles2014]

Hey guys called lordco just now got some John hamm sounding guy.

He quoted me ngk said they don't have champion

Ngk grower up to 80k he said, $10/plug

Then said those are garbage bottom of the line plugs , I should go with ":laser plugs "

I asked wtf ? He said ngk high density laser iridium last for 160k and are $23 each . Then went on to say they cost more because they're the best . Price equals better etc .

I think I'm getting the classic upsell amd I'll have to see what rock auto has to say about that.

He also said some nonsense about q ground strap and I said, what? These are spark plugs they're grounded on the motor body .

Any thoughts ?

 

[Sienile]

The NGK Lasers wear out nearly as fast as regular NGKs. Not worth the extra. NGK is the best brand.

The electrode tang is also called a ground strap. Just confusing terminology.

 

[williamgilles2014]

The NGK Lasers wear out nearly as fast as regular NGKs. Not worth the extra. NGK is the best brand.

The electrode tang is also called a ground strap. Just confusing terminology.

Thank you sir. All my vehicles have run ngk since the 90s , domestic and foreign. Although in Canada it's all foreign brands technically

 

[Westphal]

Hey guys called lordco just now got some John hamm sounding guy.

He quoted me ngk said they don't have champion

Ngk grower up to 80k he said, $10/plug

Then said those are garbage bottom of the line plugs , I should go with ":laser plugs "

I asked wtf ? He said ngk high density laser iridium last for 160k and are $23 each . Then went on to say they cost more because they're the best . Price equals better etc .

I think I'm getting the classic upsell amd I'll have to see what rock auto has to say about that.

He also said some nonsense about q ground strap and I said, what? These are spark plugs they're grounded on the motor body .

Any thoughts ?

They're better cause he'll make more money on the "laser" plugs. Double platinum is fine.