Hey guys I have a 2003 cavalier built motor with a level 5 Hahn racecraft kit. I did the ln2 coil swap with summit coils and msd wires and I still break up in the high rpms. I'm running 28psi and it breaks up but if I run 20psi it doesn't break up!!! I can't figure out what it is?
What plugs are you running and what are they gapped at?
I'm run Ngks 2 step colder gapped at 0.25
have you thought about using some coils with a lil bit more oomph?
-Trailblazer SS - not so custom 6.0L - custom intake - custom tune
- (1) 2.4L on an engine stand (1) blown trans (2) good quad trans (1) eco trans = party
my bet would still be on plugs. Sounds like you are blowing them out under high boost/rpm
Tony T wrote:I did the ln2 coil swap with summit coils and msd wires and I still break up in the high rpms. I'm running 28psi and it breaks up but if I run 20psi it doesn't break up!!! I can't figure out what it is?
This could be several different things causing this but I need more information to be able to try and address what it might be.
*You said it is Misfiring........ any idea if you are getting any knock as well and if so how much timing is being pulled?
*What is your air fuel ratio just before it cuts?
*You have no profile so what are you using for ignition I.E. MSD part number.
*The weakest link in the ignition setup you have briefly described is definitely the 2200 dual post coils (assuming I read this correctly). Even if this is not the issue I highly recommend you move to at least the MSD 8224 GM two post Blaster coils. 28 psi is even high for those. Again I am not entirely certain what you are running for an ignition setup because I apparently am not familiar with whatever is considered the "LN2 Coil Swap" Secondly you are really pushing the efficiency of the 20G when you near 30 psi assuming that is what you are still using. Some of that pressure may actually be a result of back pressure build up. Meaning your pushing far more air than you can physically consume in simple terms.
*Another thing to note that .25 plug gapping is REALLY tiny. There is definitely such thing as too small of a gap because remember the smaller you go with this gap the weaker the spark is. You gap em smaller to overcome the resistance of so much pressure but eventually you will exceed a threshold in both categories and the benefit of the smaller gap dissipates. Essentially it may be too week to breach the gap under so much resistance (spark blow out) as a result of weaker coils and such a small gap. There's a fine line between too much and two little in this case.
*Do you have access to an emissions exhaust sniffer? This will be the only real way to determine what type of misfire you are experiencing which in turns helps diagnose what exactly is happening. This is likely not an option for you but its incredibly helpful so long as you understand the readings.
ASE Master Certified Automotive Technician
Well when I'm data logging on hp tuners it doesn't misfire it just breaks up! There is no misfire, no knock just break up I get around 6000rpm and it just breaks up and the rpms won't climb it just stops. Now for afrs I'm around 10.3 to 10.7 at full trottle. Now for ingition I'm using stock just upgraded coils and wires. I use the 2200 coil setup so I could upgrade coils. The coils are 40000 volts
Also about a month ago I was running 28psi no problem mo break up nothing. It just started breaking up out of no where. I'm also running the Hahn portfuller
Well if you're not seeing ANY misfire or knock readings while data logging that makes this a lot more difficult. I wish I knew what exactly you were experiencing when you say "it's just breaking up". I mean I know what I refer to as break up but I don't know what you might refer to be this symptom. I mean this is a dumb question probably but you didn't accidentally somehow mess with your spark cut in HPT did you? It is ironically close to the stock rev limit parameters.
How many miles do you have on those NGKs? I run the same ones and mine are pretty well dead around 10K with high boost. They are pretty much like clockwork. They are fine with lower boost but if I have a lot of miles on em they will cut out over 15 psi. I actually just replaced mine again and everything is back to normal w/ 15+ psi. Surprisingly They lasted a half season of road coursing this year too. 4th set on this one in 2.5 years.
I was gonna say you may have some rich misfires with those AFRs but with no misfire readings that's a little odd. So your telling me your knock datalog is flawless all the way to 23+ psi? If this is the case and the misfires are pretty well undocumented then it's pointing more and more to ignition. The only way to see what the ignition system is doing would be to hook it up to an ignition lab scope but again your prolly lacking that ability. That way we could see exactly what is happening in the ignition system. Whatever it is it is effecting all 4 cylinders simultaneously from what it sounds like.
Nothing you have mentioned makes me think the portfueler is involved in anyway nor fuel at all to be honest.
ASE Master Certified Automotive Technician
I have a stock top end and rev limiter is set at 6800rpm so maybe it is spark cutout. And I have maybe 5000miles on my plugs but should I open the the gap a little?
Also thank you for help!! I'm dump founded right now with this @!#$ I'm about to just give up!
I would get another set of plugs. Plugs are cheap. I keep at least 1 extra set around.
FU Tuning
Screaming for Mercy!! wrote:I would get another set of plugs. Plugs are cheap. I keep at least 1 extra set around.
I don't know if I would call em cheap at nearly $10 ea. but I do agree that it may be time to swap em out.
5k is a little pre-mature (mine are like clockwork at 10k) with the experience I have had with mine but you're also running a lot of resistance through the whole ignition system. The plugs will look fine most likely when you pull them but I do recommend you look to see if you have one that's a little different looking than the rest. That will help indicate a possible candidate for problems (if you can take pics of all 4 that will be helpful to see how your engines been running over the 5k of abuse on those plugs). I really don't think it is just one cylinder though because it sounds as though all 4 are being affected.
Best place I have had luck finding the NGK LTR7IX-11s in stock is usually NAPA for local. If you have some time though www.sparkplugs.com is gonna be your cheapest route and like John mentioned keeping an extra set on hand is a good idea if you have an extra $40
Oh just so you know your stock tachometer is a little slow when it comes to indicating actual RPM when you get into this power range. The engine essentially revs faster than the stepper motor can go in the gauge cluster. So you may very well be hitting higher RPMs than you can see. The actual RPMs will show up on the HPT datalogger correctly so you may wanna go by that to see what it's actually doing. Another thing to keep in mind is that you may have HPT (or whoever tuned it) set to start Spark Ramp out to begin around 6000 and completely cutting at 6800. Depending on how the RPM settings are setup this will give you what feels like a smooth ceiling where the car just feels like it reaches the top and stays ther, just holding that RPM. It does this because I have the spark setup to re-engage like 10PRM below the cutout. This eliminates that notorious rev limit BAH....BAH.....BAH......BAH.....BAH.....BAH. Just goes to the top and holds.
ASE Master Certified Automotive Technician
Quote:
Another thing to keep in mind is that you may have HPT (or whoever tuned it) set to start Spark Ramp out to begin around 6000 and completely cutting at 6800. Depending on how the RPM settings are setup this will give you what feels like a smooth ceiling where the car just feels like it reaches the top and stays ther, just holding that RPM.
what u just said is what is happen with my car!!!!!!
this is what is happen with my car as soon as my reaches 6000rpm it just stops it wont go up in rpms.
I would say that this is most likely what it is then BUT you said it wasn't doing it before so this doesn't make sense unless someone made a change. Have you been playing around in HPT recently or anyone?
You know whats really surprising me more than anything now that I think of it is that you are not floating valves.......... Usually when you get into that pressure range you will float valves on the stock valve springs. You did say that your head is stock correct? Floating valves can cause some weirdness too but not really like your describing.
ASE Master Certified Automotive Technician
$10 a plug is too much. I use NGK's v-power usually $1.79 a plug.
FU Tuning
Yes I am using a stock head and yes I have been playing hptuners. I'm going to have to look at my tune and see what I f'ed with. I will keep u updated. My laptop is in my girlfriends car and she is gone till Saturday!! Damn!
i also use the LTR7IX-11's
Screaming for Mercy!! wrote:$10 a plug is too much. I use NGK's v-power usually $1.79 a plug.
Ahh well that explains it. No I would definitely not recommend the V-Powers for this application. What he is using is the way to go for the eco but it is expensive. Iridium and two steps cooler. The V-powers are decent but not up to par for this application
ASE Master Certified Automotive Technician
CaliforniaDomestics wrote:Screaming for Mercy!! wrote:$10 a plug is too much. I use NGK's v-power usually $1.79 a plug.
Ahh well that explains it. No I would definitely not recommend the V-Powers for this application. What he is using is the way to go for the eco but it is expensive. Iridium and two steps cooler. The V-powers are decent but not up to par for this application
Sorry I disagree. I would not run Iridium for this. V-power or the coppers, but not Iridium
FU Tuning
Screaming for Mercy!! wrote:Sorry I disagree. I would not run Iridium for this. V-power or the coppers, but not Iridium
I'm curious of your reasoning?
Are you sure your not confusing iridium with platinum?
ASE Master Certified Automotive Technician
CaliforniaDomestics wrote:Screaming for Mercy!! wrote:Sorry I disagree. I would not run Iridium for this. V-power or the coppers, but not Iridium
I'm curious of your reasoning?
Are you sure your not confusing iridium with platinum?
I do not like Iridium because of how hard they are to adjust the gap. You have to be very careful to not bend the small tip while adjusting. In a turbo setup you could be adjusting the gap a decent amount at least in the begining.
I was always told your not suppose ot adjust the gap on Iridium plugs anyways. Also the price.
FU Tuning
Screaming for Mercy!! wrote:CaliforniaDomestics wrote:Screaming for Mercy!! wrote:Sorry I disagree. I would not run Iridium for this. V-power or the coppers, but not Iridium
I'm curious of your reasoning?
Are you sure your not confusing iridium with platinum?
I do not like Iridium because of how hard they are to adjust the gap. You have to be very careful to not bend the small tip while adjusting. In a turbo setup you could be adjusting the gap a decent amount at least in the begining.
I was always told your not suppose ot adjust the gap on Iridium plugs anyways. Also the price.
certainly no argument on all counts. They really are a pain to adjust because they are very stubborn and you do have to be very careful not to hit the tiny tip. They can be adjusted but they technically should only be adjusted slightly in either way from factory gapping. I personally gap em below the max of whats recommended (32) but I have yet to break the ground tip off......... knock on wood. Might have to give the V-powers a go to see if they hold up.
ASE Master Certified Automotive Technician
Just a thought... are Autolite's an option? I use AR103 for my 3800 swap and I have no issues with them, even the 103's would work.
Just throwing that out there, I realize it's a different engine and all...
Im running autolite iridiums now, basically the same thing as the 6IX-11 NGK, seems to work fine with the boost now.
I would recommend them, 6.99 a plug here.
