1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

rough idle

Thread Tools
 
Search this Thread
 
Old 01-27-2010, 07:18 PM
  #11  
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 28 Likes on 24 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

That'* a good point. Unplugging the TPS will be a zero signal.
Old 01-27-2010, 07:18 PM
  #12  
Member
Posts like a V-Tak
Thread Starter
 
jcrazyjj's Avatar
 
Join Date: Aug 2009
Posts: 79
Likes: 0
Received 0 Likes on 0 Posts
jcrazyjj is on a distinguished road
Default

Originally Posted by Danthurs
No, leave the TPS plugged in. Try unplugging the MAF and start it. It will run rough for a bit and then smooth out. If the problem goes away then your MAF is bad. If there'* no change, the MAF is good.
it runs rough then smooths out anyway. im kinda confused.
Old 01-27-2010, 07:19 PM
  #13  
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 28 Likes on 24 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

Inspect the MAF. Tap on it, does the engine stumble? Can you see the thin wire in the MAF?
Old 01-27-2010, 07:22 PM
  #14  
Member
Posts like a V-Tak
Thread Starter
 
jcrazyjj's Avatar
 
Join Date: Aug 2009
Posts: 79
Likes: 0
Received 0 Likes on 0 Posts
jcrazyjj is on a distinguished road
Default

i unplugged the TPS while the car was idling and i didnt notice a change in the 10 seconds it was unplugged. I didnt look for a check engine light while it was unplugged and it hasnt shown one at all since i have owned it.

Originally Posted by Danthurs
Inspect the MAF. Tap on it, does the engine stumble? Can you see the thin wire in the MAF?
its dark and cold out right now. ill check that tomorrow.

what and how should i test these parts?

Last edited by jcrazyjj; 01-27-2010 at 07:23 PM.
Old 01-27-2010, 08:02 PM
  #15  
Senior Member
Certified GM nut
 
SignOfZeta's Avatar
 
Join Date: Mar 2005
Location: New Milford, CT
Posts: 2,284
Received 17 Likes on 14 Posts
SignOfZeta has a spectacular aura aboutSignOfZeta has a spectacular aura about
Default

Originally Posted by jcrazyjj
I didnt look for a check engine light while it was unplugged and it hasnt shown one at all since i have owned it
You haven't ever had a check engine light? When you turn the key to RUN, does the check engine light come on?

If so, then you and your car are very lucky!

If not, then your light is burned out. If you've been getting check engine "lights," then you've never been told. Plug in a code reader and be prepared for a possible laundry list of codes.
Old 01-27-2010, 08:09 PM
  #16  
Senior Member
Posts like a Camaro
 
onesweetride's Avatar
 
Join Date: Oct 2009
Posts: 1,012
Likes: 0
Received 0 Likes on 0 Posts
onesweetride is on a distinguished road
Default

Originally Posted by Danthurs
The only other thing could be the throttle position sensor.
I agree. Check for codes.I have a '97.Mines looping when first started usually stalls on first start up. Hot or cold threw codes po121 TP sensor & code po108 map sensor.
Old 01-27-2010, 08:11 PM
  #17  
Member
Posts like a V-Tak
Thread Starter
 
jcrazyjj's Avatar
 
Join Date: Aug 2009
Posts: 79
Likes: 0
Received 0 Likes on 0 Posts
jcrazyjj is on a distinguished road
Default

Originally Posted by SignOfZeta
You haven't ever had a check engine light? When you turn the key to RUN, does the check engine light come on?

If so, then you and your car are very lucky!

If not, then your light is burned out. If you've been getting check engine "lights," then you've never been told. Plug in a code reader and be prepared for a possible laundry list of codes.
im beginning to think thats its burnt out. i had it ran for codes at autozone a while back and it had like 3 i think and i actually still have the sheets now that you mention it. thanks for refreshing my memory.

i have a P0102 code and a P0446.

so MAF it is?

Originally Posted by onesweetride
I agree. Check for codes.I have a '97.Mines looping when first started usually stalls on first start up. Hot or cold threw codes po121 TP sensor & code po108 map sensor.
mine occasionally stalls as well and i figured that had to do with the rough idle not giving enough fuel.

Last edited by jcrazyjj; 01-27-2010 at 08:13 PM.
Old 01-27-2010, 11:26 PM
  #18  
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 28 Likes on 24 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

102 is the MAF, and 446 is the EVAP vent performance. I'm thinking about a vacuum leak in the EVAP system.
Old 01-28-2010, 04:06 AM
  #19  
Member
Posts like a V-Tak
Thread Starter
 
jcrazyjj's Avatar
 
Join Date: Aug 2009
Posts: 79
Likes: 0
Received 0 Likes on 0 Posts
jcrazyjj is on a distinguished road
Default

Originally Posted by Danthurs
102 is the MAF, and 446 is the EVAP vent performance. I'm thinking about a vacuum leak in the EVAP system.
what would be the best way to test/locate the vacuum leak? im gonna take out the MAF today and see its condition and run to autozone to have then run for codes.
Old 01-28-2010, 07:23 AM
  #20  
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 28 Likes on 24 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

Your just going to have to inspect the vacuum lines. Look for cracked or brittle lines.


Quick Reply: rough idle



All times are GMT -4. The time now is 10:51 PM.