Pinging at WOT

[duffman04]

Having what I would describe as "pinging" at WOT even in the cold weather. Car is a 100% stock '94. Just curious where people think I should start. I figured i'd start with changing the plugs since its probably been 10000km's or so since they were changed. Aside from the symptoms at WOT the car drives great and really hasn't had any issues at all.

Also, here it is on a nice 70 degree January drive up to the "mountains" of Arkansas. The gravel road wasn't exactly a plan...
IMG_0914.jpg

I don't know why the picture is upside down either haha

Edit: car has K&N filters, so 99% stock.

[gage]

when you change the plugs take photo documentation making sure to label each plug as it comes out. You need to identify which cylinder is pinging so you can do further diagnostics and determine if you need to pull a head

[uvbnbit]

bad gas?

[duffman04]

I first noticed it on my last tank of gas so that might be all it is. On saturday I filled up from a half tank (always 93) and I still heard it. If it is bad gas it must still be in there enough to cause the problems. On my turbo'd cars I've thrown a gallon of e85 in the tank to see if its knock related, I am a little more hesitant with the viper since its seals are old and likely not at all designed for much more ethanol.

Also, I pull a couple spark plugs and they look completely fine. I'll pull the rest in a couple days when my new ones get here. Went with Champion RC12ECC.

[Martyb]

Read the plugs once you pull them, and through in a can of octane booster until you burn through that fuel, just to be safe. If your detonating you should see it on the plugs.

[bluesrt]

poopy crappy stale fuel, it goes to hell fast

[toote]

Over here the 93 can have lower octane than 91 due to that it sits longer periods since the usage is so much lower of the 93.

So if you don't actually need the 93 the 91 might be a safer choice.

[duffman04]

OK. So don't make fun of me too much but the plugs were terrible... I was assuming that the plugs would have been changed when the head gaskets were swapped about 10yrs/10000km's ago but I honestly think these are the original '94 59000km spark plugs. The plug insulators were speckled with crap as you can see in the photo and the gaps ranged between 0.040-0.045. Left of photo represents the front of the motor with its corresponding plug locations.
IMG_0915.jpg

Took the car for a drive and not a single ping in the 15-20 mile trip with a few WOT mixed in. Replaced plugs with Champion RC12ECC gapped at 0.032

Any recommendations for a fuel system cleaner that actually does anything?

[uvbnbit]

I think there was a thread few years ago (most likely on other site) regarding this. Lot of technical jargon lol.
bottom line, get the good stuff i.e. not the .99 "fuel system cleaner"
maybe Tom F&L GoR will reply.

[qc-teky]

OK. So don't make fun of me too much but the plugs were terrible... I was assuming that the plugs would have been changed when the head gaskets were swapped about 10yrs/10000km's ago but I honestly think these are the original '94 59000km spark plugs. The plug insulators were speckled with crap as you can see in the photo and the gaps ranged between 0.040-0.045. Left of photo represents the front of the motor with its corresponding plug locations.
IMG_0915.jpg

Took the car for a drive and not a single ping in the 15-20 mile trip with a few WOT mixed in. Replaced plugs with Champion RC12ECC gapped at 0.032

Any recommendations for a fuel system cleaner that actually does anything?

The only ones that I've used that see to do anything at all are Seafoam and Techtron - I was mixing stronger than recomended though. Noticed it mostly on my old Honda Valkyrie M/C. It's a 6 cylinder with 6 carbs that have very small primaries. Both of those would open them back up if they got clogged. Have used them both on my newer injected vehicles, but I can't really tell if it did any good - didn't seem to hurt anything.

[Martyb]

I believe Techron is as good as it gets off the store shelves.

[duffman04]

Thanks guys! I actually did find the old thread from the other site where Tom F&L GoR commented on the subject. We're going to be driving the car a bunch this weekend so I'll run a bottle of Techron concentrate plus Complete fuel system cleaner through it for good measure. I am amazed at the positive reviews on the stuff.

[daveg]

Techron is the stuff to use IMO....