Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > POWER TRAIN GARAGE FORUMS > Cummins Engines
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 06-28-2016, 11:43 AM   #1
Junior Member
 
Join Date: Dec 2012
Location: Hudson WI
Posts: 15
Fuel pressure gauge install on CAPS fuel system

I have a 2001 cummins ISC 330 engine that I want to put a fuel pressure gauge on,so I can monitor fuel pressure to the CAPS fuel pump.The directions with the gauge I have bought sayes to install sender on top of fuel filter or lift pump. So I installed on top of fuel filter but all I get is lift pump pressure at start up, then the pressure gauge goes to zero. I have researched and haven't been able to find a place to install the sending unit on the CAPS pump to register fuel pressure at all time when running. Any help would be appreciated.
__________________
ldrvers
2001 Monaco Diplomat LE 330 Cummins
2006 Saturn VUE (toad)
ldrvers is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-28-2016, 03:06 PM   #2
Senior Member
 
Dtwallace's Avatar
 
Join Date: May 2014
Posts: 1,368
I have to ask,


You do understand you are working with two fuel pressure systems?


The one you've taped into is the low pressure side/lift pump from tank.


As I read your question, I'm assuming the kit, based on the instructions are for the low pressure side only. That's pressure that is below 100PSI.


Your high pressure side of this fuel system can reach pressures into the thousands.
I don't have the exact specifications in front of me as I'm responding here but I would assume yours approaching the 3K area minimum, 44K max to the injectors.


Is the gauge you are using rated for that high of pressure? If not, please be careful, you are about to make a mistake that could cause you injury.


DTW
__________________
Dan & Loretta, US Army Retired Aero Scout Pilot
2012 Fleetwood Providence 42P Class A/DP
Spartan Chassis, 8.9L Cummins 450HP
Dtwallace is offline   Reply With Quote
Old 06-28-2016, 08:02 PM   #3
TR4
Senior Member
 
TR4's Avatar
 
Join Date: May 2016
Location: St. Maries, Idaho
Posts: 959
On the CAPS system you will only have fuel pressure while the lift pump primes the lines after the lift pump. After prime the gear pump on the CAPS pulls the fuel through the filters, lift pump manifold and fuel lines. So when the filters are dirty the CAPS gear pump is working hard to supply fuel to the accumulator and injectors. This is a known problem with the CAPS.
After reading Smitty's posts regarding these problems, I chose to replace the lift pump as he did. I installed a Fass aftermarket fuel pump from Brazel's. I also installed a Isspro EV2 fuel gauge. The sending unit is installed to the top of the secondary fuel filter. The fuel pump runs when ever the ignition is on supplying 15# fuel pressure to the CAPS. Now when the filters start to ge dirty I can see pressure dropping. I also run OptiLube for lubrication of the CAPS.

Bill
__________________
2003 Country Coach Intrigue 36'
Cummins ISL 400
TR4 is online now   Reply With Quote
Old 06-29-2016, 01:27 PM   #4
Senior Member
 
Spartan Chassis
Join Date: Aug 2015
Location: SW, MO
Posts: 162
just a bit more info

I also re-pumped my CAPS system. After a failure in my 2002 Dodge truck with the same system I highly recommend this. If the high pressure pump is starved for fuel for any reason it will be damaged. The cost of replacement pump in this system is in the 1000s of dollars on a motorhome. Pump alone is more than $1000. Labor can be as high as $3000. I now have a Fass system with water separator and a 2 micron filter which is running whenever the key is in the "on". This system costs less installed than a HP pump alone would cost on the road. I keep spare filters with me. If I fill up my fuel and lose power or my pressure drops it is usually a sign of bad tank of fuel. Check your water separator daily when traveling. A small container placed under the filter to catch what you drain out and you can see if there is water in your fuel.
Hopefully this will help you. It is a good system if managed properly.


Good Luck & Happy Motoring
Don
__________________
Happy Motoring
Don Susan
2000 Newmar DSDP 3894, Cummins 330, Spartan, MM,
2004 Pilot toad
4Fingers is offline   Reply With Quote
Old 07-05-2016, 02:41 PM   #5
Senior Member
 
Coma's Avatar
 
Monaco Owners Club
Join Date: Nov 2010
Location: The Emerald Coast
Posts: 1,759
Quote:
Originally Posted by ldrvers View Post
I have a 2001 cummins ISC 330 engine that I want to put a fuel pressure gauge on,so I can monitor fuel pressure to the CAPS fuel pump.The directions with the gauge I have bought sayes to install sender on top of fuel filter or lift pump. So I installed on top of fuel filter but all I get is lift pump pressure at start up, then the pressure gauge goes to zero. I have researched and haven't been able to find a place to install the sending unit on the CAPS pump to register fuel pressure at all time when running. Any help would be appreciated.
There is a negative pressure across a filter, that is, a drop in pressure relative to the in side.

There is a lot of info here.
__________________
Jim and Jennie, Cats=Bittles and Potter, 2000 Dynasty 350 ISC
2013 Silverado 4x4 Towed with R1200GS in bed.
PROV23:4 Do not wear yourself out to get rich; have the wisdom to show restraint.
Coma is offline   Reply With Quote
Old 07-10-2016, 01:46 PM   #6
Junior Member
 
Join Date: Dec 2012
Location: Hudson WI
Posts: 15
Thanks for the reply, sorry for the untimely response.
DTW
Yes i do understand there is two systems. I wanted to monitor the pressure between the mechanical pump and the accumulator. I under stand that if the pump never gets low fuel pressure and is well lubricated it will last a long time. My fuel gauge is a 30 psi gauge,and thats all I should need.
Bill
I'm very interested in your post. Did your pump mount in the factory location? What pump did you get? How did you wire the pump to run all the time? How did you come up with 15psi.

I replaced my lift pump last year (preventave maintance) but I'm not really happy with that system. I think there is better more dependable way.
I had my CAPS pump replaced two years ago $5200.00,I don't want to do that again.

Thanks for your response all comments.
Ldrvers
__________________
ldrvers
2001 Monaco Diplomat LE 330 Cummins
2006 Saturn VUE (toad)
ldrvers is offline   Reply With Quote
Old 07-10-2016, 07:49 PM   #7
Senior Member
 
Join Date: Aug 2002
Location: Where ever I park it
Posts: 1,345
The overflow valve on the return line where it comes out of the pump has a spring and a ball in it. It acts as a check valve and also a pressure regulating valve that takes 14 psi give or take to open. If you can supply enough fuel pressure to open that valve you are supplying enough fuel to cool and lube the pump.
__________________
2005 Dodge Ram Four Door Dually Southern Comfort Conversion
2017 Forest River 365RK
MnTom is offline   Reply With Quote
Old 07-10-2016, 09:01 PM   #8
TR4
Senior Member
 
TR4's Avatar
 
Join Date: May 2016
Location: St. Maries, Idaho
Posts: 959
Ldrvers,
I got the idea for my install from Smitty (he has a lot of posts on this forum).
He had his install done by Brazel's RV in Washington. I called the and spoke with Alan, telling him I wanted the same Fass pump that he installed for Smitty. He sent it out and I had it in two days. He told me to call him if I had any questions on the install. There were hoses and fittings I didn't use that came with the kit but overall everything but the hoses were included.

On my coach the primary and secondary filters are located in the rear passenger compartment. The lift pump pulls the fuel from the tank through the primary filter to the lift pump manifold. It then pushes the fuel out through the secondary filter into the CAPS gear pump. That's why you show fuel pressure only while the lift pump primes the fuel lines, it will then turn to a vacuum as the gear pump is pulling fuel through the lines and filters.

I as well as Smitty left the old lift pump in place and just bypassed it. It can easily be rehooked up if needed.

This is how I did it.
Fuel line from tank to primary filter is left in place.
Fuel line from primary filter to lift pump is disconnected at the primary filter and capped.
Fuel line from the lift pump to the secondary filter is disconnected at the secondary filter and capped.
Fuel line from the secondary filter to the CAPS is left in place.
Now you have a primary filter with the output port open (no line connected).
You have a secondary filter with the input port open (no line connected).
Now you install the Fass pump. These next two fuel lines will have to be made up. I used Products & Services - PIRTEK USA
Hose out of primary filter into Fass in port.
Hose out of Fass pump into secondary filter.

Pirtek had all the fittings for the hose to pump, on mine they're 5/8". I wanted to use the same size fittings so if need be I could just reconnect the lines from the stock lift pump to the filters.

For power you need 12 volts. Right next to the pump there's a fuse box. Run a fused line out to a relay.
Now you need a 12volt signal for the relay from something that's on when the ignition is on. Some people use the fan controller circuit for this signal, but I don't know if you have this.
I used the circuit for my school bus pump (the one that always fails). I removed my school bus pump so I had a 20 amp circuit available. Since it was a 20 amp line, I didn't need a relay.

Last you need to fool the ECM into thinking the lift pump is still connected. You take the relay and lift pump connector supplied in the kit and connect the line from the lift pump to the new connector. The load from the relay fools the ECM into think the pump is still there.

If you buy the Fass pump from Brazel's, Alan will give you the connector numbers on the relay.

I then installed a Isspro fuel pressure gauge to the port on the top of secondary filter. The Fass pump comes stock from the factory at about 17 psi (it's adjustable).

If you get a lot of movement in the gauge needle you'll have to install this;
Fuel Pressure Gauge trashed...

Bill
Attached Thumbnails
Click image for larger version

Name:	image.jpg
Views:	678
Size:	248.3 KB
ID:	132675  
__________________
2003 Country Coach Intrigue 36'
Cummins ISL 400
TR4 is online now   Reply With Quote
Old 07-12-2016, 09:26 AM   #9
Senior Member
 
Smitty77's Avatar
 
Join Date: Aug 2010
Location: Over the next hill, around the next curve...
Posts: 5,659
http://www.irv2.com/forums/f123/isl3...mp-265692.html


Here is my post on the swap out.

Like the install TR4, and will add the pressure gauge as more info to confuse the DW with when she drives!

As mentioned in other threads, this was more of an insurance then necessity modification. And, as I still have not given up on adding a bit more performance out of the ISL370(400) - I wanted to be sure we never starved that expensive CAPS!

That being said, millions of miles are on the ISC/ISL CAPS engines, with the Lift Pump just getting things started, and the CAPS doing the lifting (sucking) to go down the road...

Each much do what they feel is appropriate for them. We're keeping this coach for about 10 years of usage, so I always look at modifications based upon that pay back period of usage.

Travel safe, have fun,
Smitty
__________________
07 Country Coach Magna Rembrandt 45' ISX600
Roo II was our 04 Country Coach Allure 40'
OnDRoad for The JRNY! Enjoy life...
Smitty77 is offline   Reply With Quote
Old 07-12-2016, 08:11 PM   #10
TR4
Senior Member
 
TR4's Avatar
 
Join Date: May 2016
Location: St. Maries, Idaho
Posts: 959
Quote:
Originally Posted by Smitty77 View Post
http://www.irv2.com/forums/f123/isl3...mp-265692.html


Here is my post on the swap out.

Like the install TR4, and will add the pressure gauge as more info to confuse the DW with when she drives!

As mentioned in other threads, this was more of an insurance then necessity modification. And, as I still have not given up on adding a bit more performance out of the ISL370(400) - I wanted to be sure we never starved that expensive CAPS!

That being said, millions of miles are on the ISC/ISL CAPS engines, with the Lift Pump just getting things started, and the CAPS doing the lifting (sucking) to go down the road...

Each much do what they feel is appropriate for them. We're keeping this coach for about 10 years of usage, so I always look at modifications based upon that pay back period of usage.

Travel safe, have fun,
Smitty
Smitty, I could have saved a lot of writing! Thanks for all your posts.

Bill
__________________
2003 Country Coach Intrigue 36'
Cummins ISL 400
TR4 is online now   Reply With Quote
Old 07-14-2016, 12:24 PM   #11
Senior Member
 
jleamo1's Avatar
 
Holiday Rambler Owners Club
Join Date: Apr 2016
Posts: 596
This is interesting, I was considering installing a Fass pump next to the fuel tank on my ISL to help push the fuel 40' back to the primary filter and just push it through the existing lift pump since it has a bypass on it shuts off. My concern was is; where does the excess fuel go if the CAPS pump isn't calling for that much, dead end? Now it routes back to the tank from the lift pump? My fuel tank is out in the open with a bunch of space all around it.
__________________
2002 Holiday Rambler Imperial 40PKD
with Residential refrigerator conversion
2014 Jeep Wrangler in tow, M&G brake system
jleamo1 is offline   Reply With Quote
Old 07-14-2016, 07:15 PM   #12
Senior Member
 
Join Date: Aug 2002
Location: Where ever I park it
Posts: 1,345
Normally the return is plumbed into the suction line just before the lift pump. If you want to put the extra pump by the tank you would need to run the return to the suction side of the new pump.
__________________
2005 Dodge Ram Four Door Dually Southern Comfort Conversion
2017 Forest River 365RK
MnTom is offline   Reply With Quote
Old 07-14-2016, 07:46 PM   #13
TR4
Senior Member
 
TR4's Avatar
 
Join Date: May 2016
Location: St. Maries, Idaho
Posts: 959
Quote:
Originally Posted by MnTom View Post
Normally the return is plumbed into the suction line just before the lift pump. If you want to put the extra pump by the tank you would need to run the return to the suction side of the new pump.
I may be wrong, but I thought the lift pump was mounted to the lift pump manifold. The manifold has two parts. One for the intake and output of the lift pump fuel. The other as an input and output from the CAPS and injector fuel returning to the tank.

I wouldn't put the pump at the tank unless you move the primary filter before it. You want the pump to run on filterd fuel.

If I'm wrong on this, someone please correct me.

Bill
__________________
2003 Country Coach Intrigue 36'
Cummins ISL 400
TR4 is online now   Reply With Quote
Old 07-15-2016, 05:03 AM   #14
Senior Member
 
jleamo1's Avatar
 
Holiday Rambler Owners Club
Join Date: Apr 2016
Posts: 596
Bill, I should have explained it better. I was going to install a 10 micron filter (spin on) between the tank and the pump, put both of them within 1' of the fuel tank pick up (plenty of room). I was thinking the pump would supply the Cummins fuel separator next (all the way in the back), onto the existing lift pump (which only runs for 30 seconds on start up then switches to bypass) on to the secondary Cummins filter then to the CAPS pump. My thoughts are....and I could be wrong the factory lift pump goes into bypass so the constant pressure from the Fass pump (set to 15psi) would just be like a booster for the existing system. Any thoughts on how the factory lift pump will react with positive pressure on its inlet side?
The reason for this is I do not wasn't to re-plumb the engine bay, my lift pump has several lines going to it (from memory I have the supply in, out and the tank return, plus 1 or 2 steel lines with banjo fittings). The Fass pump I was looking at is just an adjustable pump (not the kit with the filters).
__________________
2002 Holiday Rambler Imperial 40PKD
with Residential refrigerator conversion
2014 Jeep Wrangler in tow, M&G brake system
jleamo1 is offline   Reply With Quote
Reply

Tags
fuel, install



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

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Faulty Fuel Gauge.......is Scan Gauge a good alternative? DGBPokes Spartan Motorhome Chassis Forum 9 07-06-2015 08:43 PM
Fuel pressure gauge install- help ARFFMAN Ford Motorhome Chassis Forum 18 04-17-2015 06:58 PM
Low fuel pressure indicator, fuel pressure gauge or both? Zoafan Cummins Engines 4 02-13-2013 06:03 AM
Fuel Gauge & Volt Gauge not working Deerhunter Freightliner Motorhome Chassis Forum 9 07-20-2010 02:22 PM
temp gauge & fuel gauge indicators antlerz MH-General Discussions & Problems 9 02-16-2006 05:34 PM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 09:58 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.