To the 4.2 crew
Postmaster
Joined: Aug 2001
Posts: 4,532
Likes: 5
From: Trussville, Alabama
I am guessing you are asking about the
Intake Manifold Runner Control (IMRC)
It was a setup used in the early 2000s.
The intake manifold had a long runner and a short runner. A vacuum line attached to a vacuum solenoid switched between the short runner and the long runner based on engine RPM. I seem to remember the switch occurred around 4500 rpm.
Also, I think a change was made to an electric solenoid after a few years of a vacuum solenoid setup.
All the hardware was located on the back (firewall) side of the intake manifold.
Intake Manifold Runner Control (IMRC)
It was a setup used in the early 2000s.
The intake manifold had a long runner and a short runner. A vacuum line attached to a vacuum solenoid switched between the short runner and the long runner based on engine RPM. I seem to remember the switch occurred around 4500 rpm.
Also, I think a change was made to an electric solenoid after a few years of a vacuum solenoid setup.
All the hardware was located on the back (firewall) side of the intake manifold.
Elder User
Joined: Jan 2008
Posts: 973
Likes: 0
From: Gatineau, Quebec
My 99 has the electronic control...
Having said that....
The control is on the backside of the engine below the upper intake as stated.
It is nearly impossible to do anything to the control or linkage rods without taking off the upper intake.
Having said that....
The control is on the backside of the engine below the upper intake as stated.
It is nearly impossible to do anything to the control or linkage rods without taking off the upper intake.
Postmaster
Joined: Aug 2001
Posts: 4,532
Likes: 5
From: Trussville, Alabama
Thanks. I guess I had it backwards. Electric first then vacuum.
Also, I noticed a typo in my reply. I think the switch in runners occurred around 2500 rpm. Not 4500.
Just didn't pay attention when I was typing the other post.
Also, I noticed a typo in my reply. I think the switch in runners occurred around 2500 rpm. Not 4500.
Just didn't pay attention when I was typing the other post.
Elder User
Joined: Jan 2008
Posts: 973
Likes: 0
From: Gatineau, Quebec
I could be wrong Brian, but I think you had it right the first time. The Vacuum control was replaced by the electronic control....I was implying that I think they changed over in 99
Can't remember at what rpm's they open though.
Can't remember at what rpm's they open though.
Thread
Thread Starter
Forum
Replies
Last Post
JByrd1173
Y-Block V8 (239, 272, 292, 312, 317, 341, 368)
3
Dec 11, 2004 03:35 AM
