5.0L (1979-1995) Mustang Technical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.

Mass Air Meter Problems

Thread Tools
 
Search this Thread
 
Old 11-18-2009, 11:49 AM
  #1  
bouchermb
4th Gear Member
Thread Starter
 
bouchermb's Avatar
 
Join Date: Apr 2006
Location:
Posts: 1,306
Default Mass Air Meter Problems

I purchased a Pro M 95mm mass air meters for his 89 mustang a little less than two years ago. When we installed the meter, the car ran beautifully. After a few months suddenly it began to run terrible. It surges badly, won't idle from a cold start, and any time you give it a little throttle it dies. You basically can't drive the car. Long story made short. I scanned the computer for error codes and everything checked out ok except for one. We found a mass air meter error code. It was mass air meter below 0.4 volts during the last 80 warm ups. Also, He has a wide band 02 sensor with a meter. What we observed was during a cold start up the meter will read from 12:1 to 17:1 afr then after a second or two it'll go lean, off the meter lean like the engine's just not receiving any fuel. Try starting the car again and it repeats this act. When the engine starts to get a little heat in it, it will idle ok for a few seconds but as soon as you give it the slightest amount of throttle it starts acting up again. I am tending to believe that the problem is with the air meter.

Any idea on how to trouble shoot the meter to make sure it's the problem?
bouchermb is offline  
Old 11-18-2009, 03:23 PM
  #2  
89stangbanga
1st Gear Member
 
89stangbanga's Avatar
 
Join Date: Oct 2009
Location: California
Posts: 50
Default

Originally Posted by bouchermb
I purchased a Pro M 95mm mass air meters for his 89 mustang a little less than two years ago. When we installed the meter, the car ran beautifully. After a few months suddenly it began to run terrible. It surges badly, won't idle from a cold start, and any time you give it a little throttle it dies. You basically can't drive the car. Long story made short. I scanned the computer for error codes and everything checked out ok except for one. We found a mass air meter error code. It was mass air meter below 0.4 volts during the last 80 warm ups. Also, He has a wide band 02 sensor with a meter. What we observed was during a cold start up the meter will read from 12:1 to 17:1 afr then after a second or two it'll go lean, off the meter lean like the engine's just not receiving any fuel. Try starting the car again and it repeats this act. When the engine starts to get a little heat in it, it will idle ok for a few seconds but as soon as you give it the slightest amount of throttle it starts acting up again. I am tending to believe that the problem is with the air meter.

Any idea on how to trouble shoot the meter to make sure it's the problem?
That could also be your TPS. THrottle position sensor. Mine went bad on my car, it would only start when i hit it with starting fluid from autozone, then as soon as i give it gas it would sputter and eventually die after a few seconds.
89stangbanga is offline  
Old 11-18-2009, 03:35 PM
  #3  
bouchermb
4th Gear Member
Thread Starter
 
bouchermb's Avatar
 
Join Date: Apr 2006
Location:
Posts: 1,306
Default

Already checked that out and it seemed to be OK.
bouchermb is offline  
Old 11-18-2009, 07:36 PM
  #4  
mjr46
D.R. THE PATHETIC DORK
 
mjr46's Avatar
 
Join Date: Jun 2007
Location: West Virginia
Posts: 30,863
Default

Do you have a spare meter that is calibrated for your inj needs??? quickest thing you could do is swap on a known good meter, I have a bunch of friends around here that will let me borrow there's to check such often
mjr46 is offline  
Old 11-19-2009, 07:23 AM
  #5  
bouchermb
4th Gear Member
Thread Starter
 
bouchermb's Avatar
 
Join Date: Apr 2006
Location:
Posts: 1,306
Default

That was my next course of action, but I don't know of someone that has a spare meter that's calibrated to my injectors.
bouchermb is offline  
Old 11-19-2009, 11:15 AM
  #6  
mattdel
6th Gear Member
 
mattdel's Avatar
 
Join Date: Nov 2006
Location: Spfld, MA
Posts: 9,240
Default

craigslist is your friend. bet you can find someone local that will come over and let you swap out for testing for a quick $20
mattdel is offline  
Old 11-19-2009, 06:38 PM
  #7  
bouchermb
4th Gear Member
Thread Starter
 
bouchermb's Avatar
 
Join Date: Apr 2006
Location:
Posts: 1,306
Default

Worth a shot and I'll give it a look.
bouchermb is offline  
Old 03-01-2010, 07:23 PM
  #8  
tam85
 
tam85's Avatar
 
Join Date: Oct 2009
Location: illinois
Posts: 3
Default

yeah i agree, it could be your throttle position sensor that caused your air mass meter not to function well. if you want to troubleshoot it here's how http://www.ehow.com/how_4489318_trou...ps-sensor.html
tam85 is offline  
Old 03-01-2010, 08:37 PM
  #9  
AdderMk2
Banned
 
AdderMk2's Avatar
 
Join Date: Dec 2005
Location: Lil' Rhody
Posts: 22,376
Default

Originally Posted by tam85
yeah i agree, it could be your throttle position sensor that caused your air mass meter not to function well. if you want to troubleshoot it here's how http://www.ehow.com/how_4489318_trou...ps-sensor.html


holy ****... are you serious noobie???

this thread is from LAST YEAR.... dont be stupid. digging up old threads to further ask for advise is one thing... but dont ADD more advise so far after the thread died
AdderMk2 is offline  
Old 03-01-2010, 09:53 PM
  #10  
mjr46
D.R. THE PATHETIC DORK
 
mjr46's Avatar
 
Join Date: Jun 2007
Location: West Virginia
Posts: 30,863
Default

Originally Posted by tam85
yeah i agree, it could be your throttle position sensor that caused your air mass meter not to function well. if you want to troubleshoot it here's how http://www.ehow.com/how_4489318_trou...ps-sensor.html
lol, crazy noob..........do you even know the difference between input and output devices??? FYI THE MAF as well as the TPS are both inputs....please explain how in the "F" ONE INPUT AFFECTS another??? EXACTLY, INPUTS AFFECT output commands = garbage in garbage out.......
mjr46 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Granatelli Sales
S550 2015-2023 Mustang
22
01-20-2020 12:34 AM
musnicki
Classic Mustang General Discussion
8
09-23-2015 07:11 AM
5.0 kevo
5.0L (1979-1995) Mustang
6
09-03-2015 06:24 PM



Quick Reply: Mass Air Meter Problems



All times are GMT -5. The time now is 02:27 PM.