rough idle issues everyonce in a while
rough idle issues everyonce in a while A few weeks ago I ported the intake manifold and throttlebody on my ls2 gto. It was fine for a few days and then an idle issue popped up and a lean code has also came up. The thing is. The idle issue is only everyonce in a while. Sometimes a quick whack of the throttle will help. And I used my code reader today and it had a pending lean code but didn't turn the cel on. I cleared it and it seemed to be fine for the rest of the day.
What I have done sofar is check for intake leaks and pull the manifold and checked the gaskets. I also tryed starting fluid around the sealing points with no luck getting the idle to change. The car is not tuned could that be an issue? I was told it was close to the lean side with just headers before doing the intake manifold. And I figure if its an intake leak I wouldnt be so inconsistent. I plan to get new gaskets next but was just hoping for some more input. I am hoping its in the tune.
What I have done sofar is check for intake leaks and pull the manifold and checked the gaskets. I also tryed starting fluid around the sealing points with no luck getting the idle to change. The car is not tuned could that be an issue? I was told it was close to the lean side with just headers before doing the intake manifold. And I figure if its an intake leak I wouldnt be so inconsistent. I plan to get new gaskets next but was just hoping for some more input. I am hoping its in the tune.
So you had headers on without a tune as well?
Yeah once you start messing with engine airflow then the computer has a hard time adjusting..
Doubt you have a Intake leak, pretty hard to get one with these intakes..
Yeah once you start messing with engine airflow then the computer has a hard time adjusting..
Doubt you have a Intake leak, pretty hard to get one with these intakes..
Yeah. It was fine after headers. I had a guy with hp tuners turn off my second o2 sensors and he ran a couple data logs and said I was a little lean but not scary dont drive the car bad. I am hoping its just the ported intake thats causing the idle issue without a tune and not a vac leak. I did a pretty radical job on the manifold and removed the center posts. I plan to remove the manifold this week plug the holes and attempt to pressure test it. When I removed the center posts I was left with holes on the bottom of the manifold. I epoxyed some plastic patches to the bottom outside of the manifold. Then filled the voids from the inside. I did pressure test the manifold before assembly and it was ok before I put it back on.
I just figured it was weird that the issue only comes up after a hundred miles or so. And clearing codes seems to be temporary fix. Which is leading me to believe its not a vacuum leak. I am know it will need tuned. But dont want to show up to a tuner with the chance that this is a real issue and end up chasing my tail.
I just figured it was weird that the issue only comes up after a hundred miles or so. And clearing codes seems to be temporary fix. Which is leading me to believe its not a vacuum leak. I am know it will need tuned. But dont want to show up to a tuner with the chance that this is a real issue and end up chasing my tail.
I doubt its a intake leak dude, if you pressurized it then its fine.
the intake is under vacuum since your NA, if it had a major leak the only way I think it would be exposed is if you were going WOT or if you were boosting (FI)...
you need a tune, if your lean then your lean.. the rough idle can be your computer trying to compensate for the mods you did.. and since its an ls2 engine which are super choked up from the factory then its not used to the air that its receiving right now lol..
goodluck
the intake is under vacuum since your NA, if it had a major leak the only way I think it would be exposed is if you were going WOT or if you were boosting (FI)...
you need a tune, if your lean then your lean.. the rough idle can be your computer trying to compensate for the mods you did.. and since its an ls2 engine which are super choked up from the factory then its not used to the air that its receiving right now lol..
goodluck
bump.
Still isnt tuned. I know, i am a broke di*k slacker. But the issue has gotten WAY worse. I figured out how to use my scanner and I can watch my fuel trims with it. my short term are reading 50% and long term trims are at 25% both at idle in i believe closed loop. o2 voltage seems to read .08 ish volts. I Did pull the manifold back off twice, both times checking for leaks and cracks and the last time i pulled it off I went ahead and replaced the runner gaskets. I have tryed the starter fluid around all possible leak points and the car is running on all 8 cylinders.
Unlike before when i originally posted this thread, i was only getting lean codes for bank 1 and now i get them for both. I have has a couple random missfire codes, and heated switching codes at the o2 sensors. sometimes bank one seemed to be leaner so i swaped the o2s side to side to see if the issue would follow but it didnt.
Also, before clearing the codes or disconecting the battery would help. but not the case anymore. I also tryed swaping mafs to a good one that I only replaced because the screen was messed up. Still no change.
Anyone have anyother tricks i can try? I want to try o2 sensors next but dont wanna be that guy that just throws parts at it untill its fixed. I am not convinced its just the tune, because it ran great for a month or so before these issues started poping up. Any help would be greatly appreciated!
Still isnt tuned. I know, i am a broke di*k slacker. But the issue has gotten WAY worse. I figured out how to use my scanner and I can watch my fuel trims with it. my short term are reading 50% and long term trims are at 25% both at idle in i believe closed loop. o2 voltage seems to read .08 ish volts. I Did pull the manifold back off twice, both times checking for leaks and cracks and the last time i pulled it off I went ahead and replaced the runner gaskets. I have tryed the starter fluid around all possible leak points and the car is running on all 8 cylinders.
Unlike before when i originally posted this thread, i was only getting lean codes for bank 1 and now i get them for both. I have has a couple random missfire codes, and heated switching codes at the o2 sensors. sometimes bank one seemed to be leaner so i swaped the o2s side to side to see if the issue would follow but it didnt.
Also, before clearing the codes or disconecting the battery would help. but not the case anymore. I also tryed swaping mafs to a good one that I only replaced because the screen was messed up. Still no change.
Anyone have anyother tricks i can try? I want to try o2 sensors next but dont wanna be that guy that just throws parts at it untill its fixed. I am not convinced its just the tune, because it ran great for a month or so before these issues started poping up. Any help would be greatly appreciated!
