Rough Idling, Low RPMS - TCCoA Forums
 
LinkBack Thread Tools
post #1 of 12 (permalink) Old 01-23-2005, 07:44 PM Thread Starter
 
Join Date: Jan 2005
Posts: 755
Rough Idling, Low RPMS

Today, when I started my car, it started, then immeduiatly dropped to 500 RPMs, and was struggling to keep running. It was fine after I shifted it into drive. I was in there with it idling before for 30 minutes, and it was fine. I then went to eat, and ten minutes later, it does that. Itss done it a couple times before. Whats the problem?
NiteFire is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 01-23-2005, 08:46 PM
Trumpeter Extraordinaire
 
IronChopz's Avatar
 
Join Date: Jul 2002
Location: Saturn (or SE Michigan)
Age: 57
Posts: 2,916
Could be a dirty/faulty Mass Air Flow sensor, or a dirty/faulty Idle Air Control valve...

Start off by cleaning the MAF sensor (check the Technical Articles under Intake), and see if that helps any. I usually reset the PCM after cleaning the sensor, then I drive the car at 50-65mph for about 10 miles.

Try a search here on rough idle, and see what's been posted.
IronChopz is offline  
post #3 of 12 (permalink) Old 01-24-2005, 11:45 PM
 
Join Date: Sep 2003
Posts: 882
My car just started the same ****, the IAC looks new, the prev owner said it did this, and I had no prob for the first 2 or 3 months I owned it, until yesterday.

I am going to see what the tech article says about cleaning the maf.

I did drive the car home w/o an air filter, man, the 3.8 NA ia friggin' slow, I came off of an SC to this, arg! lol...
sc0tty8 is offline  
Sponsored Links
Advertisement
 
post #4 of 12 (permalink) Old 01-25-2005, 07:59 AM
Seasoned PostWhore
 
bowez's Avatar
 
Join Date: Aug 2002
Location: NEAR
Posts: 2,472
How old and type of Plugs?
bowez is offline  
post #5 of 12 (permalink) Old 01-25-2005, 11:48 AM
Moderator
Iowa Chapter Director
Uber Luber
TCCoAAC Member
Moderator
 
Thomas's Avatar
 
Join Date: Jul 2002
Location: Ames, Iowa
Age: 35
Posts: 8,978
it wouldnt be the MAF because for the first 30 seconds of startup the car is in open loop running on a preset program from the eec. The IAC should be the culpirit since that starts working right after startup to let the car idle.
-Thomas

1988 Notch Mustang: - 438W, direct port n2o, t56
2003 SVT Focus: - SCT X3 tuner
Thomas is offline  
post #6 of 12 (permalink) Old 01-25-2005, 11:51 AM
 
Join Date: Sep 2003
Posts: 882
Quote:
Originally Posted by Thomas
it wouldnt be the MAF because for the first 30 seconds of startup the car is in open loop running on a preset program from the eec. The IAC should be the culpirit since that starts working right after startup to let the car idle.
-Thomas

The idle kicks up high and then it tries to stall itself.

So clean the IAC then? How do I go about that?
sc0tty8 is offline  
post #7 of 12 (permalink) Old 01-25-2005, 11:54 AM
 
Join Date: Nov 2004
Posts: 598
It could also be an air leak somewhere in your intake tube between your MAFS and TB. I tried to rig one up one time and had a leak which caused it to idle rough and low and eventually cut off. Once I found the leak and tightened it up, it solved the problem. Of course, this would only really apply if you have rigged something else in place of the OEM one. This is just a possiblity, but like Thomas and IronChopz said, it's probably the IACV.
504 Bird is offline  
post #8 of 12 (permalink) Old 01-25-2005, 11:59 AM
 
Join Date: Sep 2003
Posts: 882
I have the stock tube right here on my kitchen counter, and I did check for cracks and such, the tube is still flexible.

I just need to know how to clean the IAC.
sc0tty8 is offline  
post #9 of 12 (permalink) Old 01-25-2005, 12:06 PM
 
Join Date: Nov 2004
Posts: 598
I have no idea how to clean it, I just ordered a new one from Dan yesterday. It was about $60 with gasket
504 Bird is offline  
post #10 of 12 (permalink) Old 01-25-2005, 12:58 PM
Moderator
Iowa Chapter Director
Uber Luber
TCCoAAC Member
Moderator
 
Thomas's Avatar
 
Join Date: Jul 2002
Location: Ames, Iowa
Age: 35
Posts: 8,978
the 3.8 IAC is a bit cheaper. I've actually got one right here if you want it. I upgraded to the 5.0 60mm tb and have that IAC. But try cleaning it first. It's located on top of the throttle body, unbolt the two bolts, spray some carb cleaner in the iac and clean it out with a rag as best you can, and clean the mounting plate on the throttle body too, bolt it on and see if that helps.
-Thomas

1988 Notch Mustang: - 438W, direct port n2o, t56
2003 SVT Focus: - SCT X3 tuner
Thomas is offline  
post #11 of 12 (permalink) Old 01-25-2005, 11:19 PM
 
Join Date: Sep 2003
Posts: 882
I will try that and see how it goes.

The 5.0 TB bolts up to the 3.8 intake?
sc0tty8 is offline  
post #12 of 12 (permalink) Old 01-25-2005, 11:28 PM
Moderator
Iowa Chapter Director
Uber Luber
TCCoAAC Member
Moderator
 
Thomas's Avatar
 
Join Date: Jul 2002
Location: Ames, Iowa
Age: 35
Posts: 8,978
Quote:
Originally Posted by sc0tty8

The 5.0 TB bolts up to the 3.8 intake?
No, I have an adaptor plate but you could drill new holes into the throttle body. I also spliced in the 5.0 wiring harness for the tps and iac, and the throttle linkage bracket is modified too.

1988 Notch Mustang: - 438W, direct port n2o, t56
2003 SVT Focus: - SCT X3 tuner
Thomas is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TCCoA Forums 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:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome