Some crazy fuel problems

[firemedic211]

OK so here goes i bought my CUCV from a private party in middle ga. The mech fuel pump was not working correctly so i replaced it with an airtex 8153 universal diesel pump. I removed the mechanical completely, put a bypass hose where the mechanical should have been and put the block plate on (thanks btw I've been creeping around the forums to get to this point) I bled all my lines all the way to the injectors and cranked the truck, At this point i felt about 30-45 secs of elation! then it revved up a little and died No problem repeated all the steps and kept my foot halfway down on the accelerator this time, same result. I put a HUGE 10micron spin on filter before the airtex pump that was clear so i could see whats going on, I bled the system it cranked and died AGAIN. So I am just checking to be sure before I do it, I probably need to drop the tank and see if the sock is clogged? and while i'm at it replace any rubber lines? I'm almost to the point of taking it to a mechanic and just telling them to fix it.
Thanks in advance
ash
Ohh btw my truck has shelves right behind the cab and a bunch of power outlets in a box that has a power switch on the driver side i was told this was a medevac truck? i have no clue if thats right but its going to be used on a hunting preserve and i don't need it there

 

[firemedic211]

OHH I FORGOT! when I bleed the fuel system to the filter on the firewall i get clean diesel no air bubbles in it

 

[AceHigh]

The shelves sound like a radio set up.

Are any rubber lines on the suction side? Can they collapse?

I went through the same stuff, finally changed the fuel tank, all lines, pump and filter. Seems there was a lot of algae in the lines and the new pump woke it up and sent it downstream. Good luck!

 

[NCBloodhound]

Before dropping the tank check the fuel pressure coming out of the filter. Check the TMs for the expected PSI, but I believe it is between 5.5 and 6.5. Also check the return valve on top of the IP and see if is is clogged.

 

[southdave]

Rubber lines though the frame check those also the fuel filter housing are problematic as well as some of filter fit up from different manufactures ... don't for get to check the check valve on the IP..

 

[kapnklug]

Before you go dropping the gastank, first try blowing out the sock with compressed air (into the fuel line, before the pump). If it improves for a while but then plugs again, it's probably junk in the tank plugging up the sock.
You can also pressurize the whole fuel system from the IP back to look for leaks that might be sucking air.

 

[firemedic211]

blowing out the tank worked! you guys rock thanks a ton!

 

[southdave]

Use a small 50micron in line filter before the pump.. your pump pushe more fuel than suck

 

[cucv1833]

Before you go dropping the gastank, first try blowing out the sock with compressed air (into the fuel line, before the pump). If it improves for a while but then plugs again, it's probably junk in the tank plugging up the sock.
You can also pressurize the whole fuel system from the IP back to look for leaks that might be sucking air.

That what i do every time I change my fuel filter. I take the hose off the fuel return check valve and check the valve for junk.

Then blow 2-3psi of air in the tank through the return hose and pressure up the tank to check for leaks and prime and bleed the air out the fuel filter at the same time.

 

[kapnklug]

Glad blowing out the pickup sock worked. Of course all that junk that was plugging the sock is now still in the bottom of the tank. So here's what you do: in the pass. rear wheelwell near the top of the frame, you'll see an extra hardline coming from the tank, that is capped off. This is a purge line that goes to the very bottom of the tank but has no sock on it. Remove the cap and connect a long clear hose to this line, then suck on it to start a siphon action (or you can use an electric pump, but be sure to put a filter in front of it). You should see all the crap from the bottom of the tank start flowing thru the clear hose. When you see clear diesel coming thru the hose, stop sucking and replace the cap.

 

[firemedic211]

Sweet

Ok so an update drove the truck around the block a few times no problems really so I decided for a longer run truck went about a half mile and died it cranked right back up and I drove it home it has no problems starting but I am getting alot of white smoke while driving if I rev it up in the driveway I don't get the smoke but in gear going down the road I do I've looked and I can't find any similar threads