I have an S2, here's my problem (Shaner is awesome with his customer service, he's trying to fix my problem too, I just figured I give you guys a try) When in neutral (A4)
my rpms are about 700-750,no surging, when I put it in drive the rpm's shoot to 1000 then to about 750 then surges slowly between the two.And when driving and coming to a stop the rpm's stop at about 1100-1200 then slowly goes to about 750 or so then surges a little.I have the TB bypass if that matters, the bolts are tight, all connections are secure, everything is hooked up right. What's the problem? Also this is my second S2, Shaner thought it could have been bad or bad electronics so he sent me a new S2.Help me out guys!!

Thanks, Jay

 

If 2 S2's did the same thing, I don't think it's the porting.

Did you use the same IAC on both TB's? It could be that.

Did you do an "Idle Relearn"? Did anything change after that?

I'm probably reiterating what Shaner said. Work with him.

 

I did the idle re-learn ( unplugged the battery for 40 minutes, helped a little )
I changed the top sensor on the T.B ( don't know which one that is, helped a little )
Shaner is going to send me a new sensor for the bottom, he also told me to try the idle re-learn again.Again, Shaner has EXCELLENT customer service.

Any other suggestions?

 

Could it be my Z just doesn't like ported T.B.?

 

Try spraying some WD-40 or carb cleaner around the TB/manifold connection with the car running to try to identify a vacuum leak. Make sure your all vacuum related hoses are secured. As stated above, do the idle relearn and drive it around to make sure you have the car up to temp and then do the idle relearn again. The car will still need to learn some after that , but your idle should be stable at this point. Keep us posted on the results and symptoms if it does not clear up. We can get this figured out. Mark is an awesome guy to deal with. He definitely puts out quality work and service.Take care.


James

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TXCAMSS:
<strong> Try spraying some WD-40 or carb cleaner around the TB/manifold connection with the car running to try to identify a vacuum leak. Make sure your all vacuum related hoses are secured. As stated above, do the idle relearn and drive it around to make sure you have the car up to temp and then do the idle relearn again. The car will still need to learn some after that , but your idle should be stable at this point. Keep us posted on the results and symptoms if it does not clear up. We can get this figured out. Mark is an awesome guy to deal with. He definitely puts out quality work and service.Take care.


James </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks,I'll try the WD-40 and the idle re-learn again. Hopefully tomorrow, if their's no snow.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by N.Y. LS1:
<strong> I did the idle re-learn ( unplugged the battery for 40 minutes, helped a little )
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">There is a whole lot more to the idle re-learn procedure than unplugging the battery. There is a procudure somewhere on this site or LS1.com. It takes about 15-20 minutes to do. You will have it in different gears for specified amounts of time. I had to do it on my car and the idle on my car has been perfect ever since.

 

PCM Idle Learn Procedure

Disconnect battery (or at least the batt power to PCM)

Automatic Transmission

1. Turn OFF the ignition
2. Restore battery power
3. Turn OFF the A/C controls
4. Set the parking brake and block the drive wheels.
5. Start the engine
6. Ensure the engine coolant temp is more than 80*C (176*F)
7. Shift the transmission into Drive
8. Allow the engine to idle for 5 minutes
9. Shift the transmission into Park
10. Allow the engine to idle for 5 minutes
11. Turn OFF the engine for 30 seconds

Manual Transmission

1. Turn OFF the ignition
2. Restore battery power
3. Turn OFF the A/C controls
4. Set the parking brake and block the drive wheels.
5. Place the transmission in Neutral
6. Start the engine
7. Ensure the engine coolant temp is more than 80*C (176*F)
8. Allow the engine to idle for 5 minutes
9. Turn OFF the engine for 30 seconds

 

I have heard that alot of the pre-2000 Ls1's have this problem with the Ported TB's.

 

Update:

I did the idle re-learn ( the way OLD SStroker said ), I then drove the car , no noticable change. I then sprayed WD-40 at the TB and manifold , no change. I triple checked all connections, everything is good.When in Park or neutral their is no surging, it's when put in gear the idle surges. What's next??Could my tourqe converter cause the surging?
Maybe when I change the bottom sensor the surging will stop. Should I live with it? I have a 224-224-114 cam, LS6 intake, ASP crank pulley and new plugs and wires going on Monday, will these make the problem worse? Any help is appreciated!!!

Jay

ps- how much are new IAC and TPS from GM or any other place?Expensive?

<small>[ February 15, 2003, 10:16 AM: Message edited by: N.Y. LS1 ]</small>

 

I am so glad the correct idle relearn was posted. That makes all the difference in the world. OK , I didn't realize you had a cam. If you haven't adjusted the throttle screw then you can likely tune out the surging easily by turning the throttle adjustment screw (Torx head)out so it will in crease the throttle position. It is real sensitive to adjustments so I would go a little at a time. I would pull the TB off and reinstall the adjustment screw form the top so it can be adjusted easily. My stock TB was tough to get tuned after the cam install , but the Shaner needed very little attention. It could be that it just needs a bit of adjustment. Alot of people talk in detail about fine tuning the IACs to a magic number, but mine have been at zero from day one and I could not ask for a better quality idle. I have a few questions.

Do you have custom tuning?
If so what is your idle programed at?
Did your car idle good with this cam and the stock TB?

There are some other adjustable idle related tables to help, but they may not be needed.

I would adjust the screw out to get the idle up where it is slow to idle down and "slowly" go back down with the adjustment screw until the surging stays away and the idle is low enough to stay stable. This is kind of a half as way to get you close to where you need to be.

If you have LS1edit or tuning access, I would raise the idle set point to 850/925 rpm and raise the base timing to 26-28 degrees. After that you can change the "AIT in park" and "AIT in gear" temperature tables if needed. You should not have to "live with it".

Remember to may small adjustments and then drive the car to let it learn. Also make sure the car is up to temp when any adjsutments are made. Good luck!!


James

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TXCAMSS:
<strong> I am so glad the correct idle relearn was posted. That makes all the difference in the world. OK , I didn't realize you had a cam. If you haven't adjusted the throttle screw then you can likely tune out the surging easily by turning the throttle adjustment screw (Torx head)out so it will in crease the throttle position. It is real sensitive to adjustments so I would go a little at a time. I would pull the TB off and reinstall the adjustment screw form the top so it can be adjusted easily. My stock TB was tough to get tuned after the cam install , but the Shaner needed very little attention. It could be that it just needs a bit of adjustment. Alot of people talk in detail about fine tuning the IACs to a magic number, but mine have been at zero from day one and I could not ask for a better quality idle. I have a few questions.

Do you have custom tuning?
If so what is your idle programed at?
Did your car idle good with this cam and the stock TB?

There are some other adjustable idle related tables to help, but they may not be needed.

I would adjust the screw out to get the idle up where it is slow to idle down and "slowly" go back down with the adjustment screw until the surging stays away and the idle is low enough to stay stable. This is kind of a half as way to get you close to where you need to be.

If you have LS1edit or tuning access, I would raise the idle set point to 850/925 rpm and raise the base timing to 26-28 degrees. After that you can change the "AIT in park" and "AIT in gear" temperature tables if needed. You should not have to "live with it".

Remember to may small adjustments and then drive the car to let it learn. Also make sure the car is up to temp when any adjsutments are made. Good luck!!


James </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">First off, thank you for your help.
I should have made it clearer, I have the stock cam, new cam and everything else is going in Monday (2-17-03). Also custom tuning is being done, can this help my surging. I'm afraid the idle will be much worse after the cam and stuff goes in, if so, I think I'll call Shaner to see if I should try a stock TB. This is of course after I try all the stuff you told me.

Anything else I should try while the stock cam is in?

Thanks again, Jay

 

You asked about the torque converter... did you change it recently?
just FYI yes if you're low on tranny fluid the torque converter CAN give you a rougher idle.
I kinda doubt this is the case here.
Just guessing I'd check the adjustment of the throttle position sensor. The minimum air rate adjustment screw could actually fix the problem if it's the TPS out of adjustment. The TPS could have been damaged by vibration or water & may need replaced.
If you've replaced the IAC already and inspected the area where the plunger fits, then it seems unlikely to be the fault.

oh yeah I'm looking to by a stock or damaged throttlebody if you have one <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> email please

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by white2001s10:
<strong> You asked about the torque converter... did you change it recently?
just FYI yes if you're low on tranny fluid the torque converter CAN give you a rougher idle.
I kinda doubt this is the case here.
Just guessing I'd check the adjustment of the throttle position sensor. The minimum air rate adjustment screw could actually fix the problem if it's the TPS out of adjustment. The TPS could have been damaged by vibration or water & may need replaced.
If you've replaced the IAC already and inspected the area where the plunger fits, then it seems unlikely to be the fault.

oh yeah I'm looking to by a stock or damaged throttlebody if you have one <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> email please </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have a pro-tourqe 2800 stall converter, it was in the car before I bought the ported TB.Never had the idle problem with the stock TB and 2800 converter.
I think I'm going to try cleaning the IAC with some TB cleaner.

 

This is a IAC motor problem, that's why early f-body LS1's do this, they have the easy IAC motor. You need to go pick up a new (2002) IAC motor for your car, it should fix the problem.

Shaner should send the idle relearn with the TB, it's one way to fix easy idle problems fast.

Bret

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by SStrokerAce:
<strong> This is a IAC motor problem, that's why early f-body LS1's do this, they have the easy IAC motor. You need to go pick up a new (2002) IAC motor for your car, it should fix the problem.

Shaner should send the idle relearn with the TB, it's one way to fix easy idle problems fast.

Bret </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Can you tell me how much a new IAC is and where to buy it from?Part #?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by N.Y. LS1:
<strong>Can you tell me how much a new IAC is and where to buy it from?Part #? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Try your friendly(?) local GM dealer. Just tell them exactly what car it's for.

 

Having had 5 cams over the last five years I am the king of dealing with surging.

Try parts@sdpc2000.com and see how much they will charge for an IAC motor.

Surging at idle might be fixed by:
-cracking the TB blade
-OR drilling out the idle air hole
-OR leaning at the base with MAF T
-OR adding more base timing

You are trying to address what can be an overrich condition. Either add more air or take out fuel.

Ported TB's don't cause the problem unless the blade is not sealing, and too much air is getting past it. Or the IAC setup has been damaged. Or the hole where the IAC air goes has been made too small.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Old SStroker:
[[/qb]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Try your friendly(?) local GM dealer. Just tell them exactly what car it's for. [/QB][/QUOTE]


Even though I have a 98, I should buy the 02 IAC like you said, correct?Thanks for all your help

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by SStrokerAce:
<strong> You need to go pick up a new (2002) IAC motor for your car.........</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">yep,

If that doesn't work the TB is not sealing like PSJ said.

Bret