new cam in and cant get it to idle
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I just put my new cam in its a 230/243 dur 631/631 lift with a 114 lsa.
I cant get to idle at all i have adj the idle spark advance the base running airflow and the idle adaptive spark control overspeed and underspeed.
I have it running really rich right now at idle and when i drive around my wideband is reading in the 10.0 to 11.5 range.
Ok when i am driving around it is surging like crazy and has no power. At one point the car was surging so bad that the whole car was bouncing back and forth. where should i start and what is going on?
I cant get to idle at all i have adj the idle spark advance the base running airflow and the idle adaptive spark control overspeed and underspeed.
I have it running really rich right now at idle and when i drive around my wideband is reading in the 10.0 to 11.5 range.
Ok when i am driving around it is surging like crazy and has no power. At one point the car was surging so bad that the whole car was bouncing back and forth. where should i start and what is going on?
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ive herd of drilling a small hole in the TB to allow it to get more air to idle a bit higher which is sometimes needed when installing a big cam but make sure you start with a very small hole until you get it to idle or it could idle way too high. I dont know this from experience but i have herd of it so it would be best to hear from others that have experience with this issue. Also could be in your tune sounds like you need to lean it out a bit at idle but it could just need more air.
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do not drill a hole this is a bad idea thats what your iac motor is for. people have cams far more wilder than that idling and driving close to stock. start with your afr since your not running alcohol. at the richest n/a should be 12.0 to 1. then add some timing but just a few degrees through out each cell and watch your tuning software to see if your computer starts pulling it. also you need to work on the tables you mention. i am far from an expert so i cant really help but the above mention stuff is pretty much the basics someone here should be able to help or you could try the hptuners forum at their site.
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No, no drill.
Sit there with the scan tool for a while. Use the bidirectional
controls to force it to idle right and learn what it's looking
for.
You can set the IAC up to 127 at least. That's enough air.
Provided you fuel and spark it right, so next play with the
commanded AFR. Bump it up or down and learn from the
response. Keep at it until you find the lowest MAP reading.
Look at the AFR and what the wideband says. Big skew
means you have probably an airflow error (hopefully no
blind injector swap in the mix, one thing at a time).
Both in agreement, you now know the roughly right AFR,
Now push on spark up and down to find a new min MAP.
This is best spark. Now you need to back off maybe 10
degrees, and give maybe 5 degrees to the adaptive spark
underspeed when you turn that back on. If you're maxed
on advance then some of these clean-it-up features are
defeated.
Now you have right answers for air (read g/sec at 127
IAC and RPM, you can dial down IAC and re-refine about
your target idle RPM. Even better "right answers".
Now you are ready to mess with tables. Fix any airflow
errors, first off. Hopefully the good AFR is somewhere near
stoich, but maybe slightly lean will be indicated with a big
overlap cam. If lean you will want to lower the O2 switch
voltages to try and get closed loop to be about the same
as ideal-indicated. Get that stuff tightened up. Put the good
airflow, plus maybe a g/sec, into the best-fit table cell and
move the rest proportionally. Change the idle advance tables
to the best-10 number in the idle-RPM-CylAir cell and dress
the rest by the same adder.
At this point the motor should be happy to idle on its own with
no finger-poking. If not I guess you have to go back to scan
for what got lost.
real g/sec airflow the motor needed, so scale the base
running airflow based on this going by the cell closest to
conditions of the data pull (IAT, ECT, etc.). I prefer to add
a bit of padding so it guesses in a good direction, not the
death spiral, and let the RPM loop pull it down.
Sit there with the scan tool for a while. Use the bidirectional
controls to force it to idle right and learn what it's looking
for.
You can set the IAC up to 127 at least. That's enough air.
Provided you fuel and spark it right, so next play with the
commanded AFR. Bump it up or down and learn from the
response. Keep at it until you find the lowest MAP reading.
Look at the AFR and what the wideband says. Big skew
means you have probably an airflow error (hopefully no
blind injector swap in the mix, one thing at a time).
Both in agreement, you now know the roughly right AFR,
Now push on spark up and down to find a new min MAP.
This is best spark. Now you need to back off maybe 10
degrees, and give maybe 5 degrees to the adaptive spark
underspeed when you turn that back on. If you're maxed
on advance then some of these clean-it-up features are
defeated.
Now you have right answers for air (read g/sec at 127
IAC and RPM, you can dial down IAC and re-refine about
your target idle RPM. Even better "right answers".
Now you are ready to mess with tables. Fix any airflow
errors, first off. Hopefully the good AFR is somewhere near
stoich, but maybe slightly lean will be indicated with a big
overlap cam. If lean you will want to lower the O2 switch
voltages to try and get closed loop to be about the same
as ideal-indicated. Get that stuff tightened up. Put the good
airflow, plus maybe a g/sec, into the best-fit table cell and
move the rest proportionally. Change the idle advance tables
to the best-10 number in the idle-RPM-CylAir cell and dress
the rest by the same adder.
At this point the motor should be happy to idle on its own with
no finger-poking. If not I guess you have to go back to scan
for what got lost.
real g/sec airflow the motor needed, so scale the base
running airflow based on this going by the cell closest to
conditions of the data pull (IAT, ECT, etc.). I prefer to add
a bit of padding so it guesses in a good direction, not the
death spiral, and let the RPM loop pull it down.
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OK well then what could cause me to stay in open loop? I know the rear O2s have nothing to do with speed density but i had to tune in speed density to be able to tune the ve tables and i couldn't get it to go into closed loop to be able to tune the maf.
and i have been tuning for a while now and have done a few cammed vehicles i am just trying to see if this is mechanical or a tuning issue i don't see.
and i have been tuning for a while now and have done a few cammed vehicles i am just trying to see if this is mechanical or a tuning issue i don't see.
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There may be other issues, like crusty sensors or just a
bunch of bad learning, that whack the closed loop mode.
But you can zero the trims and observe that as well, in
open loop (may want to defeat closed loop by the ECT
threshold value). Look for them to start switching randomly
(the fronts) as you start to get your fueling close to right.
bunch of bad learning, that whack the closed loop mode.
But you can zero the trims and observe that as well, in
open loop (may want to defeat closed loop by the ECT
threshold value). Look for them to start switching randomly
(the fronts) as you start to get your fueling close to right.
#15
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Your O2s appear to be unhooked in your log. There is little useful information in the log, there is no wideband, no commanded AFR, no idle airflow PIDs, no MAF freq..
What are you asking for (AFR wise) when it's rich? What is in the OLFA?
I would look at your file but you are using a beta version of the software and I don't use it on any of the laptops that I tune on (really meaning this one
) It's odd that I could even open your log file. I would try and help, but between the log and the PCM image...
What are you asking for (AFR wise) when it's rich? What is in the OLFA?
I would look at your file but you are using a beta version of the software and I don't use it on any of the laptops that I tune on (really meaning this one
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#16
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Your O2s appear to be unhooked in your log. There is little useful information in the log, there is no wideband, no commanded AFR, no idle airflow PIDs, no MAF freq..
What are you asking for (AFR wise) when it's rich? What is in the OLFA?
I would look at your file but you are using a beta version of the software and I don't use it on any of the laptops that I tune on (really meaning this one
) It's odd that I could even open your log file. I would try and help, but between the log and the PCM image... ![Sad](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_sad.gif)
What are you asking for (AFR wise) when it's rich? What is in the OLFA?
I would look at your file but you are using a beta version of the software and I don't use it on any of the laptops that I tune on (really meaning this one
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
![Sad](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_sad.gif)
Sorry for the hijack, Back to your regularly scheduled programming......
#17
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OP,
You have a custom OS applied, and your VE table looks like this......
![](http://i125.photobucket.com/albums/p58/edcmat-l1/VE.jpg)
You need to copy and paste your VE from your previous tune into this one.
Need to copy over your open loop table too. It's all 1.00s too.
PE is set to 1.25. Pretty rich for an NA motor.
Too much idle air.
You have a custom OS applied, and your VE table looks like this......
![](http://i125.photobucket.com/albums/p58/edcmat-l1/VE.jpg)
You need to copy and paste your VE from your previous tune into this one.
Need to copy over your open loop table too. It's all 1.00s too.
PE is set to 1.25. Pretty rich for an NA motor.
Too much idle air.
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ok this is what i have now and it idles real good for a couple of seconds then drops down to like 400rpm then goes back to idleing fine and it just keeps doing it over and over again and for the surging part it still is doing it. I added some timing down low but still not making a difference.