LS1 IAC valve and High Idle

Reply Subscribe

Thread Tools

Search this Thread

Jan 10, 2014 | 09:39 AM

MadFirehawk86

Thread Starter

On The Tree

iTrader: (2)

Joined: Dec 2013

Posts: 143

Likes: 0

From: Texas

LS1 IAC valve and High Idle

Ok, I am having a problem with my idle. When warm the car holds steady at 1000-1100 rpm. I started investigating and found that the pintle on the IAC was missing so I replaced the IAC with another one.

After I replaced the IAC the idle was still the same so I removed the IAC and turned the ignition on to see if it moved...didnt move, proceeded to start...still didnt move. I dont believe the IAC is bad, but who knows. Is there a way to test the IAC? Is there a procedure that needs to be done when installing a new IAC?? I would think that it would still move even if I didnt..

The car has AIR and EGR delete with longtubes and I dont believe the ECM was tuned for the deletes...could this be the issue? Any help is greatly appreciated. The car is a 98 Formula.

Jan 10, 2014 | 10:12 AM

demonspeed

It's not mine! woo hoo!

iTrader: (7)

Joined: Jun 2003

Posts: 7,128

Likes: 5

From: Pittsburgh, PA

Sounds like a problem I had... ended up being a cracked PCV hose. Just check your PCV system for any vacuum leaks and see if that helps. Might be a good excuse to do the '04 LS6 PCV system

Jan 10, 2014 | 11:10 AM

MadFirehawk86

Thread Starter

On The Tree

iTrader: (2)

Joined: Dec 2013

Posts: 143

Likes: 0

From: Texas

Ok so I temporarily blocked off the pcv system at the manifold and no change. I'm not getting any movement out of the iac valve when it's not attached to the manifold. I wish I had a scan tool or something to see exactly what's going on.

Jan 10, 2014 | 12:18 PM

demonspeed

It's not mine! woo hoo!

iTrader: (7)

Joined: Jun 2003

Posts: 7,128

Likes: 5

From: Pittsburgh, PA

Did this start happening right after you did the LT's and deleted emissions?

Jan 10, 2014 | 12:41 PM

MadFirehawk86

Thread Starter

On The Tree

iTrader: (2)

Joined: Dec 2013

Posts: 143

Likes: 0

From: Texas

Quote:

Originally Posted by demonspeed

Did this start happening right after you did the LT's and deleted emissions?

Problem is, I dont know... I purchased it this way. It has o2 sims for the rear o2 sensor with true duals and x pipe dumped before the axle as well.

Its foolish to speak this way, but at this point I wouldnt mind going back completely stock..stock manifolds, stock y pipe, egr and air installed. I just want a vehicle that functions as it should. Personally I dont see the point of deleting the EGR the gain is very minute, if any, and is mainly for aeshetics...to me thats not worth it if the vehicle isnt going to idle right.

Jan 10, 2014 | 02:52 PM

MadFirehawk86

Thread Starter

On The Tree

iTrader: (2)

Joined: Dec 2013

Posts: 143

Likes: 0

From: Texas

80 views and nothing to add? Come on guys Im sure some of you have had these issues before. Please help out a fellow F body owner.

Jan 10, 2014 | 05:54 PM

demonspeed

It's not mine! woo hoo!

iTrader: (7)

Joined: Jun 2003

Posts: 7,128

Likes: 5

From: Pittsburgh, PA

I think you'd be happy with the mods if you weren't chasing the problem. I personally like the car being emissions-free simply because it makes it easier to work on without all those stupid hoses everywhere!

I'll move this down to the Gen III External Engine section in hopes for some more ideas...