Skip to main content ↑ ↓
Topic: Fuel System Science Project (Read 5035 times) previous topic - next topic

Re: Fuel System Science Project

Reply #40 –
What did you use for the insulation? It looks great!

Re: Fuel System Science Project

Reply #41 –
Quote from: krush –
What did you use for the insulation? It looks great!

It took about 2.5 rolls of this stuff-

Amazon.com: Thermo-Tec 14120 48" X 72" One Sided Thermo Guard Flame Retardant:

They make a version that has both sides aluminized but I'm not sure its needed but I know thats what Barry and Cindy used.  Amazon got my order mixed up and sent me one of each when I ordered it and I didn't feel like sending it back so I ended up using a mixture of both types.  There isn't any difference other than the one has two aluminum sides. 

If you install it with two people it would probably look a bit nicer and certainly be easier to hold in place while starting out.  The spray adhesive didn't provide enough initial grab to support the weight of the material so I was trying to put the screws in with one hand while holding the sheet up with the other. 
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Fuel System Science Project

Reply #42 –
So I'm midway through my trip to North Dakota and I figured I'd update this post with current numbers.

I've got the adjustable fuel pressure regulator at the highest value I can muster without removing the AC compressor bracket.  I'm currently still at ~24psi idle though I'm sure the pressure could be raised if the valve were removed and adjusted but I've been too busy with other things at the moment. 

Since installing the valve, I've also replaced the stock 4" exhaust system with a 5" Magnaflow Hushpower muffler and piping.  This has allowed me to be able to sustain long term boost pressures on hills of 24 psi and have occasionally hit 26.  The larger exhaust seems to take longer to get to 22+psi compared to the stock 4"  but has seen higher overall peak numbers though the higher numbers only really happened on longer hills than I ever tested the stock 4" setup on.    I recall somebody on here dyno'ed their rig with a C8.3 and found that the 4"  setup produced more power and torque. 

The downside to this extra boost is the fuel pressure at WOT drops to a low of 7-8 psi which is just below the 9 psi maximum value I had with the old, worn out original valve.  When I get around to removing the AC bracket, I'd like to end up with fuel pressure in the double digits and WOT.  Hopefully the valve has enough adjustment left in it to make that happen, I imagine idle will probably be around upper 20s for that.  In the meantime, this C8.3 is clearly moving much quicker than it did before the fuel pressure and exhaust system upgrades.  My dreams have been filled with Holset Super 40s and electric fuel pump upgrades lately.

I also haven't managed to kill myself by staring at the 3in1 gauge yet while driving, surprisingly. 

Re: Fuel System Science Project

Reply #43 –
We are back on our fuel project after a few months delay from traveling. I have re-read every Forum posting and checked out many links. We thank all who told their story and responded to our questions earlier this year. I have gleaned our needed parts from what others have used.

I think that making the step to an electric fuel lift pump at this time adds too many questions and may not be needed, so it is on hold.

Our Cummins C8.3 is running just fine, but we plan to install new preventative parts:

Injector pump input snubber - TorkTek CBS010 Injector pump output fuel return - TorkTek OFV020

mechanical lift/transfer pump - wonder if there are improved & recommended aftermarket brand lift pumps, instead of Cummins part, how is Allliant? Are all new lift pumps manufactured with rubber internal parts that can withstand BioDiesel?

Lift pump mounting studs - LarryB's Stud Mounting Kit

Jegs gauge damper hose kit p/n 41057 2nd snubber 1/8" male/female, assuming more snubbing is better for gauge sender.

Fuel Pressure Gauge:

We prefer a dash mounted electric digital fuel pressure gauge with high/low memory, but are not sure what gauge to buy.
I have looked at many gauge brands and find only Cyberdyne has high low memory, but it does not have good PSI ranges.
I do see other digital gauges without memory that look pretty good, like GlowShift MaxTow DoubleVision 0-30psi.

If anyone has put in an electric digital gauge, we would appreciate your experience and review.

Wow, can't believe we are getting ready to order parts as this has been a very large thoughtful project.

Thanks again. . .
Barry & Cindy

Re: Fuel System Science Project

Reply #44 –
Quote from: Barry & Cindy –
...aftermarket brand lift pumps, instead of Cummins part, how is Allliant?
Barry,

When I got ready to replace my lift pump, I emailed "LarryB" and asked about recommended brands.  He said they are all made in China now, even the replacements sold under the Cummins brand.  So basically, just take your pick.  I went with the ALLIANT-AP4988747, and the best price I found was at Thoroughbred Diesel, $84.16 with free shipping + they give you instant $5.00 off with your first order from them:

Alliant Power 5.9L Dodge Fuel System Components

I don't know about the BioDiesel compatability - only time will tell.  Installation was easy with the stud kit.  I did have to add a reducer bushing to the inlet port to adapt to my existing fuel line.  The pump has been working great - instant starts, smooth idle, good power, no leaks.

Re: Fuel System Science Project

Reply #45 –
Quote from: Barry & Cindy –
We are back on our fuel project after a few months delay from traveling. I have re-read every Forum posting and checked out many links. We thank all who told their story and responded to our questions earlier this year. I have gleaned our needed parts from what others have used.

I think that making the step to an electric fuel lift pump at this time adds too many questions and may not be needed, so it is on hold.

Our Cummins C8.3 is running just fine, but we plan to install new preventative parts:

Injector pump input snubber - TorkTek CBS010 Injector pump output fuel return - TorkTek OFV020

mechanical lift/transfer pump - wonder if there are improved & recommended aftermarket brand lift pumps, instead of Cummins part, how is Allliant? Are all new lift pumps manufactured with rubber internal parts that can withstand BioDiesel?

Lift pump mounting studs - LarryB's Stud Mounting Kit

Jegs gauge damper hose kit p/n 41057 2nd snubber 1/8" male/female, assuming more snubbing is better for gauge sender.

Fuel Pressure Gauge:

We prefer a dash mounted electric digital fuel pressure gauge with high/low memory, but are not sure what gauge to buy.
I have looked at many gauge brands and find only Cyberdyne has high low memory, but it does not have good PSI ranges.
I do see other digital gauges without memory that look pretty good, like GlowShift MaxTow DoubleVision 0-30psi.

If anyone has put in an electric digital gauge, we would appreciate your experience and review.

Wow, can't believe we are getting ready to order parts as this has been a very large thoughtful project.

Thanks again. . .
Barry & Cindy


I like the idea of leaving a fully functioning system alone..  pc

Re: Fuel System Science Project

Reply #46 –
Quote from: pocketchange –

I like the idea of leaving a fully functioning system alone..  pc

I agree. There are thousand upon thousands of these engines operating around the world and they seem to be doing fine with the stock components.

Re: Fuel System Science Project

Reply #47 –
Quote from: Barry & Cindy –
mechanical lift/transfer pump - wonder if there are improved & recommended aftermarket brand lift pumps, instead of Cummins part, how is Allliant? Are all new lift pumps manufactured with rubber internal parts that can withstand BioDiesel?

Lift pump mounting studs - LarryB's Stud Mounting Kit

I do see other digital gauges without memory that look pretty good, like GlowShift MaxTow DoubleVision 0-30psi.

If anyone has put in an electric digital gauge, we would appreciate your experience and review.

Are you sure that you need the stud kit?  My 98 already had the studs installed with the original lift pump.

As I've mentioned before, I've got the GlowShift 3in1 gauges.  I'm very happy with it and it allows fuel pressure readings up to 60psi.  After having the electric gauges, I wouldn't feel that it was necessary for the low/high memory since you are able to get consistently repeatable results.  There was really nothing to the install other than either running a few wires front to back or using the extra existing wires.  Just the snubber and an extra length of hose at the inlet to the injection pump with the sender attached to it and mounted higher than the injection pump to keep a pocket of air to dampen the pulses. 

No idea about the mechanical lift pump options, I'm using a new unit bought from Cummins. 

Re: Fuel System Science Project

Reply #48 –
 I hope I do not have to work on the lift pump on our coach as it sure is in a lousy location for people with back issues.
I do have a kit for it with the seal/etc that is good for ULS fuel as was able to get it from Cummins before they stopped selling them and having to buy whole pump.
JohnH

Re: Fuel System Science Project

Reply #49 –
Robert, great idea, I will look to see if we already have studs. I saw that you had the 3-in-1 gauge that you can't take your eyes off. Since we already have a boost gauge and a great unique pyrometer, I figure that a single gauge will do it and since I can't find any with memory, I have put my eye on the Glow Shift Max Tow 30psi electric fuel pressure gauge with digital readout and sweep hand. Thanks for the idea to mount sender higher than pump, as it makes sense.

John, our C8.3 has a different fuel pump than your ISC8.3, which had the gasket problem and ours is on the curbside. It is still difficult to reach pump, hope not worse than reaching the fuel shut off solenoid for replacement.

Thanks for the replies.

Re: Fuel System Science Project

Reply #50 –
call, had to have my high pressure pump rebuilt. They replaced duel shut off solenoid (FSS), fuel shut off valve, etc. While doing the job. I saw the replacement FSS identical to the new one in the picture. When we picked up our unit (1996 Cummins C8.3) I noticed the throttle "feel" had changed. It now feels like it is binding at initial foot pressure and then releasing making it very tough to control low speed action in tight places. I will get out to my up unit and see if the mechanic ignored the increased size of the new FSS and its effect on the adjacent throttle cable.

Re: Fuel System Science Project

Reply #51 –
Quote from: Barry & Cindy –
It is still difficult to reach pump, hope not worse than reaching the fuel shut off solenoid for replacement.
Replacing the fuel pump is about the same as doing the shut off solenoid.  I did both of mine from "above"...one foot on the bell housing and other foot on the frame member along side the engine.  Once you convince your back to bend sufficiently, you have pretty good access to the pump.  My original factory lift pump came off easily - the bolts were not much more than hand tight.  I think the factory engine paint was holding everything together!

Re: Fuel System Science Project

Reply #52 –
Quote from: Alan & Gerri Ortiz –
see if the mechanic ignored the increased size of the new FSS and its effect on the adjacent throttle cable.
If your throttle cable bracket is the same as mine, the mechanic HAD to make some kind of "modification" to get it back on with the new FSS.  What he did is the question...  There are 2 items connected to the bracket (and to your throttle lever): throttle position sensor (for Allison transmission), and the actual throttle cable.  If the bracket was badly bent or otherwise "jury rigged" to make it fit, very possible something is in a bind.

OR, it could be something they did, or did not do, in the process of rebuilding the injection pump.

OR, it might be something in the throttle pedal itself, or the throttle control air valve under the floor, causing the "binding" feel.
 

Re: Fuel System Science Project

Reply #53 –
Quote from: Pierce & Gaylie Stewart –

You also need to see what your fuel pressure at the gauge is at full throttle. Either a sensor with a wire to a remote gauge, a video camera or someone in the compartment while you are going up a hill at full throttle. :D

Pierce

I don't think my DW would like that..... :-X