Oh joy, more air in fuel woes.

silence · **Posted:** Tue Oct 18, 2016 3:00 pm

I've been batting air in fuel problems for 18 months. Changed the fuel filter head assembly to the 2nd generation and was still having problems so I installed an in tank lift pump. After that I was getting sporadic P0093 codes and I noticed I needed more gas pedal then I used to. I changed the fuel filter and everything culminated to Sunday night.

Driving on the highway the check engine light came on and then a couple minutes later the jeep died. The priming plunger was soft as a sponge. And it would not prime, I'm pumping on it for minutes and nothing. Call for a rescue and go home to get tools. I open the strainer valve and turn on the fuel pump, I can hear it running but no fuel comes out. Tow the jeep home.

The next day I drop the tank and inspect the lines. Not pinched, properly connected. With the tank dropped, I turn on the pump and it starts pumping so no restriction in the tank. I blow out the flexible tank lines and the rigid tank lines, no debris. Hook everything back up and bleed the fuel system. It takes a few cycles of the pump but I finally get a firm plunger. I let is sit the night and check the next day, plunger still has resistance and it starts right up. Go for a drive and about 15 minutes into the drive it dies, no check engine light warning this time. And I'm back at square one. I don't think I can do this anymore. These past two days I've had a 1 year old in the back, I just can't have a vehicle stranding me on a highway with a baby.

Any ideas?

flash7210 · **Posted:** Tue Oct 18, 2016 3:39 pm

You have the in tank fuel pump?

Sounds like you've checked the most likely problems.
If the pump is working but fuel isn't flowing, then the problem must be in the fuel tank.
Or you have a intermittent loose wire or bad connection to the fuel pump.

Dgideon · **Posted:** Tue Oct 18, 2016 9:39 pm

Sounds like a power supply problem going to the pump. Did you buy the wiring harness for the in-tank pump from Sasquatch Motor Sports or build your own harness?
Could possibly be the relay or breaker in the load center just forward of the battery. Open that load center and you should find the relay and fuses/breakers are plainly labeled.

silence · **Posted:** Tue Oct 18, 2016 9:55 pm

Yeah this is a weird one. I can hear the pump humming away with the Jeep running and the plunger is firm, but when I drive it all this air is introduced into the system and I can't figure out from where. I'm thinking maybe the filter head. But there is no fuel coming out of the line connections or the filter head when the in tank pump is running.

GordnadoCRD · **Posted:** Wed Oct 19, 2016 3:08 am

Is your tank completely clean? I once had one with just a bit of crud that when sloshed against the in-tank screen would plug it, completely stopping flow, but when pulled out it was clean and working fine.

rankom · **Posted:** Thu Oct 20, 2016 7:09 pm

you need to check fuel pressure ( mechanical gauge) at FFhead it is possible that pump module flex tube cracked and bypassing fuel back into fuel tank , loosing pressure , ? if that is the case you need to drop duel tank again and pull pump module for inspections , also is your pump AIRTEX 8psi or OEM DODGE 14psi ?

silence · **Posted:** Fri Oct 21, 2016 10:39 am

It's the Carter pump. Is there an easy way of looking into the tank without pulling the pump back out? Compressing the packing and installing that ring was such a pain in the booty.

WWDiesel · **Posted:** Fri Oct 21, 2016 10:59 am

Sounds like your pump may have gone bad; it happens, changed bunches of them on gasers....

B4NGER · **Posted:** Tue Nov 22, 2016 4:19 pm

Just a Note, I have the in tank Lift pump also that I installed, my wife went to take the jeep to work and it puttered and died right out of the driveway and threw a check engine light. She Pulled up a P0093 code for running out of fuel. She didn't get far so she was able to get it into the driveway and just leave it. Found when I got home that the plunger on the filter head was suctioned down against the base, turned key on and listened for pump, no noise. Found that the Fuel priming fuse was blown. So what happened was that it blew the fuse and the suction CP3 pump on the engine was unable to suck enough fuel through the now non working Lift pump. I replaced the fuse and the pump seems to be working fine now and jeep has no issues on 2 days of test drives. Wiring looks to be sound but I do have some corrosion where the fuel priming fuse is located in the fuse block.Most likely for never being used up until 4 months ago! Perhaps you have some also? causing an intermittent connection? or some wiring/ground that is loose/Chafed. A fuel pressure gauge in the fuel supply line would tell you what really going on. Also hopping out when the jeep stops and checking the plunger position and the fuel pump operation? hope you get it figured!

papaindigo · **Posted:** Tue Nov 22, 2016 5:01 pm

Corrosion is easy enough to clean off but I am wondering what type of in tank lift pump you have. Most recommendations on lift pumps stress a flow thru pump such that if it fails it fails "open" so the CP3 can still pull fuel.

Oh joy, more air in fuel woes.

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