Perplexed - Fouled plugs + three melted/missing tip ends....
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Perplexed - Fouled plugs + three melted/missing tip ends.... I've been breaking in my new turbo motor and have about 500 miles on it. I'm running pig-rich, to the extent that I have a little black smoke when I nail it. The goal was to start really rich, and tune my way back after getting HP Tuners. I just got Hptuners, but was having problems with flooding and cold starts.
I have loaded a bit leaner tune using Hptuners, but still couldn't get the car to start after sitting in the cold for 5 days. So, I went and got some new NGK TR6 plugs, and pulled the existing plugs.
They're all pretty fouled, but the surprising thing is that the very tip of the ends over the diode on 3 of them are missing. I had thought that this was usually caused by lean conditions and detonation. There is virtually no chance I leaned out or detonated. I'm only running at 5 psi while breaking the engine in, used a scanner after break-in and was running WOT with not a lick of ping, and have been running 92 octane gas with octane booster.
Is it possible to wet foul plugs, then burn them up when loads augmented by boost and ignition finally starts to clear the fouling? Going from a really cold plug condition to a really hot one, etc? ... This has got me a bit worried. I'll root around a little in the plug holes with a telescoping magnet to see if there is anything in there before putting the new plugs in.
I'm worried about those tips. They don't just evaporate, and had to go somewhere. Anyone seen anything like this?
I have loaded a bit leaner tune using Hptuners, but still couldn't get the car to start after sitting in the cold for 5 days. So, I went and got some new NGK TR6 plugs, and pulled the existing plugs.
They're all pretty fouled, but the surprising thing is that the very tip of the ends over the diode on 3 of them are missing. I had thought that this was usually caused by lean conditions and detonation. There is virtually no chance I leaned out or detonated. I'm only running at 5 psi while breaking the engine in, used a scanner after break-in and was running WOT with not a lick of ping, and have been running 92 octane gas with octane booster.
Is it possible to wet foul plugs, then burn them up when loads augmented by boost and ignition finally starts to clear the fouling? Going from a really cold plug condition to a really hot one, etc? ... This has got me a bit worried. I'll root around a little in the plug holes with a telescoping magnet to see if there is anything in there before putting the new plugs in.
I'm worried about those tips. They don't just evaporate, and had to go somewhere. Anyone seen anything like this?
You could have lean spots in your A/F... could be lean at part throttle but not at WOT... stuff like that. I would dyno the car or tune it with some sort of wideband as soon as you can. It's easy to hurt an FI engine.
Yep, theres pics in the link in my sig too, friends Nitrous runs caused them.
Burnt off grounding straps = A) too hot a plug, what plugs were in there that burnt up? B) As John said, lean spots, just because its fat at WOT, idle and PT can be lean as hell, raising the temps and burning the grounding strap off, or you might have an initial rich (making the puff) and going lean, just because there is a puff of soot and no KR doesnt mean you aren't lean enough to melt straps. C) timing too advanced, also might not get KR but enough to burn them up. Trust me, any of three will cause it and can do it without KR!
Good luck.
BTW- Breaking in a new engine under 5psi of boost....got *****? Yes! Not my recommended path to new engine break in.
Charlie
Burnt off grounding straps = A) too hot a plug, what plugs were in there that burnt up? B) As John said, lean spots, just because its fat at WOT, idle and PT can be lean as hell, raising the temps and burning the grounding strap off, or you might have an initial rich (making the puff) and going lean, just because there is a puff of soot and no KR doesnt mean you aren't lean enough to melt straps. C) timing too advanced, also might not get KR but enough to burn them up. Trust me, any of three will cause it and can do it without KR!
Good luck.
BTW- Breaking in a new engine under 5psi of boost....got *****? Yes! Not my recommended path to new engine break in.
Charlie
Any time you run boost, you should not only log the entire run, but monitor it in real time. Your problem would sound unbelievable on a NA motor, but things like that can easily happen with a couple of lean spots in your fuelng under boost. You could easily be rich in one area, but dangerously lean in another.
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Thanks for the replies, guys. I just got my new plugs in, and am inside getting warm and dry before firing the engine. This is my first time changing plugs on an LS1. All I can say is that GM engineers must hate the people who work on these things all the time. I'd like to personally kick the **** out of the engineer who decided to use the cute sharp 10mm bolts on the coil pack brackets. Nice spikes and all. There are a lot of sharp spots that could be rounded off without spending a lot of R&D $$$. Luckily, the damn thing runs good enough that it's still worth it, but one of my buddies with a cobra was laughing at me.
I've got HPTuners hooked up and will do some logging. Assuming I haven't screwed anything up, I'll take it a little easier and send my tuner some logs before driving it much or making WOT runs. The engine has about 600 miles on it, so hopefully with my forged internals, I haven't toasted anything yet. When I can, I'll have an exhaust bung welded in for a wideband O2 and will probably get an LM1.
One other interesting point was that the car was stumbling at about 3000rpm-WOT. Below 3000 rpm, in "cruise" mode, I was fine. My tuner told me that the stumbling is usually more indicative of a lean condition than rich. Of course, I am not under boost at this point.
You know, I rattled a piston in my original motor after installing the turbo. Do you think my knock sensor could be bad, or can bad things really happen this quickly?
I've got HPTuners hooked up and will do some logging. Assuming I haven't screwed anything up, I'll take it a little easier and send my tuner some logs before driving it much or making WOT runs. The engine has about 600 miles on it, so hopefully with my forged internals, I haven't toasted anything yet. When I can, I'll have an exhaust bung welded in for a wideband O2 and will probably get an LM1.
One other interesting point was that the car was stumbling at about 3000rpm-WOT. Below 3000 rpm, in "cruise" mode, I was fine. My tuner told me that the stumbling is usually more indicative of a lean condition than rich. Of course, I am not under boost at this point.
You know, I rattled a piston in my original motor after installing the turbo. Do you think my knock sensor could be bad, or can bad things really happen this quickly?
Lean pops sound sharp and distinct... they come out the intake more often. Rich pops are usually out the tailpipe.
Evidence points to potentially being lean, so I would richen it up and go from there.
Evidence points to potentially being lean, so I would richen it up and go from there.
The sensor should be fine, of course I wouldnt test it by attempting to get a KR response! Normally they will over activate rather than not, at least from my readings on here and elsewhere. Definatley change the plugs, smaller gap too. Then add some fuel and check timing probably need to pull a few degrees. When your logging, if you see it getting lean at all, back out, add fuel immediately, and try agiain. You could be fine now, even after the burnt plugs, but for how long is anyones guess!
Good luck.
Charlie
Good luck.
Charlie
