SPI intake assembly - Ford Focus Forum, Ford Focus ST Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Ford Focus Forum, Ford Focus ST Forum > Ford Focus Tech Discussions > General Technical Chat

General Technical Chat This section is for technical discussions relating to general maintenance, electrical issues, engine trouble, and recalls.

Search This Forum | Image Search | Advanced Search    
Ford Focus Tire & Wheels FocusFanatics Merchandise

Reply
 
Thread Tools Display Modes
Old 07-10-2013, 07:05 PM   #1
p58ff
Focus Enthusiast
 
p58ff's Avatar
 
Join Date: Jul 2005
Fan#: 25247
Location: VA, VA
What I Drive: 2010 Red 4-Door SES

Posts: 148
FF Reputation: 1 p58ff Good Standing Member
Buy-Sell-Trade Rating: (1)
SPI intake assembly

The intake manifold assembly as most of you know is composed of two parts, the intake manifiold and the split-port injection part. I cannot remember it's proper name right now...sorry about that.

On the second part there is a screw that looks to be used to adjust some setting. Can some one enlighten me as to what it sets in the scheme of things?

Is it an idle setting, some sort of mixture adjustment?

I ask since I just replaced the cylinder head, cleaned out everything, and now I find the car is not quite right at idle. I didn't adjust the screw, actually it's bent pretty badly so I couldn't adjust it if I wanted too. I don't think this is related to my problem but I'd still like to know what it is for.

Thanks.


p58ff is offline  
    Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 07-10-2013, 10:48 PM   #2
BC_ZX3
DTC P0606
 
BC_ZX3's Avatar
 
Join Date: Jul 2007
Fan#: 48751
Location: Vancouver, BC, Canada
What I Drive: 2001 Red ZX3 Turbo

Posts: 2,938
Points 2,053, Level 27
Points: 2,053, Level: 27 Points: 2,053, Level: 27 Points: 2,053, Level: 27
Level Up 36% Completed
Level up: 36% Level up: 36% Level up: 36%
Forum Activity 5%
Activity: 5% Activity: 5% Activity: 5%
FF Reputation: 88 BC_ZX3 Excellent Standing Member
Buy-Sell-Trade Rating: (3)
Quote:
Originally Posted by p58ff View Post
I cannot remember it's proper name right now...sorry about that.
Throttle body.

Quote:
Originally Posted by p58ff View Post
Is it an idle setting, some sort of mixture adjustment?
Neither. It is simply a non-adjustable mechanical stop for the throttle plate movement. It does not control idle speed directly. Your car is fuel injected, not carbureted, so old school idle speed screws, idle speed jets and float bowl levels don't apply. If you do manage to move it (usually after removing a factory installed anti-tanper device), the PCM will simply compensate for any small changes you've made.

The PCM controls the idle speed via the Idle Air Control Valve (IACV) using various engine sensors. Think of the IACV as a variable sized bypass hole or small passageway around the closed throttle plate. Modern engines use an IACV because idle speed is more accurately controlled by the PCM under a wide range of operating condition than it would be by an old style "fixed" - albeit manually adjustable - idle screw.

The Ford, or any modern system, relies on the throttle body and intake system being "air tight" for the system to work correctly - only air that passes the MAF (Mass Air Flow) sensor is used (metered air) for idle speed calculations by the PCM. Therefore, if you've had the thing to pieces and your idle is not inconsistent and low, you likely have a vacuum leak due to a loose fastener, loose clamp or perhaps a leaking or perished gasket somewhere after the MAF.
BC_ZX3 is offline  
    Reply With Quote Quick reply to this message
Reply

Bookmarks & Social Networks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Focus Forum, Ford Focus ST Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 03:09 AM.


Copyright 2002-2014 FocusFanatics.com. All Rights Reserved : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Cadillac ATS-V, Ford Fusion and Acura TLX. You can find all Ford Focus and Focus ST related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area.