How to check fuel pressure on a 12 valve - Dodge Cummins Diesel Forum
94-98 Engine Tech articles dealing with the 2nd gen 12V engine

 1Likes
  • 1 Post By illflem
 
LinkBack Thread Tools
Old 04-03-2009, 02:15 PM Thread Starter
Diesel Head
 
Join Date: Nov 2005
Location: Montana
Posts: 16,224
Thanks: 27
Thanked 2,314 Times in 1,609 Posts
iTrader Score: 0 reviews
How to check fuel pressure on a 12 valve

Drill and tap the top of the injection pump banjo bolt to 1/8'' pipe
thread, then install a male x female 1/8'' needle valve with 1/8'' tubing
compression fitting in it. Boost gauge or oil pressure tubing pushed
though some 1/4'' tubing to protect against cuts and kinks to the gauge.
For a 12 valve the gauge must be at least 40 psi, 60 psi is best. The gauge can say boost, air, water, fuel or nothing on it,
they will all work excellent.

Use no Teflon tape, it doesn't work with diesel.
Instead use anti-seize or Permatex #2. Remember you are
working on the clean side of the filter, keep everything spotless.
Compression fittings with a ferrule that slips over the tubing will leak
if overtightened, finger tight with one half turn of a wrench is plenty.
The ferrule should be replaced if the fitting is ever removed.

If you can tap your manifold for a pyro tapping the banjo bolt is a piece
of cake. Just drill from the inside to keep the hole straight and tap from
the outside.

You can also connect to the bleed screw on top of your fuel
filter with the appropriate adapter to tubing if you don't want to tap.
The adapter is available from TST for $25 they say it is for temporary use only Fuel Pressure Adapter .
I can see why it's not for permanent use, seems like the small bolt would break easily from engine vibration.
on edit, the adapter is no longer available.

After the install start your
engine with the needle valve closed then open it slowly till someone in
the cab signals you that it's just reading pressure. If you tighten down
the packing nut under the valve handle the setting can't move. The valve
will control pulsation and buzzing and can also be shut down in the
unlikely event that you have a leak. Without a valve to restrict the flow
the gauge will pulsate so badly that you won't be able to read it in the
short time before it self destructs. You can also use a gauge snubber http://www.dfs-gauges-blog.com/index...to-choose-one/
Cummins' pressure specs are 17-22 psi at idle, 25-35 at 2500 rpm no load,
Pressure should never drop below 15 psi under load for extended periods.


Parts list; 1/8'' needle valve - $2.50 from the hardware store, plastic
oil pressure tubing kit that comes with the compression fittings - under $10
from any auto parts store. 1/4'' tubing for protective sleeve - less than $2.
Gauge is your choice and may come with tubing. The pressure gauges I
use cost around $10 from here Surplus Center
Check back if you don't see a gauge you like, their stock changes weekly.
From Grainger, needle valve Valve, Needle, 1/8 In

Diagnosing problems using your fuel pressure gauge> Low Pressure Fuel System Diagnostic Procedures

It won't cost you much at all for a gauge that besides keeping you from walking
will eliminate unnecessary fuel filter changes, paying for itself rapidly.
I can usually go at least 30k between changes.

New, if you don't want to tap your banjo get one here> Larryb - LarryB's Gauge Snubber / Drilled 12mm Banjo Bolt Combo
you should still install a needle valve though, they don't always snub the pressure spikes enough plus you can't turn them off in the event of a leak
.

Larry B's pre-tapped banjo bolt




Needle Valve Installed On Tapped Injection Pump Banjo Bolt



__________________

imadieselnoob likes this.

Bill
'95 2500 4wd auto
'95 3500 5 speed heavy hauler
Stock for one day

Last edited by illflem; 12-12-2013 at 03:27 PM.
illflem is offline  
The Following 74 Users Say Thank You to illflem For This Useful Post:
'89dodge (05-05-2012), 12V4LIFE (08-03-2009), 12v_CTD (01-31-2013), 1997whitefozo (05-11-2010), 4btyjjeep (03-24-2012), 6BTpwr (11-26-2011), 7.3 4x4 power (03-11-2010), 9712valve (10-21-2009), Abell (08-26-2015), Apmcrx (09-12-2010), APWCU (11-30-2009), BennyBlaze (08-19-2012), BobCat357 (01-14-2014), bthomas125 (04-03-2014), Buckley Bubba (06-15-2013), BustedCrank (09-15-2012), camojcory (09-29-2012), CHEVYCUMMINS19855 (02-11-2013), CThurst_On (07-31-2016), CTK30 (12-10-2010), Cumminsdodge96 (10-26-2014), cumminsfarming (02-25-2014), D-Rex (08-01-2014), dcianfarini (02-28-2011), deerefanatic (03-13-2010), diggerphd (12-08-2009), DodgeMech (05-21-2010), DrinkMe (03-08-2012), dynodave1 (07-28-2015), gpmiller (01-04-2013), graytrain (06-26-2017), Greenlee (08-05-2015), gwb1340 (01-31-2012), happy camper (06-07-2012), hevyevie (12-02-2010), hiOsilver (09-05-2014), hippytrip (11-06-2019), honestcharlie56 (11-16-2011), J.R.R. (08-18-2019), jcw74801 (11-24-2009), JH96 (01-05-2012), jmstrickland (03-10-2011), k2climber02 (03-24-2011), Kickaha (11-13-2009), kraut (03-26-2011), Kyle95 (11-25-2012), LIL JOSE MIAMI (06-20-2013), Logan88 (07-23-2014), m715 (02-26-2014), Mendomotox (10-29-2014), michael_d (05-19-2014), mkwelds (10-26-2011), mnelson6688 (01-22-2014), Nater Tater (04-02-2013), nicebox77 (09-04-2012), owens1369 (09-17-2011), Ozzburner (08-29-2018), rabiddan1 (06-19-2013), rebar (07-29-2018), Rogan (10-26-2009), samuelscreech (10-26-2013), slakr600cc (06-28-2011), Smigjo (02-24-2012), Smoken Gun (11-06-2010), sn0man (02-07-2013), Sour-Diesel (11-07-2013), steelheadguy (01-10-2016), TaiNo- (05-13-2012), The_Hammer (10-31-2015), tmstim (07-25-2010), TurboSouthAfrican (12-04-2017), v10to12v (06-24-2010), windage (06-27-2015), XECCLLC (11-17-2010)
Sponsored Links
Advertisement
 
Old 04-03-2009, 02:16 PM
Only in a HEMI
 
BBRam's Avatar
 
Join Date: Jan 2006
Location: Chelsea MI
Posts: 27,656
Thanks: 1,811
Thanked 1,515 Times in 1,055 Posts
iTrader Score: 13 reviews
Thank you Bill !!!!!!!!!!!!!!



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

2012 Ram 2500 5.7L HEMI
2012 Dodge Challenger SRT8 6.4L HEMI
2015 Hellcat, and ya, it's got a HEMI
BBRam is offline  
The Following User Says Thank You to BBRam For This Useful Post:
johnecash (12-24-2014)
Sponsored Links
Advertisement
 
 

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Dodge Cummins 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









Thread Tools



Posting Rules  
You may not 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