Low fuel pressure and don’t know why - Kawasaki KFX450 Forum :: KFX450HQ.com
Engine/EFI/Drivetrain Discuss engine, fuel injection, air intake, and drivetrain modifications here.

 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 01-11-2019, 02:13 PM Thread Starter
Junior Member
 
Austin Jochum's Avatar
 
Join Date: Jan 2019
Posts: 3
View Austin Jochum's Photo Gallery(0)
Low fuel pressure and don’t know why

So as the title says I have low fuel pressure and no clue why. A little bit of history on the quad I got it knowing that it didn’t run right I went through checked I was getting fuel check that the injector was working checked the valve lash everything that you would think to check. ended up checking the fuel pressure it holds 43 PSI at idle but when revved drops to near zero and dies. So I got a new fuel pump from eBay put it in put the new filter and everything looked fine start up and same problem low fuel pressure when revved. Got to thinking and I thought it was the fuel pressure regulator so I went and got a fuel pressure regulator could only find them with the pump so got a Nother pump and fuel pressure regulator. Put it in everything worked fine let it idle and warm up then went to rabbit and it just died again been messing with this for about a month and a half now don’t know why scratching my head looking fo put it in everything worked fine let it idle and warm up then went to rabbit and it just died again been messing with this for about a month and have Gotten very frustrated with it. I don’t want to go and get a new $250 sending unit and am at a roads end any help is greatly appreciated
Austin Jochum is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 01-11-2019, 10:33 PM
Senior Member
 
blue99stroker's Avatar
 
Join Date: Jan 2014
Location: Northern California
Posts: 1,824
View blue99stroker's Photo Gallery(0)
The regulator is sealed with plastic cement if I remember right.

Also, the fuel pump relay could be failing not passing full power to the pump under load.

You might want a new sending unit.

08 KFX450r- DASA, FCI, Stage 2 Hotcams, Wiseco Programmer, Procom, Dynatek Coil, 6K HID, 7" LED Light Bar.

Race Tech dual rate front springs, GT thunder XC Link and Race tech spring

Poly Case Saver, Streamline Stabilizer, Full PRM Skidplates, Pro Armor Bumpers, Tusk Heel Guards, TRX Rear Hubs, IMS 3.7 tank
blue99stroker is offline  
post #3 of 7 (permalink) Old 01-13-2019, 08:10 PM
Super Moderator
Premium Member
 
Dust Devil's Avatar
 
Join Date: Oct 2009
Location: Lake Havasu city, Arizona
Posts: 9,413
View Dust Devil's Photo Gallery(0)
Have you checked your battery's charging system...!! see attachment below
Attached Thumbnails
Click image for larger version

Name:	Charging system.JPG
Views:	44
Size:	146.7 KB
ID:	24228  

Check with Site Sponsors "First"

(Immortal ATV)
Todd
http://immortalatv.com
1-(800)380-9646
[email protected]
Save 5% off $100 or more, use coupon code: KFX450HQ

(KB Motor-sports)
Website:
http://www.kbmotorsportsonline.com

(Discount Tire)
At The Store: www.discounttire.com
To Your Door: www.discounttiredirect.com
Sales and Technical: 1.888.459.4080




Dust Devil is offline  
Sponsored Links
Advertisement
 
post #4 of 7 (permalink) Old 01-17-2019, 10:35 AM Thread Starter
Junior Member
 
Austin Jochum's Avatar
 
Join Date: Jan 2019
Posts: 3
View Austin Jochum's Photo Gallery(0)
I’ve tried swapping some of the 4 relays that are all sitting there and changing them didn’t make a change

I’ll try testing the battery this weekend although I doubt it will get a bad reading because I’ve tried hooking up a battery charger to the battery while it’s running to make sure it wasn’t from low voltage yet the problem was not fixed

I’m trying to avoid getting the whole sending unit but if that’s what it comes to then so be it

Only reason I can think of needing to replace the sending unit is because the plastic is cracked
Austin Jochum is offline  
post #5 of 7 (permalink) Old 01-19-2019, 02:39 PM
Super Moderator
Premium Member
 
Dust Devil's Avatar
 
Join Date: Oct 2009
Location: Lake Havasu city, Arizona
Posts: 9,413
View Dust Devil's Photo Gallery(0)
Quote:
Originally Posted by Austin Jochum View Post
I’ve tried swapping some of the 4 relays that are all sitting there and changing them didn’t make a change

I’ll try testing the battery this weekend although I doubt it will get a bad reading because I’ve tried hooking up a battery charger to the battery while it’s running to make sure it wasn’t from low voltage yet the problem was not fixed

I’m trying to avoid getting the whole sending unit but if that’s what it comes to then so be it

Only reason I can think of needing to replace the sending unit is because the plastic is cracked
If the plastic is cracked, the regulator is bad or the o-rings around the regulator are bad or missing..then the fuel is recycled back into the tank..thus the loss of pressure...

Here's the cheapest sending unit I found on Ebay.. https://www.ebay.com/itm/08-14-KAWAS...k21:rk:26:pf:0

Check with Site Sponsors "First"

(Immortal ATV)
Todd
http://immortalatv.com
1-(800)380-9646
[email protected]
Save 5% off $100 or more, use coupon code: KFX450HQ

(KB Motor-sports)
Website:
http://www.kbmotorsportsonline.com

(Discount Tire)
At The Store: www.discounttire.com
To Your Door: www.discounttiredirect.com
Sales and Technical: 1.888.459.4080




Dust Devil is offline  
post #6 of 7 (permalink) Old 01-20-2019, 01:41 AM Thread Starter
Junior Member
 
Austin Jochum's Avatar
 
Join Date: Jan 2019
Posts: 3
View Austin Jochum's Photo Gallery(0)
I would agree however does not explain why it holds perfect pressure till revved that’s why I’m so confused on this problem
Austin Jochum is offline  
post #7 of 7 (permalink) Old 01-20-2019, 01:23 PM
Super Moderator
Premium Member
 
Dust Devil's Avatar
 
Join Date: Oct 2009
Location: Lake Havasu city, Arizona
Posts: 9,413
View Dust Devil's Photo Gallery(0)
Quote:
Originally Posted by Austin Jochum View Post
I would agree however does not explain why it holds perfect pressure till revved thatís why Iím so confused on this problem
When a fuel pump/regulator goes bad it's starts losing pressure around the higher RPMs (usually) causing lean fuel mixtures and gets worst from there...idle pressure usually remains good throughout the ordeal...!!

Check with Site Sponsors "First"

(Immortal ATV)
Todd
http://immortalatv.com
1-(800)380-9646
[email protected]
Save 5% off $100 or more, use coupon code: KFX450HQ

(KB Motor-sports)
Website:
http://www.kbmotorsportsonline.com

(Discount Tire)
At The Store: www.discounttire.com
To Your Door: www.discounttiredirect.com
Sales and Technical: 1.888.459.4080




Dust Devil is offline  
Reply

  Lower Navigation
Go Back   Kawasaki KFX450 Forum :: KFX450HQ.com > KFX450 Performance > Engine/EFI/Drivetrain

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki KFX450 Forum :: KFX450HQ.com 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











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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