Fuel Pressure Of FASS After You Turn The Key Off
12-01-2007, 02:05 PM
#1
Registered User
Thread Starter
Join Date: May 2007
Location: Dallas, TX
Posts: 936
Likes: 0
Received 0 Likes
on
0 Posts
Fuel Pressure Of FASS After You Turn The Key Off
What is your fuel pressure after you turn your key off? I installed a FASS and it holds pressure steady at 15 until i turn off the key and immediately I get 1psi on the edge? The truck is also hard to start and I have no fuel leaks at all.
12-01-2007, 02:17 PM
#2
Registered User
Join Date: Apr 2007
Location: UT
Posts: 268
Likes: 0
Received 0 Likes
on
0 Posts
If you go to bluechips website they explain this phenomenon. The VP-44 can be damaged if ever fuel pressure has dipped below 6 psi. Usually when a better efficiency transfer pump is installed and if the vp-44 has been previously damaged, this is the complaint. Not saying this is your problem, but it sounds similar.
12-01-2007, 02:57 PM
#3
Registered User
Thread Starter
Join Date: May 2007
Location: Dallas, TX
Posts: 936
Likes: 0
Received 0 Likes
on
0 Posts
Are you talking about this http://www.bluechipdiesel.com/vp44diagnostichelp.html
I dont have dead pedal or any codes on the key off on trick.
Maybe its on its way out?
This sounds like my problem right here
I dont think the VP44 is bad but the electronics for the VP44 is not synced with the new FASS pressure?
I dont have dead pedal or any codes on the key off on trick.
Maybe its on its way out?
This sounds like my problem right here
Other complaints with the VP44 trucks are hard start hot and or hard start cold. If either of these problems are immediately followed by rough running that clears up in 5 seconds or so, look for a fuel delivery problem, such as fuel drainback or air getting into the fuel supply line. If you have rough running briefly after start you probably do NOT have an injection pump issue. If the truck runs instantly perfectly when it finally starts or shows white smoke on start up, your problem is the computer on the top of the injection pump. This component cannot be replaced in the field as it has to be programmed and calibrated to the mechanical part of the VP44. You have to buy a replacement pump to correct this problem.
I dont think the VP44 is bad but the electronics for the VP44 is not synced with the new FASS pressure?
12-01-2007, 03:05 PM
#4
Registered User
Join Date: Apr 2007
Location: UT
Posts: 268
Likes: 0
Received 0 Likes
on
0 Posts
I can't quite remember now where I read it, but somewhere maybe even in the FASS install manual, they talk about a damaged diaphram in the VP-44 from too low transfer pump pressure. They then go on to explain that once a good transfer pump is put in like a FASS pump, then the user may experience hard starting.
12-01-2007, 03:29 PM
#5
Registered User
Thread Starter
Join Date: May 2007
Location: Dallas, TX
Posts: 936
Likes: 0
Received 0 Likes
on
0 Posts
My pressure never fell below 15 with the lift pump. Allthough I did turn it over a few times with no fuel while the FASS primed. I just replaced it cause when it got cold it developed a small leak. I guess il just live with the hard starting for now.
12-01-2007, 04:58 PM
#6
Registered User
Join Date: Aug 2005
Location: Airdrie, Alberta
Posts: 7,780
Likes: 0
Received 0 Likes
on
0 Posts
I can't quite remember now where I read it, but somewhere maybe even in the FASS install manual, they talk about a damaged diaphram in the VP-44 from too low transfer pump pressure. They then go on to explain that once a good transfer pump is put in like a FASS pump, then the user may experience hard starting.
Thread
Thread Starter
Forum
Replies
Last Post
Tedonlin150
3rd Gen Engine and Drivetrain -> 2003-2007
2
06-21-2010 03:37 PM
Flyinhigh79
3rd Generation Ram - Non Drivetrain - All Years
3
05-14-2010 09:36 PM