Cam Idle Surge - any solution?
08-26-2013, 09:13 AM
#1
Instructor
Thread Starter
Cam Idle Surge - any solution?
Hello all!
This is my first c6 corvette, coming from 2 other cammed C5's, I've never had this problem before and wondering if anyone has a solution or some information for me.
I just picked the car up last week, the previous owner gave me a short list of everything done to the car and I was told the performance parts were professionally installed and it was professionally tuned at IndyHP in Indianapolis. It is a 2005 LS2 car, the pars are: LG long tubes, no cats, X pipe, GLH catback, Vararam Intake, a 233/239 Cam (full specs on the cam are; 233/239 610/615 on a 110+3) and an AEM A/F meter (along with other suspension/cosmetic stuff).
My issue is a surge in idle at various times while diving the car as well as start up, again I've owned 2 previous cammed C5's and never ever had an issue with idle at any time so I don't have a clue as to whats going on. When I start this car (cold or hot) it cranks over, then feels like it wants to stall out right away but then goes into a nice lope around 800-900rpm just like it should. When I am driving, pretty much anytime I put the car into neutral (either from decelerating or just throwing it into N), it will surge down as low as 100-200RPM (mostly surges down to about 400, but will bounce back and forth between 400-1000 a few times before going back up and loping around 900RPM. I can sometimes help it by blipping the gas pedal when the RPMs dip down low where I think its going to stall out. It mostly happens when I come to a stop sign or red light, or in stop and go traffic, or if I am still moving but put the car into neutral, pretty much every time. Its annoying and hope there is a way to solve it. Another observation I've noticed is my oil pressure dips down when the idle surges, but I assume its normal behavior for the oil press to follow the RPMs like that.
I am calling around today to some local (and non-local) shops to see about getting the car re-tuned, although I am not sure this will solve my problem I still want to re-tune it so I know it has a safe and sound tune on it.
I drove the car 400miles home the day I bought it, and had 0 issues other than the idle surge. Yesterday I saw a CEL come up so I took it to my uncle's garage to scan it an it said something along the lines of: "bank 1 lean"
But I have YET to go WOT with the car since I have no proof the car was tuned right and honestly I do not know how to read this A/F gauge, I assume its to stay in the rich (green) when at WOT, but I am not doing that without a proper dyno tune - i'd rather be safe than sorry, i've heard of too many horror stories.
Let me know if anyone has any input to what my problem could be and if a proper tune will solve it or is this just the way some cam's are?
I can make a video of what it does to show you guys if that will help.
Thanks in advance!
edit: Does this sound like it could be a vacuum leak issue at all? I was speaking to one of the Tech's at my uncle's shop and he said it could be a vacuum leak causing the idle surge and CEL.
This is my first c6 corvette, coming from 2 other cammed C5's, I've never had this problem before and wondering if anyone has a solution or some information for me.
I just picked the car up last week, the previous owner gave me a short list of everything done to the car and I was told the performance parts were professionally installed and it was professionally tuned at IndyHP in Indianapolis. It is a 2005 LS2 car, the pars are: LG long tubes, no cats, X pipe, GLH catback, Vararam Intake, a 233/239 Cam (full specs on the cam are; 233/239 610/615 on a 110+3) and an AEM A/F meter (along with other suspension/cosmetic stuff).
My issue is a surge in idle at various times while diving the car as well as start up, again I've owned 2 previous cammed C5's and never ever had an issue with idle at any time so I don't have a clue as to whats going on. When I start this car (cold or hot) it cranks over, then feels like it wants to stall out right away but then goes into a nice lope around 800-900rpm just like it should. When I am driving, pretty much anytime I put the car into neutral (either from decelerating or just throwing it into N), it will surge down as low as 100-200RPM (mostly surges down to about 400, but will bounce back and forth between 400-1000 a few times before going back up and loping around 900RPM. I can sometimes help it by blipping the gas pedal when the RPMs dip down low where I think its going to stall out. It mostly happens when I come to a stop sign or red light, or in stop and go traffic, or if I am still moving but put the car into neutral, pretty much every time. Its annoying and hope there is a way to solve it. Another observation I've noticed is my oil pressure dips down when the idle surges, but I assume its normal behavior for the oil press to follow the RPMs like that.
I am calling around today to some local (and non-local) shops to see about getting the car re-tuned, although I am not sure this will solve my problem I still want to re-tune it so I know it has a safe and sound tune on it.
I drove the car 400miles home the day I bought it, and had 0 issues other than the idle surge. Yesterday I saw a CEL come up so I took it to my uncle's garage to scan it an it said something along the lines of: "bank 1 lean"
But I have YET to go WOT with the car since I have no proof the car was tuned right and honestly I do not know how to read this A/F gauge, I assume its to stay in the rich (green) when at WOT, but I am not doing that without a proper dyno tune - i'd rather be safe than sorry, i've heard of too many horror stories.
Let me know if anyone has any input to what my problem could be and if a proper tune will solve it or is this just the way some cam's are?
I can make a video of what it does to show you guys if that will help.
Thanks in advance!
edit: Does this sound like it could be a vacuum leak issue at all? I was speaking to one of the Tech's at my uncle's shop and he said it could be a vacuum leak causing the idle surge and CEL.
Last edited by SmittyChevy; 08-26-2013 at 09:16 AM.
08-26-2013, 11:06 AM
#2
Drifting
Could you have a vacuum leak? Possibly...
But you definitely have a tuning issue and the shop that did it might not be able to fix it. That cam is on a 107 ICL so expect a really choppy idle. Good tuning will fix your problems but don't expect it to feel smooth idling because that cam has +16 overlap to it. That means low rpm bucking will be something you have to learn to deal with putting around town. If it was my daily driver I would put a 224/236 115+2 XFI cam in it (with 0 overlap) and watch it make 8-10 less hp and drive like stock while still revving to the moon
But you definitely have a tuning issue and the shop that did it might not be able to fix it. That cam is on a 107 ICL so expect a really choppy idle. Good tuning will fix your problems but don't expect it to feel smooth idling because that cam has +16 overlap to it. That means low rpm bucking will be something you have to learn to deal with putting around town. If it was my daily driver I would put a 224/236 115+2 XFI cam in it (with 0 overlap) and watch it make 8-10 less hp and drive like stock while still revving to the moon
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JohnRR (09-02-2023)
08-26-2013, 11:21 AM
#3
Instructor
Thread Starter
Could you have a vacuum leak? Possibly...
But you definitely have a tuning issue and the shop that did it might not be able to fix it. That cam is on a 107 ICL so expect a really choppy idle. Good tuning will fix your problems but don't expect it to feel smooth idling because that cam has +16 overlap to it. That means low rpm bucking will be something you have to learn to deal with putting around town. If it was my daily driver I would put a 224/236 115+2 XFI cam in it (with 0 overlap) and watch it make 8-10 less hp and drive like stock while still revving to the moon
But you definitely have a tuning issue and the shop that did it might not be able to fix it. That cam is on a 107 ICL so expect a really choppy idle. Good tuning will fix your problems but don't expect it to feel smooth idling because that cam has +16 overlap to it. That means low rpm bucking will be something you have to learn to deal with putting around town. If it was my daily driver I would put a 224/236 115+2 XFI cam in it (with 0 overlap) and watch it make 8-10 less hp and drive like stock while still revving to the moon
Unfortunately dumping more $ into a new cam/install is not something I can do right now, this is NOT my daily driver, just a toy to play around with so I am not worried about the 'bucking' around town, that's something I am use to from my previous cammed C5's, this cam loves higher RPM's and that solves most 'bucking' issues while driving. I am more worried about when I come to a stop how the car bogs/surges down and almost stalls out, that's my biggest concern at this time.
Last edited by SmittyChevy; 08-26-2013 at 11:35 AM.
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uundeadarmyy (10-18-2020)
08-26-2013, 12:46 PM
#4
Safety Car
Sounds like a junk tune. A vacuum leak between the MAF and throttle body can cause some funky stuff, but a vacuum leak behind the throttle body will usually make the idle hang, not surge.
09-05-2013, 10:43 PM
#6
Burning Brakes
Hitechtunin
Speak to Ed for so good help
did mine all the way overseas! in Cape Town via email as I have HPtuners to read, flash and write
edcmat-l1@msn.com
did mine all the way overseas! in Cape Town via email as I have HPtuners to read, flash and write
edcmat-l1@msn.com
09-13-2013, 09:35 PM
#7
Burning Brakes
I wonder if that cam has too much overlap??
09-19-2013, 12:31 PM
#9
Instructor
A tuner should be able to adjust this right out. When I got my car tuned after getting a blower and blower cam, the car was doing the same thing. I took it back to the tuner and he either added more gas or made it more lean, but whatever he did fixed the problem. It was a 10 minute fix.
If your problem is the same as mine, it should be an easy fix.
If your problem is the same as mine, it should be an easy fix.
09-19-2013, 01:08 PM
#10
Former Vendor
Member Since: Oct 2006
Location: Auburn/Dacula/Lawrenceville Georgia
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A proper MAF / VE calibration will do wonders for that car if it's never been done. Having a reputable tuner who knows how to properly calibrate the above items is the first step that needs to be taken. You can't create good driveability if the fueling is wacko.
However, everyone is overlooking another issue. Camshaft overlap. That cam has 16 degrees of overlap and it's on a 110 lobe separation. That is going to cause some annoyances in a 6.0L engine below 2K rpm's that may not all be smoothed out with a tune. Not so much idle, as a good tuner can get the idle stabilized. However, buck / surge while cruising at low rpm's will be inevitable to some degree due to mechanical properties such as vacuum (or lack thereof), valve timing events, etc. It's unfortunate, but vendor marketing on some of these camshafts always seems to leave out the side effects of what will happen when you install one in a stock cube engine with a stock gear.
If the tuning is wacked, a reputable tuner can do wonders for you. For the below 2K stuff, a set of 3.91's or 4.11's will help clear the rest of it up.
Good luck.
However, everyone is overlooking another issue. Camshaft overlap. That cam has 16 degrees of overlap and it's on a 110 lobe separation. That is going to cause some annoyances in a 6.0L engine below 2K rpm's that may not all be smoothed out with a tune. Not so much idle, as a good tuner can get the idle stabilized. However, buck / surge while cruising at low rpm's will be inevitable to some degree due to mechanical properties such as vacuum (or lack thereof), valve timing events, etc. It's unfortunate, but vendor marketing on some of these camshafts always seems to leave out the side effects of what will happen when you install one in a stock cube engine with a stock gear.
If the tuning is wacked, a reputable tuner can do wonders for you. For the below 2K stuff, a set of 3.91's or 4.11's will help clear the rest of it up.
Good luck.
09-21-2013, 08:30 PM
#11
Former Vendor
A proper MAF / VE calibration will do wonders for that car if it's never been done. Having a reputable tuner who knows how to properly calibrate the above items is the first step that needs to be taken. You can't create good driveability if the fueling is wacko.
However, everyone is overlooking another issue. Camshaft overlap. That cam has 16 degrees of overlap and it's on a 110 lobe separation. That is going to cause some annoyances in a 6.0L engine below 2K rpm's that may not all be smoothed out with a tune. Not so much idle, as a good tuner can get the idle stabilized. However, buck / surge while cruising at low rpm's will be inevitable to some degree due to mechanical properties such as vacuum (or lack thereof), valve timing events, etc. It's unfortunate, but vendor marketing on some of these camshafts always seems to leave out the side effects of what will happen when you install one in a stock cube engine with a stock gear.
If the tuning is wacked, a reputable tuner can do wonders for you. For the below 2K stuff, a set of 3.91's or 4.11's will help clear the rest of it up.
Good luck.
However, everyone is overlooking another issue. Camshaft overlap. That cam has 16 degrees of overlap and it's on a 110 lobe separation. That is going to cause some annoyances in a 6.0L engine below 2K rpm's that may not all be smoothed out with a tune. Not so much idle, as a good tuner can get the idle stabilized. However, buck / surge while cruising at low rpm's will be inevitable to some degree due to mechanical properties such as vacuum (or lack thereof), valve timing events, etc. It's unfortunate, but vendor marketing on some of these camshafts always seems to leave out the side effects of what will happen when you install one in a stock cube engine with a stock gear.
If the tuning is wacked, a reputable tuner can do wonders for you. For the below 2K stuff, a set of 3.91's or 4.11's will help clear the rest of it up.
Good luck.
..... nailed it
08-23-2014, 10:09 PM
#12
1st Gear
Member Since: Jan 2013
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[QUOTE=SmittyChevy;1584762894]Hello all!
This is my first c6 corvette, coming from 2 other cammed C5's, I've never had this problem before and wondering if anyone has a solution or some information for me.
I just picked the car up last week, the previous owner gave me a short list of everything done to the car and I was told the performance parts were professionally installed and it was professionally tuned at IndyHP in Indianapolis. It is a 2005 LS2 car, the pars are: LG long tubes, no cats, X pipe, GLH catback, Vararam Intake, a 233/239 Cam (full specs on the cam are; 233/239 610/615 on a 110+3) and an AEM A/F meter (along with other suspension/cosmetic stuff).
My issue is a surge in idle at various times while diving the car as well as start up, again I've owned 2 previous cammed C5's and never ever had an issue with idle at any time so I don't have a clue as to whats going on. When I start this car (cold or hot) it cranks over, then feels like it wants to stall out right away but then goes into a nice lope around 800-900rpm just like it should. When I am driving, pretty much anytime I put the car into neutral (either from decelerating or just throwing it into N), it will surge down as low as 100-200RPM (mostly surges down to about 400, but will bounce back and forth between 400-1000 a few times before going back up and loping around 900RPM. I can sometimes help it by blipping the gas pedal when the RPMs dip down low where I think its going to stall out. It mostly happens when I come to a stop sign or red light, or in stop and go traffic, or if I am still moving but put the car into neutral, pretty much every time. Its annoying and hope there is a way to solve it. Another observation I've noticed is my oil pressure dips down when the idle surges, but I assume its normal behavior for the oil press to follow the RPMs like that.
I am calling around today to some local (and non-local) shops to see about getting the car re-tuned, although I am not sure this will solve my problem I still want to re-tune it so I know it has a safe and sound tune on it.
I drove the car 400miles home the day I bought it, and had 0 issues other than the idle surge. Yesterday I saw a CEL come up so I took it to my uncle's garage to scan it an it said something along the lines of: "bank 1 lean"
But I have YET to go WOT with the car since I have no proof the car was tuned right and honestly I do not know how to read this A/F gauge, I assume its to stay in the rich (green) when at WOT, but I am not doing that without a proper dyno tune - i'd rather be safe than sorry, i've heard of too many horror stories.
Let me know if anyone has any input to what my problem could be and if a proper tune will solve it or is this just the way some cam's are?
I can make a video of what it does to show you guys if that will help.
Thanks in advance!
edit: Does this sound like it could be a vacuum leak issue at all? I was speaking to one of the Tech's at my uncle's shop and he said it could be a vacuum leak causing the idle surge and CEL.
Did you by chance figure out what was wrong? I have a 07 ls2 with an MS3 cam 237/242 .603"/.609" 112+ 2 and it's doing the exact same thing. I do the same thing by bleeping the throttle to keep it from surging at stop lights.
This is my first c6 corvette, coming from 2 other cammed C5's, I've never had this problem before and wondering if anyone has a solution or some information for me.
I just picked the car up last week, the previous owner gave me a short list of everything done to the car and I was told the performance parts were professionally installed and it was professionally tuned at IndyHP in Indianapolis. It is a 2005 LS2 car, the pars are: LG long tubes, no cats, X pipe, GLH catback, Vararam Intake, a 233/239 Cam (full specs on the cam are; 233/239 610/615 on a 110+3) and an AEM A/F meter (along with other suspension/cosmetic stuff).
My issue is a surge in idle at various times while diving the car as well as start up, again I've owned 2 previous cammed C5's and never ever had an issue with idle at any time so I don't have a clue as to whats going on. When I start this car (cold or hot) it cranks over, then feels like it wants to stall out right away but then goes into a nice lope around 800-900rpm just like it should. When I am driving, pretty much anytime I put the car into neutral (either from decelerating or just throwing it into N), it will surge down as low as 100-200RPM (mostly surges down to about 400, but will bounce back and forth between 400-1000 a few times before going back up and loping around 900RPM. I can sometimes help it by blipping the gas pedal when the RPMs dip down low where I think its going to stall out. It mostly happens when I come to a stop sign or red light, or in stop and go traffic, or if I am still moving but put the car into neutral, pretty much every time. Its annoying and hope there is a way to solve it. Another observation I've noticed is my oil pressure dips down when the idle surges, but I assume its normal behavior for the oil press to follow the RPMs like that.
I am calling around today to some local (and non-local) shops to see about getting the car re-tuned, although I am not sure this will solve my problem I still want to re-tune it so I know it has a safe and sound tune on it.
I drove the car 400miles home the day I bought it, and had 0 issues other than the idle surge. Yesterday I saw a CEL come up so I took it to my uncle's garage to scan it an it said something along the lines of: "bank 1 lean"
But I have YET to go WOT with the car since I have no proof the car was tuned right and honestly I do not know how to read this A/F gauge, I assume its to stay in the rich (green) when at WOT, but I am not doing that without a proper dyno tune - i'd rather be safe than sorry, i've heard of too many horror stories.
Let me know if anyone has any input to what my problem could be and if a proper tune will solve it or is this just the way some cam's are?
I can make a video of what it does to show you guys if that will help.
Thanks in advance!
edit: Does this sound like it could be a vacuum leak issue at all? I was speaking to one of the Tech's at my uncle's shop and he said it could be a vacuum leak causing the idle surge and CEL.
Did you by chance figure out what was wrong? I have a 07 ls2 with an MS3 cam 237/242 .603"/.609" 112+ 2 and it's doing the exact same thing. I do the same thing by bleeping the throttle to keep it from surging at stop lights.
