• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

No Start!

I’m not positive but pretty sure the FASS is a flow through unit so even if it wasn’t working the cp3 should pull fuel from the tank via vacuum as it does in stock oem applications. So I wouldn’t fault the FASS for your no start. I believe the fuel rail pressure sensor needs to see near 5k psi in order for it to open the injectors to allow it to run. Don’t mess with ether. Not really necessary or worth risk on these. If your not seeing ~5k psi at the rail while cranking then pull the return hose off the rail and see if your getting too much fuel return. if no fuel in the return line then cp3 could be toast And not building enough pressure. I had a similar issue with my Lbz turned out to be a ceramic check ball in the cp3 that grenaded, clogged some part of the pump then it finally pushed them through with a lot of cranking and ended up wiping out several injectors. 1 cp3 and 8 injectors later it was as good as new.
 
Fass water filter is a no flow when full set up. Meaning once it absorbs all the water it can- nothing will flow through it.

Imo the biggest improvement on any diesel engine is high end filters like this that save the engine even at inconvenience of stopped engine. But to avoid the problem and diagnose it not just after it happens but leading up to it-
Fuel pressure gauge before the filters and at the inlet of the injection pump.

Then you see lack of pressure and know it is the filter or see pressure both places and know it is not the problem. This also can be tracked and tell you when you actually need filter replacement rather than random guess by mileage. Maybe in one town the fuel is clean and filter is good for 20,000 miles but another town its a rust bucket fuel station and you plug your filter from one fill up.
 
Will L. said:
Fass water filter is a no flow when full set up. Meaning once it absorbs all the water it can- nothing will flow through it.

Imo the biggest improvement on any diesel engine is high end filters like this that save the engine even at inconvenience of stopped engine. But to avoid the problem and diagnose it not just after it happens but leading up to it-
Fuel pressure gauge before the filters and at the inlet of the injection pump.

Then you see lack of pressure and know it is the filter or see pressure both places and know it is not the problem. This also can be tracked and tell you when you actually need filter replacement rather than random guess by mileage. Maybe in one town the fuel is clean and filter is good for 20,000 miles but another town its a rust bucket fuel station and you plug your filter from one fill up.
Click to expand...
I've had the one fill crap diesel before. 70 miles from home.
Drained the T valve and dumped some white power service in it, to make it home.
Pumped a bunch out of the T valve and dumped it in my 500 Gallon tank, then refilled.
It cleared up really fast.

The toggle switch under the hood came in very handy.
 
BigDogYJ said:
I’m not positive but pretty sure the FASS is a flow through unit so even if it wasn’t working the cp3 should pull fuel from the tank via vacuum as it does in stock oem applications. So I wouldn’t fault the FASS for your no start. I believe the fuel rail pressure sensor needs to see near 5k psi in order for it to open the injectors to allow it to run. Don’t mess with ether. Not really necessary or worth risk on these. If your not seeing ~5k psi at the rail while cranking then pull the return hose off the rail and see if your getting too much fuel return. if no fuel in the return line then cp3 could be toast And not building enough pressure. I had a similar issue with my Lbz turned out to be a ceramic check ball in the cp3 that grenaded, clogged some part of the pump then it finally pushed them through with a lot of cranking and ended up wiping out several injectors. 1 cp3 and 8 injectors later it was as good as new.
Click to expand...
I sent the $476.00 lift pump assembly back today.
 
Will L. said:
Fass water filter is a no flow when full set up. Meaning once it absorbs all the water it can- nothing will flow through it.

Imo the biggest improvement on any diesel engine is high end filters like this that save the engine even at inconvenience of stopped engine. But to avoid the problem and diagnose it not just after it happens but leading up to it-
Fuel pressure gauge before the filters and at the inlet of the injection pump.

Then you see lack of pressure and know it is the filter or see pressure both places and know it is not the problem. This also can be tracked and tell you when you actually need filter replacement rather than random guess by mileage. Maybe in one town the fuel is clean and filter is good for 20,000 miles but another town its a rust bucket fuel station and you plug your filter from one fill up.
Click to expand...
Thanks a bunch Will, and Happy New Year!
 
BigDogYJ said:
I’m not positive but pretty sure the FASS is a flow through unit so even if it wasn’t working the cp3 should pull fuel from the tank via vacuum as it does in stock oem applications. So I wouldn’t fault the FASS for your no start. I believe the fuel rail pressure sensor needs to see near 5k psi in order for it to open the injectors to allow it to run. Don’t mess with ether. Not really necessary or worth risk on these. If your not seeing ~5k psi at the rail while cranking then pull the return hose off the rail and see if your getting too much fuel return. if no fuel in the return line then cp3 could be toast And not building enough pressure. I had a similar issue with my Lbz turned out to be a ceramic check ball in the cp3 that grenaded, clogged some part of the pump then it finally pushed them through with a lot of cranking and ended up wiping out several injectors. 1 cp3 and 8 injectors later it was as good as new.
Click to expand...
That sure sounds interesting Big Dog. Happy New Year, and I sure hope that I don't have that kind of luck.
 
Craiglabor92 said:
I sent the $476.00 lift pump assembly back today.
Click to expand...
Just to be clear the FASS system is a phenomenal upgrade when compared to our stock systems.
The ensure that only fuel makes it to the CP3 so no contaminants or air or water make it past its filter setup and keeps a constant 7-10psi (i think) at the CP3 so its not relying on a vacuum to pull fuel from the tank. I run one myself and fully trust it. so hopefully we didn't steer you wrong on that.

As for the return line, you can find that at the end of the fuel rail. No need to get at the CP3 (engine driven High Pressure pump).
But yeah i can imagine the cold makes it worse. I dont enjoy working on my vehicles when it gets below 50F. haha. spoiled in CA.
 
Well, I had a ministroke during the night of December 15th, and the recovery is very slow.
I have a new lift pump and new filters, but at this point in time, I am not sure when I will
get it in. My son has promised to help when he has time. My mobility leaves a lot to be desired.
I will post again when I have some worthwhile news, if I can stay out of the obit.
 
Craiglabor92 said:
Well, I had a ministroke during the night of December 15th, and the recovery is very slow.
I have a new lift pump and new filters, but at this point in time, I am not sure when I will
get it in. My son has promised to help when he has time. My mobility leaves a lot to be desired.
I will post again when I have some worthwhile news, if I can stay out of the obit.
Click to expand...
Hoping for a speedy recovery.

Stay out of the obits. Being wrote up in the papers is way overrated
 
This may be my final post. I have recovered enough to install the new lift pump and new filters with my son's help. We
established good fuel flow right on up thru the fuel filter.
I have cleared the fault P0381 twice, but it keeps coming back, and the Duramax does not make any effort to start. Against the owner's manual instructions, I have briefly started it by using starting either twice, but it dies out as soon as the either is consumed. The fault reads: "Last test failed. This ignition failed." "Since cleared: Failed." The church committee now just wants to get rid of this 24-passenger church bus since we have already bought two Minibuses. I am not able to pursue this further except if the price is extremely low, I might want to buy it myself and continue with this project. I have no idea how much it is worth, but my son knows someone who is offering $2,000. I think that the two new compressors and lift pump assembly are worth at least $1,000.
I sure welcome any suggestions.

Craig
 
You must log in or register to reply here.
Back
Top