CEL problems W/ new 70mm TB and Ported plenum
10-02-2009, 09:22 PM
#1
Thread Starter
Join Date: Feb 2006
Location: Nashville, TN
Posts: 41
CEL problems W/ new 70mm TB and Ported plenum
Ok here goes, Bought a new 70 mm TB and ported /polished upper plenum for my 03 GT.
After reconnecting the battery it started up fine, but idled at bout 1400 RPM's.
After doing some research on the forum for a solution, it seems this is a frequent problem.
So I decided to follow the advice from several threads on the problem and use a smaller
restricter on the IAC. I started at the OEM size hole and worked my way down by 16ths
until the RPM's dropped to about 950-1000. A little high but I can live with it, tried adjusting the throttle stop to get it lower with no results.
Problem is now I get a CEL that reads problem with the IAC. Will this affect it passing emissions testing? How can I get rid of the CEL? Im at a loss for what to do now and
considering putting the stock setup back on and just callin it a dy! Any know what to do?
After reconnecting the battery it started up fine, but idled at bout 1400 RPM's.
After doing some research on the forum for a solution, it seems this is a frequent problem.
So I decided to follow the advice from several threads on the problem and use a smaller
restricter on the IAC. I started at the OEM size hole and worked my way down by 16ths
until the RPM's dropped to about 950-1000. A little high but I can live with it, tried adjusting the throttle stop to get it lower with no results.
Problem is now I get a CEL that reads problem with the IAC. Will this affect it passing emissions testing? How can I get rid of the CEL? Im at a loss for what to do now and
considering putting the stock setup back on and just callin it a dy! Any know what to do?
10-03-2009, 07:41 AM
#2
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
It sounds as though the the throttle stop screw is improperly set, here is the procedure for doing so...
10-03-2009, 05:21 PM
#3
Thread Starter
Join Date: Feb 2006
Location: Nashville, TN
Posts: 41
Ok Cliffy, I understand what your saying but I dont understand one thing.
If there is a .010 gap at the throttle stop and its still idling too high, then
how is increasing the gap gonna bring down the RPM's? the throttle position is already closed as far as its going to go. Or is there something I dont understand?
If so then please teach this unworthy grasshopper! ;-)
If there is a .010 gap at the throttle stop and its still idling too high, then
how is increasing the gap gonna bring down the RPM's? the throttle position is already closed as far as its going to go. Or is there something I dont understand?
If so then please teach this unworthy grasshopper! ;-)
10-03-2009, 06:08 PM
#4
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
Ok Cliffy, I understand what your saying but I dont understand one thing.
If there is a .010 gap at the throttle stop and its still idling too high, then
how is increasing the gap gonna bring down the RPM's? the throttle position is already closed as far as its going to go. Or is there something I dont understand?
If so then please teach this unworthy grasshopper! ;-)
If there is a .010 gap at the throttle stop and its still idling too high, then
how is increasing the gap gonna bring down the RPM's? the throttle position is already closed as far as its going to go. Or is there something I dont understand?
If so then please teach this unworthy grasshopper! ;-)
If so,
- are you certain the throttle cable is not binding, or too tight, and not letting the plate close--try forcing the plate closed manually and see if the idle drops?
- Is the throttle plate misaligned in the TB bore, and not closing properly?
- Are there any intake/vacuum leaks after the MAF, in the intake tract or the plenum?
- Did you disconnect the battery for 5-7 minutes to clear the KAM?
10-03-2009, 08:01 PM
#5
Thread Starter
Join Date: Feb 2006
Location: Nashville, TN
Posts: 41
Yes the gap is set at .010 and idle is still 1000 RPM's.
I tried manually closing it more, its at an end, it wont budge.
Checked for leakes between MAF and plenum, no leakes there.
Disconnected the battery for 10 Mins.
Not sure of misalignment of throttle plate, but when the throttle
closes you can hear a definite metal on metal sound like its hitting a
stop but not on the throttle stop screw. How can I even tell if the
throttle plate is misaligned? The Iac was working just fine before the
TB install.
I tried manually closing it more, its at an end, it wont budge.
Checked for leakes between MAF and plenum, no leakes there.
Disconnected the battery for 10 Mins.
Not sure of misalignment of throttle plate, but when the throttle
closes you can hear a definite metal on metal sound like its hitting a
stop but not on the throttle stop screw. How can I even tell if the
throttle plate is misaligned? The Iac was working just fine before the
TB install.
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