3rd Gen / L98 Engine Tech 1982 - 1992 Engine Related

Starts and stalls/ rough idle

Thread Tools
 
Search this Thread
 
Old 06-16-2006, 10:18 AM
  #1  
Registered User
Thread Starter
 
fraser11's Avatar
 
Join Date: Jun 2006
Posts: 5
Starts and stalls/ rough idle

im from australia, i recently got a 1990 iroc z camaro 5.7lt, it was fine for awhile however now when it is dead cold it starts and straight away stalls, if i give it a bit of gas i can get it to idle, however it idles low and seems to surge. once at operating temp i have no problems, would it have anything to do with cold idle?? coolant temp sensor??
fraser11 is offline  
Old 06-16-2006, 11:49 AM
  #2  
Registered User
 
Black305RS's Avatar
 
Join Date: Apr 2005
Location: Elgin,IL
Posts: 247
Re: Starts and stalls/ rough idle

i have the same problem with my 89 irov 5.0 i havent beeen able to figure it out either and no one on the 4 sites i posted it on has any idea reall. my teacher did say to check the coolant temperature circuit to make sure its reading properly because it could cause the car to run richer on startup. yesterday i repaired my coolant ttemp sensor but i havent started it yet. ill let you know the results when i do.
Black305RS is offline  
Old 06-16-2006, 12:14 PM
  #3  
Registered User
 
Black305RS's Avatar
 
Join Date: Apr 2005
Location: Elgin,IL
Posts: 247
Re: Starts and stalls/ rough idle

i just started the car and it didnt fix it. so i tried unplugging the maf and as soon as i did that the idle picked up and its currently idling fine with the maf unplugged. its throwing a code though.
Black305RS is offline  
Old 06-16-2006, 07:14 PM
  #4  
Registered User
 
IROC-T's Avatar
 
Join Date: Jun 2003
Location: So.Cal on the Best coast
Posts: 866
Re: Starts and stalls/ rough idle

Clean and check the IAC sensor, that's the one on bottom of the TB. They tend to cabon-up, and can cause an erratic idle.
IROC-T is offline  
Old 06-16-2006, 07:38 PM
  #5  
Registered User
Thread Starter
 
fraser11's Avatar
 
Join Date: Jun 2006
Posts: 5
Re: Starts and stalls/ rough idle

ok well ill try disconecting the maf and let you no. ill try cleaning the iac sensor to, it cant hurt thanks
fraser11 is offline  
Old 06-16-2006, 08:14 PM
  #6  
Registered User
 
Pneumatic_Tire's Avatar
 
Join Date: May 2004
Location: Kettering Ohio
Posts: 439
Re: Starts and stalls/ rough idle

check all your plug wires resistance with a ohm meter, and look for burns from laying across the exhaust, check the firing order, and check the plugs.
Pneumatic_Tire is offline  
Old 06-17-2006, 01:59 AM
  #7  
Registered User
 
BrandonKeith's Avatar
 
Join Date: Mar 2005
Location: Oregon
Posts: 105
Re: Starts and stalls/ rough idle

I really doubt that it's a plug wire issue since the problem goes away after the engine warms up.. It's definately the IAC. Pull that bad boy out and spray the hell out of it with some good carb and choke cleaner.

Problem should go away and the car should be running great.
BrandonKeith is offline  
Old 06-17-2006, 06:38 AM
  #8  
Registered User
 
Pneumatic_Tire's Avatar
 
Join Date: May 2004
Location: Kettering Ohio
Posts: 439
Re: Starts and stalls/ rough idle

Originally Posted by BrandonKeith
I really doubt that it's a plug wire issue since the problem goes away after the engine warms up.. It's definately the IAC. Pull that bad boy out and spray the hell out of it with some good carb and choke cleaner.

Problem should go away and the car should be running great.
it still can be a plug wire, wont hurt to check the easiest things first. It can go away becuase the high heat a hot engine creates helps combustion, and can make an arcing or burned plug wire problem subside alot. I know from experience lol. I had a plug wire burn through on one side cause it somehow got up against my header. It had a rough idle, but almost completely went away when it was hot.

EDIT, glad you found your problem.
Pneumatic_Tire is offline  
Old 06-17-2006, 01:10 PM
  #9  
Registered User
 
IROC-T's Avatar
 
Join Date: Jun 2003
Location: So.Cal on the Best coast
Posts: 866
Re: Starts and stalls/ rough idle

Originally Posted by Black305RS
i just started the car and it didnt fix it. so i tried unplugging the maf and as soon as i did that the idle picked up and its currently idling fine with the maf unplugged. its throwing a code though.
Pulling the plug on the MAF causes an open loop (limp home mode) which makes it run richer, that's why it idles up. Your code will probably be a 34.
IROC-T is offline  
Old 06-17-2006, 03:16 PM
  #10  
Registered User
 
Black305RS's Avatar
 
Join Date: Apr 2005
Location: Elgin,IL
Posts: 247
Re: Starts and stalls/ rough idle

Originally Posted by IROC-T
Pulling the plug on the MAF causes an open loop (limp home mode) which makes it run richer

yes but the the problem is on cold startup only. And on cold startup the car is always in "limp mode". so unplugging the maf will make no difference IMO. That is why i believe a gunked up maf is the cause of my poor idle on cold startup ONLY. ya see when i unplug ed the MAF the idle became normal and when i plugged it back in 2 seconds later it became erratic again so until i have time to clean it i guess ill be running in "Limp Mode" at least this way i wont have to fight to keep the car going in the morning.
hope im not coming off as an *** here cause thats not my intention.

thanks pneumatic tire i am too.

Last edited by Black305RS; 06-17-2006 at 04:25 PM.
Black305RS is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Fatdog2
LT1 Based Engine Tech
1
02-13-2015 08:19 PM
Iamherefornow
LT1 Based Engine Tech
2
01-26-2015 04:57 PM
bfmv13trivium
General 1967-2002 F-Body Tech
9
01-14-2015 09:57 AM
Scottylt1
General 1967-2002 F-Body Tech
3
01-08-2015 02:48 PM
TrouserSnake
Midwest
0
07-29-2002 11:24 PM



Quick Reply: Starts and stalls/ rough idle



All times are GMT -5. The time now is 10:29 AM.