GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

IAC Problem Need Dynamite!

Thread Tools
 
Search this Thread
 
Old Nov 16, 2008 | 08:47 PM
  #1  
M.Roberts's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: Mar 2003
Posts: 402
Likes: 0
From: Turkey Creek, LA
Default IAC Problem Need Dynamite!

Does anyone know, if it were possible, to put a resistor inline to the IAC motor wiring? Or some way to physically de-sensitize it? There are 4 wires going to it, not much info in Chiltons book. My truck surges awful between 45-55 mph, done it since the cam swap, few years ago. When I unplug the IAC, it runs great at speed, just idles poorly. Why does the IAC even cycle when I'm driving it on the road? I had this thing tuned at MTI in Houston, too. THIS is driving me nuts!
Reply
Old Nov 16, 2008 | 08:57 PM
  #2  
dirt track racer 81's Avatar
TECH Senior Member
iTrader: (45)
 
Joined: Jun 2005
Posts: 9,439
Likes: 13
From: Hennessey, Oklahoma
Default

DozerDan can get you some dynomite
Reply
Old Nov 16, 2008 | 09:51 PM
  #3  
budhayes3's Avatar
PT's Slowest Truck
iTrader: (19)
 
Joined: Apr 2004
Posts: 17,863
Likes: 2
From: Hackensack, NJ
Default

Don't hack up the wiring and try to desensitize the IAC, there's something in the tuning that needs to be ironed out...
Reply
Old Nov 16, 2008 | 09:57 PM
  #4  
1FastBrick's Avatar
Custm2500's Rude Friend
15 Year Member
Loved
Liked
Community Favorite
iTrader: (17)
 
Joined: Apr 2007
Posts: 14,580
Likes: 891
From: JunkYard
Default

I would also say it's most likely something overlooked in the tune. Unless the IAC motor is bad???
Reply
Old Nov 16, 2008 | 10:15 PM
  #5  
M.Roberts's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: Mar 2003
Posts: 402
Likes: 0
From: Turkey Creek, LA
Default

well, I swapped it out a couple of times, and its always the same. Checked and cleaned it more than once to be sure. IF it almost does perfect with it unplugged, I figured if I could calm it down somehow by altering the amount of voltage it gets I might could smooth it out where I could live with it. I run a predator custom tune on it now not much I can do with it. Just trying to find an economical solution.

Thanks for the help

How much does Dozer Dan charge for a stick?
Reply
Old Nov 16, 2008 | 10:25 PM
  #6  
dirt track racer 81's Avatar
TECH Senior Member
iTrader: (45)
 
Joined: Jun 2005
Posts: 9,439
Likes: 13
From: Hennessey, Oklahoma
Default

its more than likely in the tune. have you logged the iac to see if its jumping around alot? something you see in bigger cams is a lean surge that can cause bucking at light throttle loads, but just since you have a small cam i wouldnt rule that out because it could be a tune problem
Reply
Old Nov 16, 2008 | 10:30 PM
  #7  
M.Roberts's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: Mar 2003
Posts: 402
Likes: 0
From: Turkey Creek, LA
Default

I dont have anything to monitor the program with to know what its doing. I wish I did.
Reply
Old Nov 16, 2008 | 10:42 PM
  #8  
dewmanshu's Avatar
Moderately Differentiated
20 Year Member
Liked
iTrader: (4)
 
Joined: Nov 2004
Posts: 27,563
Likes: 3
From: Maryland
Default

I can't imagine that 206/212 cam causing too many issues. What's the LSA on it? Unfortunately, having the predator, you are kind of held hostage. The tune needs to be adjusted. Running a resistor in theory would work to some degree today. Maybe not in the spring time or summer, but your idea on the surface makes sense to me. If you have no economical way to adjust the tune, PM Torque_Wrench and ask him what wires do what on the IAC (tell him dewmanshu said he said he would give that info up). Which ever the one is the control voltage, fug it, buy a bag of resistors at Radio Shack and start experimenting.
Reply
Old Nov 17, 2008 | 10:25 PM
  #9  
M.Roberts's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: Mar 2003
Posts: 402
Likes: 0
From: Turkey Creek, LA
Default

EVERYONE thanks for the input

Dewmanshu, I pm'd Torque_Wrench to see if he'd know, and if I can decipher the wiring, Im gonna go for it... Even thought about a rheostat mounted somewhere inside the cab, or a switch, some way to disable the IAC when I am driving like on longer trips, and turn it back on when I need it. Hmmm I think the cam is 112??? lsa , not sure its been a while.
Reply
Old Nov 23, 2008 | 02:33 PM
  #10  
M.Roberts's Avatar
Thread Starter
TECH Regular
iTrader: (4)
 
Joined: Mar 2003
Posts: 402
Likes: 0
From: Turkey Creek, LA
Default

Surely somebody knows about this???
Reply



All times are GMT -5. The time now is 07:22 AM.