Notices
ECU Flash

fuel pump low/high voltage transition table

Old Jul 30, 2014, 12:08 PM
  #61  
Evolving Member
iTrader: (3)
 
criptballer's Avatar
 
Join Date: May 2008
Location: Utah
Posts: 472
Likes: 0
Received 0 Likes on 0 Posts
ok, i'll assume that all tephra roms inherit from their corresponding numerical roms.

back to the other question, is there a thread that compiles all the tables not included in V7 that we need to add manually?
Old Sep 28, 2014, 10:58 AM
  #62  
Evolving Member
 
SiriusEvo's Avatar
 
Join Date: Dec 2013
Location: D
Posts: 195
Received 4 Likes on 3 Posts
What are you guys using for the high voltage transition hysteresis?

Last edited by SiriusEvo; Sep 28, 2014 at 11:53 AM.
Old Sep 28, 2014, 11:56 AM
  #63  
EvoM Guru
Thread Starter
iTrader: (50)
 
mrfred's Avatar
 
Join Date: Mar 2006
Location: Tri-Cities, WA // Portland, OR
Posts: 9,675
Received 128 Likes on 96 Posts
Originally Posted by SiriusEvo
What are you guys using for the high voltage transition hysteresis?
I left mine at 5 load units.
Old Feb 25, 2015, 05:38 PM
  #64  
Evolving Member
iTrader: (2)
 
AlphaKennyBody's Avatar
 
Join Date: Jul 2008
Location: Westside Cali
Posts: 376
Likes: 0
Received 0 Likes on 0 Posts
MrFRED,

Do you have something like this for the Evo X? I remember seeing it somewhere but I can't find it anywhere.
Old Feb 25, 2015, 05:59 PM
  #65  
EvoM Guru
Thread Starter
iTrader: (50)
 
mrfred's Avatar
 
Join Date: Mar 2006
Location: Tri-Cities, WA // Portland, OR
Posts: 9,675
Received 128 Likes on 96 Posts
Originally Posted by AlphaKennyBody
MrFRED,

Do you have something like this for the Evo X? I remember seeing it somewhere but I can't find it anywhere.
Yep, done for the Evo 10. I thought I created a thread in the Evo 10 ECUFlash forum.
Old Feb 26, 2015, 11:06 AM
  #66  
Evolving Member
iTrader: (2)
 
AlphaKennyBody's Avatar
 
Join Date: Jul 2008
Location: Westside Cali
Posts: 376
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by mrfred
Yep, done for the Evo 10. I thought I created a thread in the Evo 10 ECUFlash forum.
Hmmm I'll look but just in case link me =)
Old Feb 26, 2015, 02:58 PM
  #67  
EvoM Guru
Thread Starter
iTrader: (50)
 
mrfred's Avatar
 
Join Date: Mar 2006
Location: Tri-Cities, WA // Portland, OR
Posts: 9,675
Received 128 Likes on 96 Posts
I could swear that I wrote an Evo 10-specific thread, but I can't find anything. Sorry. Have you looked at Golden's definitions. He's usually on top of porting all these things to the Evo 10.
Old Feb 26, 2015, 04:00 PM
  #68  
Evolving Member
iTrader: (2)
 
AlphaKennyBody's Avatar
 
Join Date: Jul 2008
Location: Westside Cali
Posts: 376
Likes: 0
Received 0 Likes on 0 Posts
Damn... I remember seeing it somewhere be it that it's this site or another but I can't seem to find it.

I'll try to get with Golden and See what I can find. Thanks!!!
Old Feb 29, 2016, 08:01 PM
  #69  
EvoM Guru
iTrader: (8)
 
RazorLab's Avatar
 
Join Date: Aug 2003
Location: Mid-Hudson, NY
Posts: 14,065
Received 1,038 Likes on 760 Posts
All the first post code snippets are messed up still in this thread....

anybody have the def for 94170015?

Last edited by razorlab; Feb 29, 2016 at 08:43 PM.
Old May 21, 2016, 12:17 AM
  #70  
Evolved Member
iTrader: (4)
 
Raceghost's Avatar
 
Join Date: Dec 2001
Location: Out West
Posts: 1,034
Received 21 Likes on 21 Posts
All the first post code snippets are messed up still in this thread....

anybody have the def for 94170015?
Looking for these also. Specifically the startup timers the 03whitegsr speaks about. Can anyone point us to these table addresses, or the thread with them in it please? Thank you in advance.
Old May 21, 2016, 07:45 PM
  #71  
EvoM Guru
Thread Starter
iTrader: (50)
 
mrfred's Avatar
 
Join Date: Mar 2006
Location: Tri-Cities, WA // Portland, OR
Posts: 9,675
Received 128 Likes on 96 Posts
Originally Posted by Raceghost
Looking for these also. Specifically the startup timers the 03whitegsr speaks about. Can anyone point us to these table addresses, or the thread with them in it please? Thank you in advance.
Those tables won't help you. The timer causes the car to go pig rich for 30 seconds or something like that if IAT is over something like 150F when the car is started.
Old May 26, 2016, 12:09 AM
  #72  
Evolving Member
iTrader: (2)
 
ace33joe's Avatar
 
Join Date: Mar 2003
Location: Used to be in Nor Cal, now working in Seoul
Posts: 394
Received 7 Likes on 7 Posts
Originally Posted by razorlab
All the first post code snippets are messed up still in this thread....

anybody have the def for 94170015?
<table name="Min Load for Fuel Pump High Voltage" category="Fuel" address="4556" type="2D" level="1" scaling="Load8">
<table name="Engine Speed" address="642e" type="Y Axis" elements="10" scaling="RPM"/>
</table>

<table name="Low/High Voltage Transition Hysteresis" category="Fuel" address="1a74" type="1D" level="1" scaling="Load16"/>
Old Jun 2, 2016, 09:46 PM
  #73  
Evolved Member
iTrader: (4)
 
Raceghost's Avatar
 
Join Date: Dec 2001
Location: Out West
Posts: 1,034
Received 21 Likes on 21 Posts
Bump for Question. COuld not find answer anywhere.

What are the low fuel pressure actual numbers in PSI?

What are the high fuel pressure actual numbers in PSI?

I am interested, for I just did an upgraded FPR with gauge. At Idle, what should low pressure read?

Thanks in advance.
Old Jun 2, 2016, 10:18 PM
  #74  
Evolving Member
iTrader: (2)
 
ace33joe's Avatar
 
Join Date: Mar 2003
Location: Used to be in Nor Cal, now working in Seoul
Posts: 394
Received 7 Likes on 7 Posts
Originally Posted by Raceghost
Bump for Question. COuld not find answer anywhere.

What are the low fuel pressure actual numbers in PSI?

What are the high fuel pressure actual numbers in PSI?

I am interested, for I just did an upgraded FPR with gauge. At Idle, what should low pressure read?

Thanks in advance.
This table defines Low/high input voltage transition to fuel pump, and it does not necessarily meaning fuel pressure change.

Ideally, relative fuel pressure (pressure difference between injector input and output) should remain 3 bar (if stock regulator is used).

At idle, since intake manifold is in vacuum, the fuel pressure should be set to 3 bar minus whatever the vacuum gauge reads. For example, if the vacuum is 0.7 bar, the fuel pressure should be 2.3 bar.

Another way is to remove the vacuum hose to FPR and set the fuel pressure to 3 bar (if the atmospheric pressure stays relatively constant).

The reason why Mitsubishi put this low/high transition table is to reduce noise and extend lifetime of fuel pump for vacuum / low boost condition where most pumped fuel is returned to fuel tank anyway,

and I think the biggest reason why we still want to touch this table is that due to restrictive stock fuel return line (the first bottleneck is actually the small orifice at the pump housing), high flow fuel pump can give overly rich condition during boost transition.
Old Jun 3, 2016, 07:16 AM
  #75  
EvoM Guru
Thread Starter
iTrader: (50)
 
mrfred's Avatar
 
Join Date: Mar 2006
Location: Tri-Cities, WA // Portland, OR
Posts: 9,675
Received 128 Likes on 96 Posts
Originally Posted by ace33joe
This table defines Low/high input voltage transition to fuel pump, and it does not necessarily meaning fuel pressure change.

Ideally, relative fuel pressure (pressure difference between injector input and output) should remain 3 bar (if stock regulator is used).

At idle, since intake manifold is in vacuum, the fuel pressure should be set to 3 bar minus whatever the vacuum gauge reads. For example, if the vacuum is 0.7 bar, the fuel pressure should be 2.3 bar.

Another way is to remove the vacuum hose to FPR and set the fuel pressure to 3 bar (if the atmospheric pressure stays relatively constant).

The reason why Mitsubishi put this low/high transition table is to reduce noise and extend lifetime of fuel pump for vacuum / low boost condition where most pumped fuel is returned to fuel tank anyway,

and I think the biggest reason why we still want to touch this table is that due to restrictive stock fuel return line (the first bottleneck is actually the small orifice at the pump housing), high flow fuel pump can give overly rich condition during boost transition.
Pretty close on most of this. I'll summarize as well: The 2-step voltage range is to prevent fuel pressure overrun under low fuel requirements, allows the pump to run cooler when high fuel flow is not needed, and it extends the life of the pump.

It is not used to set a particular fuel pressure. That job is handled entirely by the fuel pressure regulator as long as there is no overrun. Overrun occurs when fpr can't flow high enough to control fuel pressure. This would happen if the fuel pump were running at full voltage at idle and light throttle. It causes AFRs to become uncontrollably rich at idle and ligh cruise, and generally f's with the ability to control AFR. This happens to people who hardwire their fuel pumps (and thereby remove the factory capability to supply low/full voltage).

Raceghost - To answer your idle fuel pressure question, the standard fuel pressure at idle with the FPR vacuum line disconnected from the intake manifold is 43.5 psi. Don't try and set the fuel pressure with the vacuum line connected. I'll comment that the stock FPR is actually very good, and there is no need to upgrade unless you have a desire to run higher base fuel pressure than stock. For most people, there is no need to use anything other than the stock FPR.

Thread Tools
Search this Thread
Quick Reply: fuel pump low/high voltage transition table



All times are GMT -7. The time now is 07:14 AM.