Honda Fit Forums  

Go Back   Honda Fit Forums > Fit Forums > Engine

Engine Anything engine related post here. Repair, Maintenance, Mods, Swaps

Reply
 
Thread Tools Display Modes
  #1  
Old 09-27-2017, 10:59 PM
makikulit makikulit is offline
Junior Member
 
Join Date: Jul 2014
Posts: 6
makikulit is on a distinguished road
Default odb2 reading intake manifold pressure?

Claymore, just a quick question i've been tinkering with this odb2 elm327 scanner and what catches my attention is the intake manifold pressure mine goes around 4-5psi idle to 15psi at hway driving are these good values? BTW I'm driving a GD1 Thanks again...
Reply With Quote
  #2  
Old 09-28-2017, 01:27 PM
claymore's Avatar
claymore claymore is offline
Administrator
 
Join Date: Apr 2009
Location: Far side of the moon
Posts: 3,568
claymore is on a distinguished road
Default

Really can't help with this one right now. I will try and research it tomorrow.
__________________
Reply With Quote
  #3  
Old 09-29-2017, 08:56 PM
claymore's Avatar
claymore claymore is offline
Administrator
 
Join Date: Apr 2009
Location: Far side of the moon
Posts: 3,568
claymore is on a distinguished road
Default

This was the only thing I could find it gives the correct values but you have to read the captions to find them.


photos work in IE but not Firefox

http://www.hondafitjazz.com/manual/A...031FAAT00.HTML
__________________
Reply With Quote
  #4  
Old 10-03-2017, 05:02 AM
makikulit makikulit is offline
Junior Member
 
Join Date: Jul 2014
Posts: 6
makikulit is on a distinguished road
Default

hmmm i'll try that procedure next week, nevertheless i also ask my friends with scanners to perform the similar checks and looks like 3 of us got really close readings so i think my intake is ok.

thanks for your time Claymore...
Reply With Quote
  #5  
Old 10-05-2017, 02:16 AM
macbuddy's Avatar
macbuddy macbuddy is offline
Senior Member
 
Join Date: Jun 2009
Location: Central Valley, CA
Posts: 545
macbuddy will become famous soon enoughmacbuddy will become famous soon enough
Default As this was explained to me...

Quote:
Originally Posted by makikulit View Post
Claymore, just a quick question i've been tinkering with this odb2 elm327 scanner and what catches my attention is the intake manifold pressure mine goes around 4-5psi idle to 15psi at hway driving are these good values? BTW I'm driving a GD1 Thanks again...
makikulit, I monitor my MAP on a Scangauge2. My unit typically reads 5.7psi at idle, and also about 15 psi at freeway speeds. This would be about the right values for normally aspirated engines.
A tuner explained this to me about 2 months ago. IIRC, 14.7psi is one atmosphere. You would need forced injection in order to exceed 14.7 psi. For example, if you you were Turbocharged, and your gauge showed say 22.9 psi, then you would be running 8.2 lbs of boost.

22.9 psi -14.7 psi = 8.2 psi

If you are normally aspirated, then I am thinking that your gauge is rounding off to the next highest whole number, showing 15 psi rather than 14.7 psi. If you are force injected, then you are producing 0.3 lbs of boost.
Reply With Quote
  #6  
Old 10-10-2017, 03:19 AM
makikulit makikulit is offline
Junior Member
 
Join Date: Jul 2014
Posts: 6
makikulit is on a distinguished road
Default

Thanks MacBuddy for the info, I'm just running stock :-) it's good to know that you verified our findings. Could this baseline 4-5psi be used to check if there are leaks in the system intake given that the car is at sea level?
Reply With Quote
  #7  
Old 11-09-2017, 11:55 PM
macbuddy's Avatar
macbuddy macbuddy is offline
Senior Member
 
Join Date: Jun 2009
Location: Central Valley, CA
Posts: 545
macbuddy will become famous soon enoughmacbuddy will become famous soon enough
Default For the record...

Looking back at your original post, you state 4-5 lbs at idle. I told you that mine recorded 5.7 lbs at idle. I should add that my 5.7 lb value was taken while my 5AT was idling in gear. When I put the transmission into neutral, the psi drops to 4.5 lbs.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -7. The time now is 06:30 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.