I need help!! Tuning issues... Spark??
12-17-2008 | 06:45 AM
#41
Not quite, the Cam sensor will be on his front timing cover since he has a LS2 block.
Check your harness for your cam position sensor/MAP sensor, maybe too tight at the back of the motor/getting pinched, as why you're seeing cutout at 4K rpms.
Also, do the Crank Relearn Procedure again, as that must be done when you install a new motor. Doesn't matter if you have the same PCM, you have to allow the PCM to learn the new reluctor so it can match up the firing sequence properly, and also check the sensor and MAKE sure its not damaged.
Check your harness for your cam position sensor/MAP sensor, maybe too tight at the back of the motor/getting pinched, as why you're seeing cutout at 4K rpms.
Also, do the Crank Relearn Procedure again, as that must be done when you install a new motor. Doesn't matter if you have the same PCM, you have to allow the PCM to learn the new reluctor so it can match up the firing sequence properly, and also check the sensor and MAKE sure its not damaged.
1st, the cam sensor won't matter at WOT. Matter of fact, you can unplug it and all it will do is be a little harder to start. It will perform normally once started though. It will kill the tach though.
2nd, a crank relearn has nothing to do with performance. All it is there for is misfire information. It will not, under any circumstances, affect performance, whether it is performed or not.
The ONLY TIME misfire detection is prevented is IF THE CRANK RELEARN CODE IS SET. You can go in and turn the code off, and you will still have misfire detection.
Now, as far as the problem you're having, without a tune, runlog, and dyno graph, it's anyone's guess. I would suggest you crank up the coil dwell and see what that does. It shouldn't need it being an NA motor, but hey, I've run into dumber stuff.
Could be a valve spring issue too. Again, hard to diagnose with no real data.
12-17-2008 | 08:57 AM
#42
This some bad info here.^^
1st, the cam sensor won't matter at WOT. Matter of fact, you can unplug it and all it will do is be a little harder to start. It will perform normally once started though. It will kill the tach though.
2nd, a crank relearn has nothing to do with performance. All it is there for is misfire information. It will not, under any circumstances, affect performance, whether it is performed or not.
The ONLY TIME misfire detection is prevented is IF THE CRANK RELEARN CODE IS SET. You can go in and turn the code off, and you will still have misfire detection.
Now, as far as the problem you're having, without a tune, runlog, and dyno graph, it's anyone's guess. I would suggest you crank up the coil dwell and see what that does. It shouldn't need it being an NA motor, but hey, I've run into dumber stuff.
Could be a valve spring issue too. Again, hard to diagnose with no real data.
1st, the cam sensor won't matter at WOT. Matter of fact, you can unplug it and all it will do is be a little harder to start. It will perform normally once started though. It will kill the tach though.
2nd, a crank relearn has nothing to do with performance. All it is there for is misfire information. It will not, under any circumstances, affect performance, whether it is performed or not.
The ONLY TIME misfire detection is prevented is IF THE CRANK RELEARN CODE IS SET. You can go in and turn the code off, and you will still have misfire detection.
Now, as far as the problem you're having, without a tune, runlog, and dyno graph, it's anyone's guess. I would suggest you crank up the coil dwell and see what that does. It shouldn't need it being an NA motor, but hey, I've run into dumber stuff.
Could be a valve spring issue too. Again, hard to diagnose with no real data.
Adrian
12-17-2008 | 09:34 AM
#43
Thanks for the clarification! I guess I had my information skewed. Question though, if you're throwing the Crank relearn code, because of misfires at idle, which is the result of improper crank angle measurements, how does that NOT affect performance at all? Have you done back to back dyno testing? I guess I don't see how if firing is not timed properly because the trigger is off how it won't affect performance, and pretty drastically as well. Or do I just need to pick up a tuning book and educate myself? haha.
Adrian
Adrian
First off, the crank relearn is so the computer can detect variations in crank shaft speed at higher RPMs, not idle.
Second, you can turn the code off, and never ever worry about it. You'll still have misfire detection, as it's not interrupted UNLESS THE CODE IS SET.
PS you don't need a tuning book, just a thorough understanding of OBDII.
12-17-2008 | 10:27 AM
#44
You do not throw a crank relearn code because of misfires at idle. That's two totally different things. If it's misfiring, it will have a misfire code, not a crank relearn code because of a misfire.
First off, the crank relearn is so the computer can detect variations in crank shaft speed at higher RPMs, not idle.
Second, you can turn the code off, and never ever worry about it. You'll still have misfire detection, as it's not interrupted UNLESS THE CODE IS SET.
PS you don't need a tuning book, just a thorough understanding of OBDII.
First off, the crank relearn is so the computer can detect variations in crank shaft speed at higher RPMs, not idle.
Second, you can turn the code off, and never ever worry about it. You'll still have misfire detection, as it's not interrupted UNLESS THE CODE IS SET.
PS you don't need a tuning book, just a thorough understanding of OBDII.
12-22-2008 | 08:31 PM
#45
Thread Starter
Joined: Aug 2005
Posts: 2,451
Likes: 0
From: Pasadena, CA
Problem solved!!
Guess what it was, the connector that plugs into the crank position sensor had a loose pin and that was causing it....
We fixed the pin and drove the car, after it fully warmed up..
The car for once, pulled straight up to 6000rpms, smoothly...
I made a pull in 2nd gear and 1st gear. it seems solid. So Issue fixed (unless this occurs again tomorrow)
But Im so happy its fixed...
Guess what it was, the connector that plugs into the crank position sensor had a loose pin and that was causing it....
We fixed the pin and drove the car, after it fully warmed up..
The car for once, pulled straight up to 6000rpms, smoothly...
I made a pull in 2nd gear and 1st gear. it seems solid. So Issue fixed (unless this occurs again tomorrow)
But Im so happy its fixed...
12-26-2008 | 05:39 PM
#50
Thread Starter
Joined: Aug 2005
Posts: 2,451
Likes: 0
From: Pasadena, CA
lol my 520 goal was like way in the spring of 2008, when I didnt even buy a cam for this motor yet.... For this car, if I touch 500rwhp, I will be very satisfied, but realistically Im hoping to make at least 480rwhp, if I make less, its not the end of the world, but 480 is the # I wanna reach AT LEAST...