I have been parking on gravel since I swaped out my lift pump so I haven't noticed what I found today. I looked at my fuel line and noticed that diesel had been running down it. The puddle on the ground was only about 2" in diameter. It appears that the quick connect fitting supplied in the kit does need a hose clamp. The male fitting that screws into the fuel filter housing seems to be the culpret. As soon as I get a chance to get to the hardware store before it closes I will put the hose clamp on and see what happens. Either way this leak could not be injecting air into the system. I'm not sure what my fuel psi is I just got my tranny and fuel pump so I need to save up for the $300 fuel gauge.

 

If quick connect fitting you mean a hose barb don't put a hose clamp on it. Eventually the clamp will cut the hose from the inside out. I would just cut it off, apply some engine oil to the barb and hose and push it on. I'm not familiar with the walbro kit but push locks are good for 250 psi with no clamp required. Without a fuel pressure gauge how can you adjust the by-pass regulator?

 

There is no bypass regulator. There is a return line for the excess fuel with a check valve in it. I assumed that if I was pumping more fuel than needed I should be blowing smoke.......shouldn't I. No matter what setting on the Juice I have it on, I can blow smoke for the life of me. This I thought meant that I was optimizing the fuel being sent to the motor and was not wasting any of it...hence the smoke. If I am wrong please correct me.

 

Yes Theoreticly if you increase the inlet pressure,you will increase the output pressure.IF everything else stays the same.Your ECM will call for a given rail pressure at a given load,& it will still be useing the MPRV to achieve that pressure.Net result same rail pressure.Just a different MPRV setting.All controlled by the ECM.

 

Correct me if I'm wrong here but you really need to regulate the cp3 inlet pressure on a non modded cp3. I believe that anything over 15psi is totally wrong on a stock cp3. When the dude who brought all this to the boil, you know (HE was banned...hint)? He designed the wally pump setup with a regulated bypass at 15 psi. If a man goes through all the trouble on setting up a alternate fuel supply pump don't ya think a fuel pressure gauge is called for? For the record if you increase the fuel supply inlet pressure no you do not increase the output pressure on a STOCK cp3. The cp3 is a three stage FCA controlled pump. Any increase in pressure results in heated returned fuel. Correct me if I'm wrong.

 

"trik" yes I did read the info on the CP3 from the internet. But not satisified with that, I sent an Email to Bosch. With no response from them towards my email. I called their European 1800 number and talked to their tech line. Lots of valuable info about how the pump works and the increase of pressure.
But values were vague.
As for inlet pressures 0 psi will suffice as long as the volume is with in spec of in or around 40-60gph. But I was informed that running 10-14psi is normal operating of the CP3 in our application. Further to that any increase in the head pressure would result in a higher rail pressure. That was stright form their Tech line.

As for how and why it effects our engines well it is pretty long and drawn out. Needless to say the truck runs at preset settings, those settings are not set hard in the way you would think. Ie 5000psi @ idle may actually be 6000psi. To many variances to account for.

With the higher head pressure the CP3 is able to get to it's rail pressure quicker. Hence better response and ability through out all operating parameters.

On a side note to this the CP3 family of pumps is used in many different applications from small cars to heavy trucks. They all share the same common components but are all spec'd to run at different sustained flows and pressures.

 

If it's leaking fuel air can get in. I wouldn't suspect the AN pushlock. I have them on my shop air lines and they run at ~120 psi with no hose clamps. My whole FASS system along with my big line kit is utilizing the AN fittings with no clamps anywhere. If I were you I would carefully look at the block on the inlet to the filter housing. There is an o-ring on that fitting and it is prone to pinching is it isn't exact. If that is indeed leaking then I would bet that is the problem.

As N.Johnson said, do not put a hose clamp on the pushlock. It will eventually cut through the hose. Next, I would seriously look to a pressure gauge for reassurance.

Hope you get it figured out. Keep us in the loop.

 

Juice,

This post was taken from the thread "Cool it down". Your temps seem normal for a modified truck (actually pretty good). If you were only seeing 1150° with the Juice on 5 I would guess your rail pressures were low. Your temps were lower prior to the pump install because the CP-3 wasn't being supplied properly.

I never heard back from you but I'm still assuming that this is one of our kits. If you have a leak at the bottom of the filter adapter remove the PushLok fitting and add a small amount of thread sealer to the fitting before re-installation.

Richard

 

I had a similar problem after installing my kit this weekend. If your seeing fuel running down the feed line from the adaptor, check the plug on the top side. Mine was leaking fuel slightly and letting air into the system. I pulled the plug out and resealed it and it runs great now.

 

IMHO it is always good to use a little diesel resistant pipe dope. it also makes it easier to torque down the fittings...when they are hard to reach...and makes them possible to undo if it is ever needed. Remember...do not get the dope where it can be flushed into the line.

 

I had planned on doing the same repairs on Friday (do to a heavy work load). I am 99.98% sure that by pulling out the inlet barb fitting on the filter housing and resealing it the leak will stop and who knows, I may just get .5mpg increase without fuel dripping down the hose all the time. Thanks for all the input I definately have a better understanding of how exactly our fuel pumps work.