Behaves intermittently like it's out of fuel

lapindata · **Joined:** Mon Aug 28, 2017 4:10 pm **Posts:** 7

I have an '05 Diesel Jeep Liberty with what seems like a fuel system issue.

Two times a few days before this inability to start I remember it taking a half dozen cranks to start — that became no start one evening, which had me thinking then I was out of fuel with car parked on an incline nose down. I rolled to a flat spot, put 5 gallons in, and it wouldn't start; came back next morning to have it towed and it started right up.

A few days later again no start and had it towed to my mechanic who is competent, but not a diesel specialist. They found the high pressure fuel pump had lost prime and once primed had no issues starting. I took it back, drove for a few days and after sitting in the drive over the weekend, no start again Monday morning. Back at the shop he saw no codes and had it towed to the local Jeep dealer to scan.

Dealer 1 in NY found no codes either and tapped out saying they never sold the diesel in NY state. I had it towed to a Dealer 2 in PA where these were originally sold, and {beyond finding the battery fried which they replaced} had no issue starting it except for once..... talk about intermittent. That one time again threw no codes.

Dealer 2 in PA found the harness attached to the Fuel Filter/ Water Separator was jury-rigged and got the right part and replaced. They continued to find no issue starting and sent me on my way. I drove the jeep home that day 40 minutes, pulled into a store to buy milk, and no start! ....I hand-primed the high pressure pump and it started. That was Saturday afternoon, and it has started every time I've tried since.

Dealer 2 says if there was an air leak, I'd be able to smell diesel, so not sure then what would cause the pump to lose prime.

Prior to these recent events there has never been any hesitation starting. In the dead of winter at 4 degrees, it cranked twice and started fine. I posted an earlier version of this question on another forum and it was suggested I post here. They recommended as follows:

"The high pressure pump, on the engine, usually isn't the problem.

"Air in fuel" is common in the Liberty diesel, many reasons why.

Original equipment fuel filter head, plastic, develops leaks letting air into the fuel system. Replace with an identical looking fuel filter head, metal. If the electrical connecter on the drivers side of the fuel filter head is blue you have the metal head. Scratch it with a blade if you're not sure.

There isn't a lift pump in the fuel tank from the factory so the on-engine fuel pump so it has to suck the fuel all the way from the tank past fuel line connectors that are designed to seal under pressure, they suck air. Solution is to add an in-tank lift pump or in-line electric fuel pump.

Sometimes the metal crimping attaching metal ends to rubber fuel lines can let air in.

Try using the hand pump and bleed screw on your fuel head to bleed air out of the system and see if it runs.

Also check the fuse for the glow-plugs to see if they're in the game. Seems like that would throw a code though.

Dealers don't seem to have any expertise with our little diesel so you might want to explore other possibilities.

The wiring kit Dealer 2 installed has a bright blue connector, which if I read the post above correctly, is what is suggested. Thoughts on ways forward, on on how dire this new issue is are appreciated. It's my only truck so really can't afford to be turning this into a hobby project through a dark winter coming....

flash7210 · **Posted:** Mon Aug 28, 2017 6:10 pm

Good. Dealer #2 installed the newer updated fuel filter assembly.

If you continue to have air-in-fuel problems:
Step 2- fix the fuel line connections back at the tank
Step 3- install a lift pump

Question:
How many mile does yours have and has the timing belt been replaced?

lapindata · **Joined:** Mon Aug 28, 2017 4:10 pm **Posts:** 7

flash7210 wrote:

Good. Dealer #2 installed the newer updated fuel filter assembly.

If you continue to have air-in-fuel problems:
Step 2- fix the fuel line connections back at the tank
Step 3- install a lift pump

Question:
How many mile does yours have and has the timing belt been replaced?

I'd be psyched had it already not started again.. especially frustrating since Dealer 2 only got to observe the issue one time [only to really ascertain there were indeed no codes]

I purchased with 93K miles, and now have 134K miles. I had the timing belt and complete rocker arm/ lifter set replaced at 120K miles as it took that long to find someone who'd do it. That increased my gas mileage 2 miles/ gallon. On a long steady road trip I've gotten it up to 38mpg based on the car readout.

I had no idea how timid shops are about working on these — and found it amazing Dealer 1 asked me to go somewhere else: they offered no diagnosis fee for their time, but I didn't learn the battery was shot until it was at the next shop so maybe that was why too.

As for your recommended steps 2 and 3, by fix, do you mean replace? What is that connection is like.... welded/ union?

Is there no in-tank pump on these/ so a lift pump would be an aftermarket unit?

GordnadoCRD · **Posted:** Mon Aug 28, 2017 9:08 pm

*accidental duplicate*

GordnadoCRD · **Posted:** Mon Aug 28, 2017 9:40 pm

lapindata wrote:

flash7210 wrote:

Good. Dealer #2 installed the newer updated fuel filter assembly.

If you continue to have air-in-fuel problems:
Step 2- fix the fuel line connections back at the tank
Step 3- install a lift pump

Question:
How many mile does yours have and has the timing belt been replaced?

I'd be psyched had it already not started again.. especially frustrating since Dealer 2 only got to observe the issue one time [only to really ascertain there were indeed no codes]

I purchased with 93K miles, and now have 134K miles. I had the timing belt and complete rocker arm/ lifter set replaced at 120K miles as it took that long to find someone who'd do it. That increased my gas mileage 2 miles/ gallon. On a long steady road trip I've gotten it up to 38mpg based on the car readout. EVIC readout is notoriously inaccurate as far as a specific number, HOWEVER they are generally consistent, so are good to note whether a change has resulted in mileage up, down, or no change.

I had no idea how timid shops are about working on these — and found it amazing Dealer 1 asked me to go somewhere else: they offered no diagnosis fee for their time, but I didn't learn the battery was shot until it was at the next shop so maybe that was why too. It is fortunate you found a shop that is honest enough to admit they are out of their realm of specialty. It's far more common to find ones that screw things up, then pass it back and charge you for it.

As for your recommended steps 2 and 3, by fix, do you mean replace? What is that connection is like.... welded/ union? The connection is a hard plastic quick release that slides over hard plastic fitting at the exterior unit connection (top of the fuel tank), forward over the rear axle, and joins the formed steel factory line above and forward of the rear axle where the steel line then runs to the left interior of the left frame rail, and forward to the fuel filter area. Each end if this hard plastic line has one of these quick release fittings that are highly prone to letting air enter without having any evidence of fuel leak, either visible or by smell.

Is there no in-tank pump on these, so a lift pump would be an aftermarket unit?

Not necessarily an aftermarket unit. What the diesel Liberty comes with, is an identical unit body as the diesel Cummins unit but with ONLY a fuel level sending unit installed. No pump. The best fix, in my opinion, is an OEM factory-type in-tank pump that fits any dodge pickup with a Cummins diesel. You can get aftermarket branded versions of this unit as well. The Liberty has a power circuit with both fuse and relay plumbed in the factory loom as far as where the loom connector to the section that exits the interior under the left rear seat carpeting. They are not cheap, but they pressurize all pre-cp3 fuel and make all air-in-fuel issues a thing of the past. Air CANNOT enter against positive psig.
Others have had a measure of improvement by installing an aftermarket pump between the fuel filter and the steel line from the frame rail. This doesn't fix the air incursion problem, it simply gives the OFV in the CP3 less negative pressure so it can deal with it better.

lapindata · **Joined:** Mon Aug 28, 2017 4:10 pm **Posts:** 7

GordnadoCRD wrote:

Is there no in-tank pump on these, so a lift pump would be an aftermarket unit?

Not necessarily an aftermarket unit. What the diesel Liberty comes with, is an identical unit body as the diesel Cummins unit but with ONLY a fuel level sending unit installed. No pump. The best fix, in my opinion, is an OEM factory-type in-tank pump that fits any dodge pickup with a Cummins diesel. You can get aftermarket branded versions of this unit as well. The Liberty has a power circuit with both fuse and relay plumbed in the factory loom as far as where the loom connector to the section that exits the interior under the left rear seat carpeting. They are not cheap, but they pressurize all pre-cp3 fuel and make all air-in-fuel issues a thing of the past. Air CANNOT enter against positive psig.
Others have had a measure of improvement by installing an aftermarket pump between the fuel filter and the steel line from the frame rail. This doesn't fix the air incursion problem, it simply gives the OFV in the CP3 less negative pressure so it can deal with it better.[/quote]

Thank you for that input — you make it clear the issue would likely be solved with a fuel lift pump in place.

Wondering why though after 30 months/ 30k miles driving this trouble never reared its head.... I suppose it could be simple wear and age finally compromising some part of the system.

I see this excellent manual on procedure for said replacement: http://www.auerbach.ca/kj/lift_pump/ and seems a lift and experience reduces this 20hr job to 2.5hrs. I have an experienced diesel mechanic in mind to ask now that I have this approach... he has a lift in his home garage to do sidework, but wanted to avoid tying up his shop in a lengthy diagnosis, especially since I've said the issue is so intermittent.

Would it be ok to PM you if in discussing he raises questions I can't answer?

Thanks again

mass-hole · **Posted:** Tue Aug 29, 2017 1:04 pm

lapindata wrote:

Thank you for that input — you make it clear the issue would likely be solved with a fuel lift pump in place.

Wondering why though after 30 months/ 30k miles driving this trouble never reared its head.... I suppose it could be simple wear and age finally compromising some part of the system.

I see this excellent manual on procedure for said replacement: http://www.auerbach.ca/kj/lift_pump/ and seems a lift and experience reduces this 20hr job to 2.5hrs. I have an experienced diesel mechanic in mind to ask now that I have this approach... he has a lift in his home garage to do sidework, but wanted to avoid tying up his shop in a lengthy diagnosis, especially since I've said the issue is so intermittent.

Would it be ok to PM you if in discussing he raises questions I can't answer?

Thanks again

The lift pump is not too bad to install. Its 4 bolts that hold the fuel tank straps on and a few other misc things like the filler tube and disconnecting the fuel lines on top of the tank. The wiring honestly took the longest and you can now buy the harness completely assembled from Sasquatch parts which takes some of the PITA out of that. I would say that if you brought it in with the harness ready to go it would only be a couple of hours on the lift.

One thing to mention is that getting the new pump in can be kind of a pain because its a twist-lock type setup. You have to compress the oring to get the tabs on the twist lock to drop into place before you can turn it. I put a little grease on the oring and then placed my knee on the top of pump, pressed down, then used a hammer and piece of wood to spin the pump into the lock position. It only took about 5 minutes.

lapindata · **Joined:** Mon Aug 28, 2017 4:10 pm **Posts:** 7

Sounds good. The harness, now discontinued from Mopar, was $36 and now $230..... sheeesh

Curious for any input on differences in the listed versions for fuel pump?:
Cummins 5143160AA
Airtex E7181M
Spectra Premium SP7181 — If the Spectra works fine that'd be great.

mass-hole · **Posted:** Tue Aug 29, 2017 2:17 pm

lapindata wrote:

Sounds good. The harness, now discontinued from Mopar, was $36 and now $230..... sheeesh

Curious for any input on differences in the listed versions for fuel pump?:
Cummins 5143160AA
Airtex E7181M
Spectra Premium SP7181 — If the Spectra works fine that'd be great.

The OEM gas harness required rewiring to work with the CRD. The pinouts on the plug under the rear seat was not the same between the two engines so it was not 100% plug and play and required removing some pins and reinstalling them. Sasquatch's is pre-wired correctly for the CRD which would be the main benefit there. My guess is that purchasing the proper pins and harnesses to make his own is not cheap.

I have the Airtex which dropped right in. I assume the Spectra is the same, just check the operating pressure on them. I cant remember but I thought it was like 15 psi.

lapindata · **Joined:** Mon Aug 28, 2017 4:10 pm **Posts:** 7

mass-hole wrote:

lapindata wrote:

Sounds good. The harness, now discontinued from Mopar, was $36 and now $230..... sheeesh

Curious for any input on differences in the listed versions for fuel pump?:
Cummins 5143160AA
Airtex E7181M
Spectra Premium SP7181 — If the Spectra works fine that'd be great.

The OEM gas harness required rewiring to work with the CRD. The pinouts on the plug under the rear seat was not the same between the two engines so it was not 100% plug and play and required removing some pins and reinstalling them. Sasquatch's is pre-wired correctly for the CRD which would be the main benefit there. My guess is that purchasing the proper pins and harnesses to make his own is not cheap.

I have the Airtex which dropped right in. I assume the Spectra is the same, just check the operating pressure on them. I cant remember but I thought it was like 15 psi.

That's appreciated, thank you!

GordnadoCRD · **Posted:** Tue Aug 29, 2017 3:33 pm

I don't know your situation regarding this project.

There are very thorough threads even with illustrations, about the Lift Pump Mod. Here are some tips that may or may not be helpful.

I used the Carter unit listed below in my sig. It's original application is 2006 Ram 1 ton w/Cummins

If time is more important than money, go this route. It's Brand new, with a warranty, and they make a plug-and-play harness that takes all the monkey business out of what gets wired to where, and how to get the wires in to the wires inside without making water leaks.
Seriously, if you've got the money, it's worth it.

If you don't, you can check around at bone yards that have any dodge diesel trucks that had Cummins engines. The in-tank pump / sending units are all usable. You might get a better price for a used one. If you have a vast amount of patience and skill, you can run your own wires and fit your own connector terminals.

If you have the steel tank skid, and factory hitch that bolt to the frame rails on either side, those are really bloody awkward, and two people make it much faster and less risk of injury. That goes for both removing and reinstalling.

Empty the tank before you start. Completely. Pretty much any transfer pump that can pull a couple feet of head will work if they are OK with diesel. Disconnect the plastic lines from the steel lines in front of the tank, but leave them attached to the old unit on top of the tank. It's so much easier removing and installing these when the tank is removed.

Pulling the filler tube and all the vent lines is a temporary annoyance, but worth it to be able to work on the tank unobstructed. This also goes much faster if you have one person to work the locking ring and the other to hold the tank still. Lube. Lots of it, makes removal and installation of the locking ring MUCH easier. Silicone spray... Lithium grease... even Vaseline.

The Vehicle Lift is just as useful in the pulling the rear left seat part. So much easier to work on things at chest level than inverted and bent backwards at ground level. It doesn't need to actually come out, just flip it over on it's back to get it out of the way.

lapindata · **Joined:** Mon Aug 28, 2017 4:10 pm **Posts:** 7

great input

My situation is I was blindsided by this issue as I never had any hint of the vehicle not starting prior to a month ago. I got off on the wrong foot letting the the Chrysler dealer advise, as they want me to see this as a nearly insolvable mystery. That [inconclusive] diagnosis, a new battery after mine being drained to death... and I'm in it for about $700. At least that work included installing the right fuel/ water separator harness which was apparently very jury-rigged.

So this retrofit improvement is another $400 in parts, and shooting for the 2.5 hrs labor.... it's adding up and well outside any kind of resale value.

But you guys are helping me to see the light at the end... when working, the Jeep suits me great — I own it outright, pulls my work trailer like it's not even there, and gets great mileage on long commutes on jobs.

Behaves intermittently like it's out of fuel

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