Start/No Start & MAPP Sensor Unplugged - Ford Powerstroke Diesel Forum

 
LinkBack Thread Tools Display Modes
post #1 of 6 Old 03-05-2013, 01:17 PM Thread Starter
LBR
Powerstroke.org Rookie
 
Join Date: Apr 2012
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Start/No Start & MAPP Sensor Unplugged

Hi Guys…another newbie with 6.0 problems….my truck is a 2003 F-550 Chassis Cab 4x2 which I purchased in May/2005 with 22K miles on the clock. The previous owner used it for towing a huge 5er.

Besides a six year problem with 1) batteries going dead after 3 days of non-use and in the last two years 2) won’t start nor fire half the time, one day it lost virtually all (95%) engine power. After quite a long process, the local shop found with the MAPP sensor plugged in, it would barely escape it’s own shadow, but with it unplugged, it runs like a John Force Racing F/C, with the only down side being the infamous ‘Check Engine’ light on. A brand new MAPP sensor was put in, but made no difference. After some research, they are getting more confused about why when the MAPP sensor is unplugged, it runs great.

A friend told me that possibly the previous owner had chipped the ECM (Superchip?) and if that tune had been removed before me buying it, some of the performance enhancing files may be creating havoc with the ECM, similar to a computer virus if you may. Are we on the right track with this thinking? So it was suggested to have the ECM completely formatted, then reprogrammed in case some stray aftermart performance data is the culprit. By a friend’s suggestion, I’m thinking of having it done by IH with their tune in the ECM. Thanx in advance.
LBR is offline  
post #2 of 6 Old 03-14-2013, 09:44 AM Thread Starter
LBR
Powerstroke.org Rookie
 
Join Date: Apr 2012
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Quote:
Originally Posted by LBR View Post
Hi Guys…another newbie with 6.0 problems….my truck is a 2003 F-550 Chassis Cab 4x2 which I purchased in May/2005 with 22K miles on the clock. The previous owner used it for towing a huge 5er.

Besides a six year problem with 1) batteries going dead after 3 days of non-use and in the last two years 2) won’t start nor fire half the time, one day it lost virtually all (95%) engine power. After quite a long process, the local shop found with the MAPP sensor plugged in, it would barely escape it’s own shadow, but with it unplugged, it runs like a John Force Racing F/C, with the only down side being the infamous ‘Check Engine’ light on. A brand new MAPP sensor was put in, but made no difference. After some research, they are getting more confused about why when the MAPP sensor is unplugged, it runs great.

A friend told me that possibly the previous owner had chipped the ECM (Superchip?) and if that tune had been removed before me buying it, some of the performance enhancing files may be creating havoc with the ECM, similar to a computer virus if you may. Are we on the right track with this thinking? So it was suggested to have the ECM completely formatted, then reprogrammed in case some stray aftermart performance data is the culprit. By a friend’s suggestion, I’m thinking of having it done by IH with their tune in the ECM. Thanx in advance.
Well, looks like no one here knows the answer either...Thanx for reading anyway.
LBR is offline  
post #3 of 6 Old 03-14-2013, 12:31 PM
Premium Member

 
twoicebergs's Avatar
 
Join Date: Sep 2008
Location: Oakbank, Manitoba
Posts: 3,428
Thanks: 8
Thanked 125 Times in 117 Posts
Mentioned: 4 Post(s)
Quoted: 36 Post(s)
Feedback Score: 0 reviews
Your MAF (not MAP) and EGR valve may be part of the problem. However, without any further info from a monitor or diagnostic tools it is tough to give you any good help over the internet. If you go to the 6.0l coffee table book or the repair manual, you can see the MAP is more of information versus controlling parameters.

• The PCM uses the MAP sensor signal to assist in the calculation of EGR duty cycle.

• The PCM measures the MAP signal to determine intake manifold (boost) pressure.

So, if it is screwing up the EGR duty cycle, that would give you lousy performance. Since you changed the sensor, that would be an indication you may have a wiring problem or your EGR valve may not be working correctly. I would start by cleaning and verifying the correct operation of the EGR valve.

Frank
2007 F-250 Lariat Crew. MBM 190/50s,
KC-68 Stage 3 Turbo,
DashBoss/F/P, and a few other goodies
Stiction Problems - Fix it yourself! - http://www.powerstroke.org/forum/gen...ml#post4509754
Want to modify your injectors DIY - http://www.powerstroke.org/forum/6-0...ger-flows.html

Working for Toys
twoicebergs is offline  
post #4 of 6 Old 03-18-2013, 09:09 AM Thread Starter
LBR
Powerstroke.org Rookie
 
Join Date: Apr 2012
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Quote:
Originally Posted by twoicebergs View Post
Your MAF (not MAP) and EGR valve may be part of the problem. However, without any further info from a monitor or diagnostic tools it is tough to give you any good help over the internet. If you go to the 6.0l coffee table book or the repair manual, you can see the MAP is more of information versus controlling parameters.

• The PCM uses the MAP sensor signal to assist in the calculation of EGR duty cycle.

• The PCM measures the MAP signal to determine intake manifold (boost) pressure.

So, if it is screwing up the EGR duty cycle, that would give you lousy performance. Since you changed the sensor, that would be an indication you may have a wiring problem or your EGR valve may not be working correctly. I would start by cleaning and verifying the correct operation of the EGR valve.
Thank you for the info....

We were told that without the MAP sensor plugged in, performance would be poorer rather than better, such as in my case. Also there would probably have to be a program that would supersede the MAP signal, such as a Superchips in the ECM. With your explanation, it becomes apparent the the MAP is for reading information purposes more so than the controlling a function.

So with it being unplugged, do you think that in itself would allow the turbo to boost up more since the ECM cannot read the MAP sensor for intake pressures? This truck has never run this strong, so could I be over-boosting at WOT and should be concerned? The EGR is on the list to clean...Lance
LBR is offline  
post #5 of 6 Old 03-18-2013, 09:33 AM
Premium Member

 
twoicebergs's Avatar
 
Join Date: Sep 2008
Location: Oakbank, Manitoba
Posts: 3,428
Thanks: 8
Thanked 125 Times in 117 Posts
Mentioned: 4 Post(s)
Quoted: 36 Post(s)
Feedback Score: 0 reviews
It doesn't use MAP to control boost, just EGR duty cycle. However, it will use it and a few other parameters to set codes if parameters are exceeded. The boost is a function of EBP and vane position, not the other way around, even if EBP is inferred.

Frank
2007 F-250 Lariat Crew. MBM 190/50s,
KC-68 Stage 3 Turbo,
DashBoss/F/P, and a few other goodies
Stiction Problems - Fix it yourself! - http://www.powerstroke.org/forum/gen...ml#post4509754
Want to modify your injectors DIY - http://www.powerstroke.org/forum/6-0...ger-flows.html

Working for Toys
twoicebergs is offline  
post #6 of 6 Old 03-20-2013, 02:38 PM Thread Starter
LBR
Powerstroke.org Rookie
 
Join Date: Apr 2012
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Thank You!
LBR is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome