Who all is getting the occasional phantom P0300 code? I'm more interested in the supercharged setups but turbo guys chime in too. Wanting to know if you're running gm reflash, hpt tune, or standalone as well. I thought this issue was due to a bad injector harness but I replaced it and still have the issue. I'm running NGK LTR71X-11 (6510) plugs carefully gapped to something like 42 (dont remember 100
with probably around 10k on them. I have another icm I can try too.
Any information/discussion is appreciated gentlemen.
"In Oldskool we trust"
Stupid question...does that cause the check engine light to come on and stay on or flicker onand off like the trac control? Just want to make sure mines not misfiring.
Yellow:
2 steps cooler susally will not cause this problem, however if the plug is too cool it may from fuel fouling...
How much boost are you producing from that M62? usually we reccommend 0-10 psi 1 step cooler and 10- 18 psi 2 steps cooler, also depending on the boost level that gap seems a bit wide.
My set up is at around 15psi and we are at 0.030".
It will just come on and stay on until the code is cleared or the drive cycle is refreshed. I'm not even 100% sure it's actually misfiring, or at least if it is it's definitely not all the time and definitely not when it counts.
"In Oldskool we trust"
I'll admit I dont know much so I'll suggest obvious things. Since this started after the 3.1 and its not the harness I would say to change out the injector like you said (if you didnt already) and see what happens. I'd also gap them tighter...im running 6509 @ .036
Now that you guys mention it I'm 99.9% sure I gapped them to .032. I know a lot of people say you shouldn't gap them that low or gap them at all because ngk says so and all. I was super careful and inspected the electrodes afterward so I really don't see an issue there.
Jason, thanks for the info. I'm making 12-13psi of boost consistently. I'm wondering, though, if that is my issue because it only happens at idle or low rpms/speed and I do have some ridiculous fuel pressure (75psi at idle and probably around 85 at 6k). Maybe I'll swap that injector out and the ICM and drive it for a while.
"In Oldskool we trust"
I don't know that you really need the 2 steps colder on the 3.1 pulley. When I was on pretty much your exact set up with basically the same tune, I ran the 1 step colder, NGK LTR61X-11...6509 I think. Didn't re-gap them, ran them as is out of the box, never had any issues at all.
I actually still have 3 of mine (#4 died when the valve kissed the piston), if you want those and just buy a fouth they're all yours..figure that way it saves you a few bucks if it turns out to not be the issue. Only had like 1000 miles on them.
I was having some issues with misfires running the 2.8? pulley. I thought it was my plugs so I bought new 1step colder plugs and gapped them, but i don't remember what., 36 or 38 rings a bell, from 40. Doesn't matter, didn't help. I went aback to work on the tune and it hasn't been back since. IIRC it was missing at low rpm/throttle and I tweaked my injector constant and went a touch rich near idle. If you're running that kind of fuel pressure at idle, than you might be demanding a crazy short pulse at low rpm. What size injectors are your running?
Yellow,
I think I talked to you when you called us (NGK) didn't I?
Negative, but were they having the same problem?
By the way, huge development. It happened again tonight while I was at idle. Car was warm but it was still within a few minutes of start up as usual. While idling it bobbled for just a split second and threw both a p0300 code and a p0303 for cylinder 3. The good news is that definitely narrows it down to cylinder 3 and now I actually have physical evidence of some kind of misfire. Going to change plugs and that injector and see what happens. Almost wanting to swap the injector to another cylinder and see what happens.
"In Oldskool we trust"
Y3llowCav wrote:Almost wanting to swap the injector to another cylinder and see what happens.
That's where I would start
I was getting an 0300 and 0302, I flopped injectors and plugs and it was no help. What size injectors are you running? I would bet it is a fueling issue not spark, more specifically, demanding too short of an injector pulse.
yellow
I see that the guy i talked to was running a 2 step cooler plug and had this issue... I would try a 1 step hotter plug. I would be willing to bet that when you oull the plug out of the opposing cylinder it is carbon or fuel fouled. The car at idle will most likely do this as there is no load on it and the plugs aren't seeing enough heat to clean off the insulator. Pull one plug and take a picture or just visually look at it.
Thanks Jason. I have those plugs on the way, ill definitely keep you guys updated.
"In Oldskool we trust"
jason norwood wrote:Yellow:
2 steps cooler susally will not cause this problem, however if the plug is too cool it may from fuel fouling...
How much boost are you producing from that M62? usually we reccommend 0-10 psi 1 step cooler and 10- 18 psi 2 steps cooler, also depending on the boost level that gap seems a bit wide.
My set up is at around 15psi and we are at 0.030".
I have 1 step colder with 14psi and have knocks issues at high rpm... I will try 2 step colder I think!
Y3llowCav wrote:Now that you guys mention it I'm 99.9% sure I gapped them to .032. I know a lot of people say you shouldn't gap them that low or gap them at all because ngk says so and all. I was super careful and inspected the electrodes afterward so I really don't see an issue there.
For my problem od knocks I have test gap to .024 without any issue of misfire and original gap was .044
Ouffffff..... I tested**** sorry for bad english
i had seen that damm 300, 302, and 304 codes my set up is 80 lb EV1 injectors, fuel regulator set to 65 at boost, ngk 1 step colder gapped as original from the box no change on that, I get those codes whenever i run my cut out open if i run regular 2.5 exhaust, pacesetter 4-1 header, no CAT just a 12inch resonator. it doesn't throw those codes but last week i had some concerns because i started getting the codes without pushing the car n i decided to put half of a can of sea foam to half a tank of gas with in a week i noticed a huge difference on the car also i had notice that if you change the place you pump your gas from it will help i read in different places the its better to pump gas from other places because of the gas additives they put on. also run sea foam on the vacuum it helps a lot. btw 10 psi of boost
Man, you can't catch a break sometimes. Glad to see you've got it possibly narrowed down to a single cylinder issue though.
oldskool wrote:Man, you can't catch a break sometimes. Glad to see you've got it possibly narrowed down to a single cylinder issue though.
lol you're telling me brother. Although it still drives well and pulls hard(as the dyno proved) so I guess it could be worse. I'll keep you posted on any progress.
"In Oldskool we trust"
You gonna try swapping the injectors?
Update time. Upon further investigation I found this:
Took it all apart and used teflon sealant on all the fittings. Far as I can tell, no leaks after that tlc. The bottom fitting going into the rail was hand tight so I'm assuming that's where the problem was. Not sure how I missed that the first time..
Anyway, I also pulled the number 3 plug and snapped some pictures. Looks good to me, could be a little white/lean but I think that's being picky. Didn't pull the others for comparison as it was starting to rain.
While I was there I changed out the #3 injector with a spare just because. Drove around for a while and haven't had any trouble so far on multiple drive cycles. Hopefully that small leak was at fault. Results to follow after driving around for a few weeks. Still have those ngk 6509 plugs on their way too.
"In Oldskool we trust"
Sweet, hopefully that fixed the problem
