Where do I look now?

mrkake · **Posted:** Sun May 15, 2011 1:04 am

I'm stumped on this one. I keep getting a lot of air in my fuel line. I have a lift pump installed near the tank and the LS bleeder valve mod as well as the CAT fuel filter mod. Here's what I know so far;

I got a tank of suspect fuel from a friend's truck tank. The next day on the way to the airport I started losing power just as I was arriving at the parking garage. I limped into a parking space and caught my flight. When I called my friend, he said that he found out that his boss had filled the tank from a farm tank out near a job site. I assumed I had dirty fuel. I had my wife bring out a new filter and leave it in my car so when I got back I changed it in the parking garage and bled it into an empty water bottle. Once the air was out I hopped in and started for home. I made it about 5 miles and it stalled on the freeway. I figured I must have more air so I bled it again and made it off an off ramp. I followed this routine all the way home; stall, bleed, drive and repeat. I had no time to work on it until today. I changed the filter again, bled the air and started it. It idles fine. I let it idle for 45 minutes and then took it around the block. I made it about 1/2 mile before it started losing power. I barely put my foot on the pedal and made it most of the way home before it stalled again. Oh yeah, I forgot to say that i drained the tank before all of this and filled it with fresh fuel. Next I changed the filter again, checked to make sure the o-ring was new and contacting well. I also changed the bleeder valve thinking that this might be where I'm getting the air from. I checked all connections from front to back and kept bleeding until I was sure there was no air (bled off nearly a gallon). I tried driving it again (still idles just fine) and it was going well. Then I punched it and it started to stall again. I am at my wit's end. I really don't know where else to look. Every time I bleed it after it stalls there is a ton of air. Most times it throws a "Fuel Leak (Large)" code. I forget the number. My thought now is that one of the major stalls on the way home originally caused back pressure in the line and created a leak. I honestly don't even know if that could happen. My other thought is the quick connects that are still left up front (got rid of the rear ones when I installed the lift pump). It has been running great with this fuel system configuration for 2 years. Any advise would be appreciated! Sorry about writing a book! I just wanted to get all the details down to help narrow the answers.

BlackLibertyCRD · **Posted:** Sun May 15, 2011 1:12 am

Check the plug on the fuel heater and see of there a leak there. Unplug the wire and pump the plunger and look for leak.

Joe Romas · **Posted:** Sun May 15, 2011 7:28 am

For whatever reason it sounds like the lift pump you put on is not working to me. With a lift pump it should be bleeding it's self and even a melted fuel heater will not allow air in because it will be under pressure and fuel would be leaking out instead. If the fuel was dirty your lift pump could have been damadged :juggle:

So start with the fuse for the "prime pump". Then open the bleeded valve and turn the key on and off a few times and see if the pump runs for the 10 or so seconds spewing fuel out the bleed valve.
If your satisfied the pump is working and still no fuel then you might have a problem with the pickup basket in the tank being clogged up.

Also try eliminating the LS Bleeder

How did you "drain" your tank :?:

The only sure way is to drop the tank from the jeep, remove the pickup assemblie and turn it over.

With all the mods you've done it sounds like you've had ongoing air in the fuel problems :furious:

You didn't mention anything about the fitting for your cat filter, That fitting "sandwiches" the pieces of the fuel head together.

mrkake · **Posted:** Sun May 15, 2011 11:24 am

The puck heater could be a source. I had forgotten the problems with those. The lift pump is fine. It runs for about 17 seconds before shut off and runs a steady stream the whole time (or a bubbly stream these days :evil:

). It is a Wahlbro marine pump designed for small marine diesels. 8 psi and a flow through design so the engine runs fine from the CP3 with it off (tried it right after I installed it to make sure). I did just pump out the old fuel and it was nasty. I guess I better drop the tank and do a thorough cleaning. I just figured since I was getting good flow from the bleeder that I didn't have problems with the pickup tube. Not true? The CAT conversion fitting is just a machined part that has stock threads on one side that screws into the filter head and threads that match the CAT filter on the other side. I thought about converting back to stock (I'm out of CAT filters now anyway). The Lubrication Specialist bleeder mod is just a 1/4" brass valve. I don't have the stock stuff for that anymore. I guess I could put a 1/4" plug in there but then I would have no way to bleed it prior to testing.

I guess these are next; drop the tank and thoroughly clean, check the puck heater, maybe remove the forward quick connects (although these should be under pressure with the lift pump) and figure something for the bleeder. Maybe I'll just get a new fuel manager head to be sure. Anybody know how much those run these days?

Where do I look now?

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