V6 Discussion and questions about the base carbureted or MPFI V6's and the rare SFI Turbo V6.

Car is running bad on hot days

Thread Tools
 
Search this Thread
 
Old 08-08-2014, 02:00 AM
  #1  
Member

Thread Starter
 
sheltonw3's Avatar
 
Join Date: Sep 2002
Location: Hellfire and Brimstone!...A.K.A. portland
Posts: 323
Likes: 0
Received 0 Likes on 0 Posts
Car: 91' TRANS AM Modified
Engine: Classified
Transmission: Auto with Overdrive
Car is running bad on hot days

Every other day when it is cool, the car runs good, but on the hotter days is runs like crap, and struggles, I did a ECM reset, and it just smooth's out on the days on the 80's, but I the 90's it just acts like it want to die, is It possible a temp sensor might be defective?...and if so, where is it on a 3.1 liter engine???...I have replaced the IAC, TPS, cleaned out the throttle body, is it possible the ECM is going bananas?...WTH???
Old 08-08-2014, 01:36 PM
  #2  
Supreme Member

 
Gumby's Avatar
 
Join Date: Oct 2001
Location: NWOhioToledoArea
Posts: 8,113
Likes: 0
Received 5 Likes on 5 Posts
Car: 86-FireBird
Engine: -MPFI
Transmission: T5
Axle/Gears: 3:42
Re: Car is running bad on hot days

get the temps to stay well under 200F

remove ac rad if broke, good air dam, true cold air that comes directly from outside the car.
Old 08-08-2014, 01:41 PM
  #3  
Supreme Member

iTrader: (2)
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: South Ms
Posts: 4,437
Received 725 Likes on 494 Posts
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: Car is running bad on hot days

Try replacing your coil
Old 08-08-2014, 06:24 PM
  #4  
Supreme Member

iTrader: (4)
 
RubberDucky's Avatar
 
Join Date: Mar 2009
Location: Florida
Posts: 2,035
Received 28 Likes on 16 Posts
Car: 1989 Camaro RS
Engine: LH6
Transmission: T56
Axle/Gears: 3.42 Auburn Posi
Re: Car is running bad on hot days

Originally Posted by Gumby
get the temps to stay well under 200F

remove ac rad if broke, good air dam, true cold air that comes directly from outside the car.
This. These motors hate the temps they run at, I run coolant with some water wetter and it works well. I've been considering getting a better fan as well.
Old 08-08-2014, 09:13 PM
  #5  
Supreme Member

 
Gumby's Avatar
 
Join Date: Oct 2001
Location: NWOhioToledoArea
Posts: 8,113
Likes: 0
Received 5 Likes on 5 Posts
Car: 86-FireBird
Engine: -MPFI
Transmission: T5
Axle/Gears: 3:42
Re: Car is running bad on hot days

One of the first things I noticed when I first got the car and did anything to it, it ran crisp and responsive on the way to work, in the heat of day coming home, I had to push it more and more.

Once I got the temps to stay well under 200F all the time, it runs crisp and responsive all the time. I don't even need a fan, only if I sit at a long line at the bank or drive thru does it need to come on.

long as its moving, it doesn't need to run.
1-2 times a month do I click it on.
Old 08-09-2014, 04:22 AM
  #6  
Member

Thread Starter
 
sheltonw3's Avatar
 
Join Date: Sep 2002
Location: Hellfire and Brimstone!...A.K.A. portland
Posts: 323
Likes: 0
Received 0 Likes on 0 Posts
Car: 91' TRANS AM Modified
Engine: Classified
Transmission: Auto with Overdrive
Re: Car is running bad on hot days

Just on hot days when the car has gone nowhere @ start up, it runs terribly, but on the cooler days @ first start up it runs okay, not quite sure, but I will see about doing a test run tomorrow and see if it tires to die?

Last edited by sheltonw3; 08-09-2014 at 04:23 AM. Reason: C
Old 08-09-2014, 02:33 PM
  #7  
Member
 
Stewie's Avatar
 
Join Date: May 2012
Location: Richmond, VA
Posts: 251
Likes: 0
Received 0 Likes on 0 Posts
Car: 1992 Firebird
Engine: 3.1L
Transmission: Manual T5
Axle/Gears: Stock
Re: Car is running bad on hot days

Originally Posted by sheltonw3
Every other day when it is cool, the car runs good, but on the hotter days is runs like crap, and struggles, I did a ECM reset, and it just smooth's out on the days on the 80's, but I the 90's it just acts like it want to die, is It possible a temp sensor might be defective?...and if so, where is it on a 3.1 liter engine???...I have replaced the IAC, TPS, cleaned out the throttle body, is it possible the ECM is going bananas?...WTH???
Don't know if the coolant temperature sensor could cause this. But, since you asked, it is on the driver's side of the engine block. A new one costs about $11.
Old 08-13-2014, 09:22 PM
  #8  
Member

Thread Starter
 
sheltonw3's Avatar
 
Join Date: Sep 2002
Location: Hellfire and Brimstone!...A.K.A. portland
Posts: 323
Likes: 0
Received 0 Likes on 0 Posts
Car: 91' TRANS AM Modified
Engine: Classified
Transmission: Auto with Overdrive
Re: Car is running bad on hot days

I get a code 45, but it sometimes starts rough then the idle smooth's down, but on hot days, it just idles really bad, I tried to clean the Throttle body some more, but it took a while to smooth out again, but the [SES] sometimes it comes on and then I shut it off and restart, then the [SES] goes off, plus at other time the [SES]-[BRAKE] & [SECURITY] lights trickle when I turn it over, then the security light stays on for an extra 10 seconds, that has never happened before.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
theshackle
Tech / General Engine
4
03-05-2017 06:37 PM
thefirebirdm@n
South Central Region
3
09-14-2015 01:45 PM
TheExaminer
Cooling
26
08-26-2015 04:59 PM
mustangman65_79
Body
3
08-11-2015 03:17 PM
1992 Trans Am
Engine/Drivetrain/Suspension Parts for Sale
1
08-08-2015 08:16 PM



Quick Reply: Car is running bad on hot days



All times are GMT -5. The time now is 06:14 AM.