IS - 2nd Gen (2006-2013) Discussion about the 2006+ model IS models

Rough idle at start with codes

Thread Tools
 
Search this Thread
 
Old 10-27-19, 09:21 AM
  #1  
Petet
Lead Lap
Thread Starter
 
Petet's Avatar
 
Join Date: Mar 2018
Location: Mass
Posts: 421
Likes: 0
Received 36 Likes on 31 Posts
Default Rough idle at start with codes

I started my car today and it was running rough, engine light came on. Shut it down restarted and ran fine. Checked codes PO172 and PO175 bank 1 and bank 2. Cleared codes and it seems to be running fine. About a month ago car started then died but haven’t had any issues till now. Mass air flow sensor ?
Old 10-27-19, 01:16 PM
  #2  
Petet
Lead Lap
Thread Starter
 
Petet's Avatar
 
Join Date: Mar 2018
Location: Mass
Posts: 421
Likes: 0
Received 36 Likes on 31 Posts
Default

Cleaned the sensor all seams to be good. Maybe just order a new one to be on the safe side.
Old 10-27-19, 01:23 PM
  #3  
MikeFig82
Lead Lap
iTrader: (13)
 
MikeFig82's Avatar
 
Join Date: Nov 2013
Location: Texas
Posts: 4,089
Received 773 Likes on 675 Posts
Default

If you have an OBDII scanner with live data. You can just monitor what the MAF is doing at idle, and on load. Also if it has freeze frame data best to look at what the data looks like first.
Old 10-27-19, 07:04 PM
  #4  
Petet
Lead Lap
Thread Starter
 
Petet's Avatar
 
Join Date: Mar 2018
Location: Mass
Posts: 421
Likes: 0
Received 36 Likes on 31 Posts
Default

It does have live data. I’ll watch it, And look back on some old posts what the values should be.
I panicked when the light came on. Last and first time was due to a valve spring failure causing the motor to blow.
Old 10-28-19, 08:24 AM
  #5  
Gville350
Moderator
iTrader: (10)
 
Gville350's Avatar
 
Join Date: Mar 2011
Location: South Carolina
Posts: 11,574
Likes: 0
Received 433 Likes on 385 Posts
Default

The "started, then died" comment sounds like what happens right after you have the battery disconnected for a little bit. It does this normally upon the FIRST re-start after the "reset" (aka, having the battery disconnected).

Have you messed with the MAF or the intake recently? Perhaps a slight leak somewhere where something wasn't fully tightened...perhaps the tube onto the TB?
Old 10-28-19, 04:37 PM
  #6  
Petet
Lead Lap
Thread Starter
 
Petet's Avatar
 
Join Date: Mar 2018
Location: Mass
Posts: 421
Likes: 0
Received 36 Likes on 31 Posts
Default

No changes for months. I cut the air box about 2 months ago and it’s been fine since. Our temps here dropped about 20 deg since last time I dove it which was only a day before.
I plugged my scanner in today while driving. Not sure what the values should be but it looked good. Lol. At idle was about 8 under throttle it would go up.
Old 10-28-19, 04:45 PM
  #7  
MikeFig82
Lead Lap
iTrader: (13)
 
MikeFig82's Avatar
 
Join Date: Nov 2013
Location: Texas
Posts: 4,089
Received 773 Likes on 675 Posts
Default

Originally Posted by Petet
No changes for months. I cut the air box about 2 months ago and it’s been fine since. Our temps here dropped about 20 deg since last time I dove it which was only a day before.
I plugged my scanner in today while driving. Not sure what the values should be but it looked good. Lol. At idle was about 8 under throttle it would go up.
At idle it was 8 g/s??? Its should be close to engine displacement at idle. If its 8 g/s the maf has issues.

At idle what's your fuel trims look like? Short and long term?
Old 10-30-19, 02:15 PM
  #8  
Petet
Lead Lap
Thread Starter
 
Petet's Avatar
 
Join Date: Mar 2018
Location: Mass
Posts: 421
Likes: 0
Received 36 Likes on 31 Posts
Default

I had to buy a new scan tool, mine was acting funny.
so at idle the air flow is 3.5g/s when at idle & operating temp.

Old 10-30-19, 03:28 PM
  #9  
MikeFig82
Lead Lap
iTrader: (13)
 
MikeFig82's Avatar
 
Join Date: Nov 2013
Location: Texas
Posts: 4,089
Received 773 Likes on 675 Posts
Default

Originally Posted by Petet
I had to buy a new scan tool, mine was acting funny.
so at idle the air flow is 3.5g/s when at idle & operating temp.
Those number look ok. One question do you have an after market filter in place? I notice this with mine having an AEM dryflow. It will add fuel on idle bank 2 to to 5% long term. With stock filter all my short trims will be 0 longs will be -2 to -3 both banks at idle once warmed up.
Old 10-31-19, 01:39 AM
  #10  
Petet
Lead Lap
Thread Starter
 
Petet's Avatar
 
Join Date: Mar 2018
Location: Mass
Posts: 421
Likes: 0
Received 36 Likes on 31 Posts
Default

Stock air filter. It has about 30k on it. Time to replace it.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
shark13
RX - 1st Gen (1999-2003)
15
06-21-14 01:03 AM
jre1638
RX - 1st Gen (1999-2003)
7
04-28-11 10:07 PM
COOLIS
RX - 1st Gen (1999-2003)
3
05-04-09 10:45 AM
Seize
GS - 1st Gen (1993-1997)
17
08-08-05 12:08 PM
sweetsc400
Performance & Maintenance
1
05-07-03 04:53 PM



Quick Reply: Rough idle at start with codes



All times are GMT -7. The time now is 04:16 PM.