okay its been almost a month and I can't figure out why my car is throwing this CEL ( misfire in cyl 1,2,3,4 and ramdom misfgire. I cleared the dtc and it comes on again during normal driving. At first I couldn't figure out why it was throwing the Cel cuz I could not hear or feel a misfire. So I had to get a second opinion. I had somebody else drive it with both my race kal and street kal and he too did not feel nor hear anything abnormal. The car was fully tuned by Tim at xact dyno and it never had problems with the misfires til I made a road trip from phx to san diego (lots of hills) and it the CEL came on while coasting down hill.
Then I finally feel a miss when I was at the track Sat making a pass. It was in the middle of 4th at WOT..it was like a quick hesistation, like a quick pause.
any help would greatly appreciated.
this is what I'm running in my car. (02 acura rsx-s)
cn turbokit, 9:1 wiseco pistons, eagle rods, 650cc injectors (high impedance) intank fuel pump and return line, aeromotive fpr
I drive it on 11 psi daily with pump gas and on track day it is a 16psi withb race fuel. I replaced my plugs thinking they could be the problem and it wasn't.
random misfire in all cylinders
Well, if you're datalogs show your a/f doing allright, and your tune is still somewhat accurate, it sounds like your plugs may be messed up or you managed to damage your engine with excessive knock/detonation on that road trip. Did you have flash mil on knock detection enabled / see or notice any knocking?
2003 black RSX type-s / jrsc @ 12psi / methanol injection / aftercooled
nah no knocks and it was enabled. plugs look good and leak down was real good, I'm out of ideas some one said it could be a crank posistion sensor but wouldn't it throw a different CEL along with the misfires? here is a datalog from last night when the cel came on.
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Well, I've reviewed your datalog, and the only thing that really jumps out at me is that you are pig rich everywhere in boost. I've seen 11.2 and 11.3s in the log. The factory wideband isn't acurate lower than 11.5. I've ran 11.3 a/f before and removed around 5 - 7 % fuel before it even came up to 11.5. Did your tuner use a wideband in the tail or did he screw it into your down pipe / exhaust where your primary was? The reason I ask is because I've seen readings be quite a bit leaner near the tail, especially with a cat, which I'm assuming you don't have.
In any case, coasting down a hill, the car would simply cut fuel, so you wouldn't even fire in the first place, let alone missfire. I'm guessing that when you were climing the hill, you were running really rich and it missfired and happened to not come on until you started going down the other side.
That would line up with your hessitation at the track .. I bet you dump black smoke from your tail when in boost don't you?
Keep in mind, I'm not a tuner or mechanic, but I'd get that car to a dyno and...
1) verify your wideband readings vs their wideband readings in your primary o2 bung -- ie, compare your sensor in the bung to their sensor in the bung.
2) get some fuel tuning for boost as you're running really rich.
Once you've cleaned up the fuel tune, see if the cel comes back. Even at partial boost, say less than 1psi, you're a/f is off the scale rich. You may want to investigate columns 8-10 as well (N/A WOT) since if they were adjusted as well during your tune, those could be rich as well and cause strange problems if you hang out at part throttle right before boost.
In any case, coasting down a hill, the car would simply cut fuel, so you wouldn't even fire in the first place, let alone missfire. I'm guessing that when you were climing the hill, you were running really rich and it missfired and happened to not come on until you started going down the other side.
That would line up with your hessitation at the track .. I bet you dump black smoke from your tail when in boost don't you?
Keep in mind, I'm not a tuner or mechanic, but I'd get that car to a dyno and...
1) verify your wideband readings vs their wideband readings in your primary o2 bung -- ie, compare your sensor in the bung to their sensor in the bung.
2) get some fuel tuning for boost as you're running really rich.
Once you've cleaned up the fuel tune, see if the cel comes back. Even at partial boost, say less than 1psi, you're a/f is off the scale rich. You may want to investigate columns 8-10 as well (N/A WOT) since if they were adjusted as well during your tune, those could be rich as well and cause strange problems if you hang out at part throttle right before boost.
2003 black RSX type-s / jrsc @ 12psi / methanol injection / aftercooled
first off thanks for your advice this far....
my tunner used a wideband that screwed into the primary bung. the datalog was from his kal he sent me so I guess he added more fuel to it. I went through some of the trouble shooting guides in the helms and just remembered that I forgot to disconnect the stock fpr when I installed a walbro intank, I don't know if this would relate but one of the steps was to check for fuel pressure.
my tunner used a wideband that screwed into the primary bung. the datalog was from his kal he sent me so I guess he added more fuel to it. I went through some of the trouble shooting guides in the helms and just remembered that I forgot to disconnect the stock fpr when I installed a walbro intank, I don't know if this would relate but one of the steps was to check for fuel pressure.
I really doubt you have fuel system issues, but definatly run anything you can think of to ground.ikon671 wrote:first off thanks for your advice this far....
my tunner used a wideband that screwed into the primary bung. the datalog was from his kal he sent me so I guess he added more fuel to it. I went through some of the trouble shooting guides in the helms and just remembered that I forgot to disconnect the stock fpr when I installed a walbro intank, I don't know if this would relate but one of the steps was to check for fuel pressure.
2003 black RSX type-s / jrsc @ 12psi / methanol injection / aftercooled
Re: random misfire in all cylinders
[quote="ikon671"]okay its been almost a month and I can't figure out why my car is throwing this CEL ( misfire in cyl 1,2,3,4 and ramdom misfgire. I cleared the dtc and it comes on again during normal driving. At first I couldn't figure out why it was throwing the Cel cuz I could not hear or feel a misfire. So I had to get a second opinion. I had somebody else drive it with both my race kal and street kal and he too did not feel nor hear anything abnormal. The car was fully tuned by Tim at xact dyno and it never had problems with the misfires til I made a road trip from phx to san diego (lots of hills) and it the CEL came on while coasting down hill.
Then I finally feel a miss when I was at the track Sat making a pass. It was in the middle of 4th at WOT..it was like a quick hesistation, like a quick pause.
any help would greatly appreciated.
this is what I'm running in my car. (02 acura rsx-s)
cn turbokit, 9:1 wiseco pistons, eagle rods, 650cc injectors (high impedance) intank fuel pump and return line, aeromotive fpr
I drive it on 11 psi daily with pump gas and on track day it is a 16psi withb race fuel. I replaced my plugs thinking they could be the problem and it wasn't.[/quote]
I have the same problem. Newly installed greddy kit with new rc750cc injectors. When I first got the misfire codes I just thought it was because I was running way to rich. So I replaced the plugs and at the same time, removed quite a bit of fuel from the overall fuel trim in kpro. Then the car drove fine for about 3 days. Then it started again. Everytime I drive, misfire codes. I have not checked the plugs, but I am sure they are OK. One of the datalogs I did I was at mid to high 11's for my air/fuel at WOT. And the car runs fine. Any ideas??
Then I finally feel a miss when I was at the track Sat making a pass. It was in the middle of 4th at WOT..it was like a quick hesistation, like a quick pause.
any help would greatly appreciated.
this is what I'm running in my car. (02 acura rsx-s)
cn turbokit, 9:1 wiseco pistons, eagle rods, 650cc injectors (high impedance) intank fuel pump and return line, aeromotive fpr
I drive it on 11 psi daily with pump gas and on track day it is a 16psi withb race fuel. I replaced my plugs thinking they could be the problem and it wasn't.[/quote]
I have the same problem. Newly installed greddy kit with new rc750cc injectors. When I first got the misfire codes I just thought it was because I was running way to rich. So I replaced the plugs and at the same time, removed quite a bit of fuel from the overall fuel trim in kpro. Then the car drove fine for about 3 days. Then it started again. Everytime I drive, misfire codes. I have not checked the plugs, but I am sure they are OK. One of the datalogs I did I was at mid to high 11's for my air/fuel at WOT. And the car runs fine. Any ideas??
ikon671's injectors weren't RC, but we have seen this problem before. on large injectors it's difficult to open the pintel small amounts and quickly. that is why an idle ratio of 13:1 was suggested. when that didn't work, that's why they were flow tested and the problem was found. RCs are generally very good injectors, but you may have a bad one. the thing ikon671 forgot to mention was that not only did he have his injectors tested for max flow, he had them tested at <2ms at 45 psi. this is an idle and cruise opening time. that's where the problem was found. it's tough to find a shop that will test both, but you must with larger injectors. we have 550s that are guaranteed to do it and soon will have 800s. for testing we use Arizona TPI. do what ikon671 did if you can.