If you get AcDelco thru a third party on Amazon you run that risk. If you get AcDelco thru Amazon (sold by, stocked by, and shipped by Amazon) themselves, you will be fine. You have to read carefully where it’s coming from or selling by. AcDelco did a deal with Amazon over a decade ago. I buy 100’s of acdelco parts per year thru Amazon. I have no local acdelco dealer.

SB,

Yup. But, at over $8 difference, EACH (I am planning to install all new if I have to change any), I doubt RockAuto is going to charge $65+ for shipping. At least I HOPE not. We'll see.

Thanks. Brad.
(937)545-8991

I work on lots of chevies. I only change coils that are needed. Some last ‘forever.’

Broken record….skip….skip….skip
#1 coil killer is big plug gaps . Same with most all other ignition parts….modules/caps/rotors/wires/coils….if so equipped.

Guys,

Next "what if".....

In the event it's not the coil pack(s), I have to look at the injectors. I've already spoken with Smitty, and have cleaning them worked out. But I'm thinking about what has been said about the CoolFuel module. I've looked it up, and I know what it looks like, but I can't seem to find it. Whereabouts is it located on these 496s?

Thanks. Brad.
(937)545-8991

Guys,

Just swapped plugs. These were run one afternoon, including one extended WOT run of about ten minutes, which was still well under reasonably expectable max RPM. Still no throttle dump; just idled onto the trailer, as previously explained. Also have not test run with coil packs swapped yet. Probably do that Wednesday, but wanted new plugs and wires for the test.


https://cimg3.ibsrv.net/gimg/www.off...f1b9d9e90.jpeg
https://cimg4.ibsrv.net/gimg/www.off...024ae30cb.jpeg
https://cimg5.ibsrv.net/gimg/www.off...a4855b087.jpeg
https://cimg6.ibsrv.net/gimg/www.off...0d37cc894.jpeg

Compare these to the last set of plugs (pictures above).

The plugs that were wet and fouled previously (cylinders 4 & 7) are now spotless, as if never having seen combustion. 🤔

I know what I’m thinking, but I don’t really know what I’m doing. I want the experts’ opinions.

Thanks. Bead
(937)545-8991

You engine shouldn't have the probmatic gen 3 cool fuel setup with the paint issues. Just the filter, 2 pumps and fuel cooler. There could still be issues with the injectors though.

Looks like you missed all of SB's advice on plug gap? 😉

4 and 7 don't smell like gas? Looks like they never had spark?

What's up with plug 5 electrode?

It's hard to see your pictures up close. Are there any signs of small black or silver spots on the porcelain of any of the plugs?

This is a 5% off code for Rock Auto if you (or anyone) needs its. It's good till Sept 20, 2022.
00DCE38C03F1C8

Underpsi,

Good to know on the CoolFuel module.

Injectors will be next on the docket if the coil packs don’t solve the issue. It was one or the other first. Coil packs won the coin toss.

These plugs went in prior to this conversation. They are all factory gapped, and appear to all be ~.060”. The plugs that just went in are gapped at .040”. I’m listening. 😊

No gas smell to speak of. The boat has been sitting for a week and a bit since it was ran last. Not sure if that would allow the gas to evaporate or not. I agree on the appearance of no spark.

Not sure what’s up with #5. Looks to be some hazing. Nothing scrapes off when I hit it with my burr knife.


https://cimg4.ibsrv.net/gimg/www.off...bcae34de0.jpeg

No specks or any kind that I can see. The porcelains all look pretty clean. Even through my magnifying visors. The bases of the threads all look pretty heavy in soot. Probably from the extended run at WOT, but still short of expectable RPM (I’d guess).

Thanks for the discount code. I’ll definitely capitalize on that if I need to place an order.

Thanks. Brad.
(937)545-8991

That plug looks like something hit it? Aluminum?

Take a picture of the side of the ground strap on the plugs, like this. Trying to see the heat line, if there is even one.
https://cimg4.ibsrv.net/gimg/www.off...d61f979354.jpg

Just be sure to enter it in the correct place - it's a little confusing on RockAuto. That code goes in the box marked "how did you hear about us", not a coupon code or discount code box.

Lisle (or other’s) spark testers are under $20 and found literally everywhere, including your local parts store:


https://cimg5.ibsrv.net/gimg/www.off...ec264eb0a.jpeg