Just put in some Autolite 106 plugs and call it a day! They are a copper core plug so you should get less resistance, but you will need to change them once a year.

I've used NGK plugs in the past and never had anything but issues with them. The autolite 106 plugs have worked GREAT with N20 and NA. Never had a single issue with them.

 

I normally run Autolite plugs in everything. Maybe I'll just do that. Although I really don't want to change all the plugs right now. I might just replace the drivers side plugs AGIAN and deal with this in the summer when it acts up agian.

Are NGK TR55 and TR% plugs resistor???

 

I'm using Autolite double-platinums in my AFR heads with the Delteq.
The plugs had about 30K miles on them before I installed the Delteq.
I only have about 2K miles on them with the Delteq -- no problems.

If you decide to look into the problem, here is my suggestion:
Take each spark plug wire off and measure the resistance from end-to-end with a good ohmmeter -- by no means should they read infinity.
I made my own wires for my Delteq from "roll-your-own" Accell wires, using the correct spark plug terminal crimper.
One thing I learned years ago was to always check each spark plug wire with an ohmmeter before installing it. It doesn't matter who made them, someone else or me; I've seen too many wires that weren't terminated correctly and you couldn't tell by looking at them.

If you don't find any problem with the wires, try non-resistor plugs.

Tom Piper

 

Just some plug trivia...

You can measure the resistance on NGK & Bosch plugs if you have a DMM with sharp probes. It should read 5k +-a few k. There is a fairly wide tolerance on them. The resistor is fired-in. It is like a ceramic slurry and takes a LOT of heat to put it in there, so I doubt engine heat could kill it.

Champion plugs have a pellet resistor and you CANNOT measure them with an Ohm meter unless you have one with a thousand volt potential. I don't know about resistor construction of the Autolites & other American brands - something I should look into. Most plugs do have the copper center conductor.

 

Yes the TR5's and TR55's whether common or iridium are resistor type.

Hey I was reading some more regarding the "waste spark" ignition and found this from the GM 94 shop manual.

"It is posssible for one spark plug to fire even though a plug wire from the same coil may be disconnected form its "companion" plug. The disconnected plug wire acts as one plate of a capacitor, the engine being the other plate. The two "capacitor plates" are charged as a spark jumps across the gap of the connected spark plug. The "plates" are then discharged as the secondary energy is dissipated in an oscillating current across the gap of the still-connected spark plug. Secondary voltage requirements are very high with an "open" spark plug or wire. The ignition coil has enough reserve energy to fire the still-connected plug at idle, but possibly not under high engine load. A more noticable misfire may be evident under load; both spark plugs may then be misfiring.

Uh huh. The last part sounds like what you experience.

The other thing I noticed with regard to this "waste spark" system was what the manual said regarding testing. "When checking for spark the "companion" plug wire should be properly grounded to create a good spark" (they mean on the other plug obviously). But here's the good part, "and to avoid overstressing the coil". Could this be interpreted to mean that bad plugs or wires could kill coils????? Interesting since we see more dead coils on this system than any other.

And since you have to ground properly to not stress the coil. Could that mean that a non-resistor type plug is better since it gives a better path to ground . I couldn't find a specific requirement in the book but of course the recommended plug from GM is a resistor type.

Just FYI. Seems that what you gain by getting rid of the opti portion with a Delteq, you loose with the apparent weakness of "waste spark" ignition system. However, it sure is easier to replace the coil/ICM on a waste spark system compared to replacing optis or opti caps and rotors.

 

My suggestion is about the resistors heating up has to do with the heat generated internally in the resistance from the Nortstar coil current -- not engine heat.
Since the resistor is inside the ceramic part of the plug, it does not have a very good way to dissipate heat. NorthStar coils are potent and supply a lot of current.

That tells me there is actually a small gap inside the ceramic part of the plug that the spark has to jump, as well as the spark plug gap. That's the same trick that non-fouling spark plugs use.

Tom Piper

 

More than a Crane Hi6 & LX92 coil? That coil secondary has wire in it the size of a hair and doesn't pass enough current to burn up a big plug resistor. The plug wires would shrivel up before that resistor would ever fizz out. I don't think that's what's happening, but you could always measure them & find out. If someone wants to send me the plugs, I can measure them or send them to NGK and have the engineers there look at them for you.
Tom, in Champion plugs, there is a spring in there to connect the resistor to the SAE elctrode. You just can't measure it with a normal Ohm meter because there is some film on the parts that the 9v battery cannot overcome, but when there is 20kv on there, it isn't so insulated. It's also hard to explain, but it changes resistance when it actually in the engine, all heated up & working. If you ever get curious, you can unscrew the top off a Champion plug and shake out the little parts. An NGK has to be cracked open or cut in half with a diamond saw if you want to look at the fired-in suppressor.

 

Just a thought I had. Have you contacted Delteq about this problem? Possibly they would recommend a plug suited for their system.

 

NGK TR55s were sugested for an unboosted LT1 when I bought the Delteq

 

I dont think the plugs are your problem there are too many people on here with delteqs and no complaints

im not one of them
i assume you bought you delteq from elitesparkplugs.com
do some research on them and their spark wires

i got rid of mine
ill see if that fixes it soon