so me and a buddy replaced my plugs tonight they were pretty bad. i had the stock ac delco ones still in at 65k. so i told him to get me wires and plugs from his shop he got ngktr5IX iridium plugs we gapped them at 040 everything seemed to go together just fine. after the bitch it was to get the old ones off. first start up seemed great seemed to idle much better. then half way to my gf's house it started to sputters and shudders at idle and cruising, it still is currently doing it me and my buddy are going to take a look at them tomorrow any idea whats wrong? are the sparks to cold for my set up? or is the gap wrong? idk

my current set up is just magnaflow catback and slp lid, i have ARH's going on sometime in may

 

i would recheck the plug wires one mite not had been snaped on all the way.

 

Check to make sure all wires are still snapped in and plugs all tight

 

^^^ good timing lol

 

Will bet it is the wires.
Also could be a broken plug (hope you didn't over tighten).

 

i run the same plug with msd 8.5mm wires and had 0 issues during my header install. i think i gapped mine at .50 though...cant remember. just check ur plug wires to see if they are on all the way, and check the plugs for cracks like mentioned earlier.

 

2 clicks, if you don't hear 2 at the coil and one on the plug the wire is not all the way on.

 

I was under the impression that you don't mess with the gap on the iridium plugs and that they should all come at .040 for the LSx's. Or if you really feel like it you have to be extra careful not to damage the tip of the electrode... and no sliding tools (like gap checkers) into the gap. For the most part the manufactures seem to only recommend gapping to smaller if you absolutely have to but don't want people to try to open up the gap. If you absolutely have to open them up, using needle nose along the side of the ground electrode will probably be ok, but not inserting something and prying them open.

Double check the wires. Sometimes they don't like to snap in all the way. Pretty much everyone else has already said this but I am reiterating it.

 

all of the gaps on my iridium plus were all off....everywhere fomr like .030-.050 i always check the gap on any plug... i had to fix all of em...

 

i run my tr55ix iridiums at .058... thats how they came pregapped.

 

Hi Guys

The plugs and wires recommended by NGK for the
2002 CHEVROLET CAMARO Z28 / V8 / 5.7

TR5GP (G-Power) platinum
TR5IX (Iridium IX version)
IZTR5B-11 (Laser Iridium series)

They all come pre-gapped at 0.040" or 1.1mm, basically the "-11" on the NGK part number stands for the gap setting 1.1 mm

I have noticed some of you are using TR55IX instead of TR5IX
TR5IX is Iridium IX Plug, 14mm Thread Size, 17.55mm (.691") Reach, 5/8" (16mm) Hex Size, Tapered Seat, Resistor, Solid Terminal Nut, Projected Tip, Fine Wire (0.6mm) Iridium Center Electrode, Tapered Cut Ground Electrode, .040" (1.02mm) Gap, Heat Range 5

TR55IX is Iridium IX Plug, 14mm Thread Size, 17.55mm (.691") Reach, 5/8" (16mm) Hex Size, Tapered Seat, Resistor, Solid Terminal Nut, Projected Tip, Fine Wire (0.6mm) Iridium Center Electrode, Tapered Cut Ground Electrode, .060" (1.52mm) Gap, Heat Range 5

The TR55IX has a larger pre-gapped setting.

As for the wires they have the NGK-RC-GMX090 "blue wires", these are their performance wire sets.

As for re-gapping Iridium plugs, NGK does not recommend it but that does not mean you cannot. However, you should NOT use the "coin" style gapping tools, you can easily break the fine tip iridium tip and then you can have issue with performance.

In your engine is modified, you can then go with a one or two step colder plug. In that case, it would be the TR6IX (one step colder). NGK has higher numbers for colder plugs, for the complete NGK symbol description, just simply visit their site at:
http://www.ngksparkplugs.ca/documents/partnumberkey.pdf

Hope this helps.

Thank you.
Frank Vessella

 

Frank you nailed it right on the head.

TR5IX is correct for this application and shouldn't be giving you any issues. As others have mentioned first check the wires, it sounds like one may not be pushed down all the way. If the issue still persists then remove the plugs and check for any cracks in the ceramic and also check that all the gaps are correct. They should be between .036-.039." new out of the box (.9-1.0mm) with the TR5IX.

For applications where the gap needs to be changed from stock it isn't a problem to do so as long as they are gapped correctly which is not to put any pressure on the fine wire center electrode. Only the ground electrode (J-piece) should be moved.

 

I thought tr55ix is the correct plug? It has the .060 gap that these engines call for...why would you want to run .039 gap on a basically stock/bolt on ls1?

 

Around 2003 GM issued a tech bulletin recommending a gap change from .060" down to .040" due to a change from platinum to iridium OES plugs and it affected all prior year vehicles as well.

That's why when you look up plugs for your application all the plug manufacturers now recommend .040" instead of the original .060" that's in the owner's manual.

However, the issue was the plugs themselves and not the ignition system or any other related problems so if you want you could still run the TR55 series and run the stock .060" gap if you prefer. However according to GM there should be no loss in performance if you do run the smaller .040" gap.

 

Very smart guy here.

Even I ask him plug questions from time to time.

 

I knew there is no performance loss, my concern would be a loss in fuel mileage... Don't you want to run the widest gap possible without spark blow out for maximum efficiency and mileage?

 

If your wires are old sometimes handling them while changing plugs will break them on the inside while they appear just fine...

Edit: Yeah king missed it....

 

If Im not mistaken the op said he changed wires in his first post.

 

That's a good question and according to GM there should be no issue with the change. I really can only tell you in the four years I did tech support for NGK I never had a report from a customer of a loss in mileage. My guess is that it would be very minimal....maybe a percent or two at worst.

 

Hi Brandon

Please correct me if I am wrong, but over the years I have seen so many people ignore the O2 Sensors. Some folks will run on the same O2 Sensors for the entire life of the vehicle, however the same people will change their plugs and wire set on a regular interval because they are so concerned on loss in fuel mileage. They will wait until they get a "check engine" before they change them.

The reality is an old O2 Sensor will actually give you a greater loss in fuel mileage then compared to an older plug or wire set.

The problem is when a plug or a wire set gets old, you will actually feel the poor performance with the vehicle, but when an O2 Sensor get old but does not trigger the "check engine" it is basically eating up the loss in fuel mileage.

JMHO

Again, please correct me if I am wrong.