All times are UTC - 6 hours [ DST ]




Ask A Question Reply   
Author Message
 

contributions: 7
I have a 1999 mercury mountaineer 4.0 sohc v6 engine. it is hard to start and runs rough in cold weather until engine warms up, acts like old carb engine that the choke does not work on. has no codes logged. I have tried to check the iat sensor, but there is not one in the intake pipe where the book that i have says it should be. truck has alot of miles on it, but runs good when it warms up and does not use any oil. can anyone help me/ thanks


Share on FacebookShare on DiggShare on DeliciousShare on TechnoratiShare on TumblrShare on Google+
   
Reply with quote  
* Search   
 
User avatar

contributions: 2256
Images: 37
Location: Oregon
when it is cold and running rough you might want to check for a vacuum leak into the intake manifold.


   
Reply with quote  
 

contributions: 7
I will recheck for leaks, but it does not act like a vacuum leak, it idles too smooth when engine warms up. also it cranks and runs smooth when outside air temp is warm. what about the intake air sensor. thanks


   
Reply with quote  
 
User avatar

contributions: 2256
Images: 37
Location: Oregon
the vacuum leak may go away as the engine warms up and parts expand with heat. Just as an exhaust leak may be present on a cold engine but goes away as the engine warms up. As the leaks worsens it may eventually become too big such that it will continue to show up even after the engine warms up.

what makes you think you have a problem with the IAT? before you worry about a bad sensor you should scan it's value. With the engine cold (like first thing in the morning before you start your engine) scan your data stream. your coolant temp and your air temp should be within a couple of degrees of each other. Once you start your engine the temperatures will change at different rates so that test will no longer be valid.

if your mass air flow sensor uses all six wire connections the IAT is built inside MAF


   
Reply with quote  
 

contributions: 7
thanks I will do that


   
Reply with quote  
Ask A Question Reply   

   Similar Topics   Author   Replies   Views   Most Recent 
New Articles View the first Mercury cougar-1999

in Ford Cars

Lyon007

1

230

Tue Jun 26, 2018 12:05 am

carriedi View the latest

New Articles View the first '97 Mercury Sable-How to Refill Coolant After Overheating

in Ford Cars

PS85

1

2027

Mon Jun 19, 2017 1:55 am

carriedi View the latest

New Articles View the first 1999 Ford Explorer Brake pedal down

in Ford Trucks

ajhank

3

1986

Thu Feb 25, 2016 11:42 am

carriedi View the latest

New Articles View the first What engine do I have?

in Ford Trucks

cestes001

1

749

Tue Apr 25, 2017 11:41 pm

carriedi View the latest

New Articles View the first Ford e150 van Engine stalling

in Ford Trucks

sr069w

5

3502

Wed Apr 13, 2016 1:03 am

carriedi View the latest

New Articles View the first Electrical problem with 2004 Ford 250 4X4, 5.4 L engine

in Ford Trucks

1208doug48

2

3530

Mon Jan 11, 2016 7:15 pm

carriedi View the latest

New Articles View the first 2003 CHEVY SILVERADRO 5.3 T ENGINE WON'T START

in Ford Trucks

ronnie310

4

2585

Fri Jul 08, 2016 12:01 am

carriedi View the latest


All times are UTC - 6 hours [ DST ]



Search for:
Jump to:  
Contact Us