Starts and Dies in the Mornings

Ubie · **Joined:** Mon Oct 10, 2016 11:59 am **Posts:** 4

My girlfriend has a 2005 Liberty CRD and I have spent a lot of time on this forum and working on it in the past few months. The poor Jeep was driven for quite some time before I was dating her with the intake hose in two pieces. I digres....

The Jeep, much like its owner, prefer the warmer weather. The problem is when she starts it on a cold morning, not even that cold <50°F, it will start and then die. I taught her how to bleed the air out of the filter head. She did that yesterday after it died on the shreet and then it died again. After it warms up, there is no problem. I had her let it idle this morning, hoping the fuel heater would solve the issue before driving it. When she went back outside, the engine was not running. Sometimes it has an extended cranking period. Now when you turn the key off it shuts off way faster than normal.

Here is what I have done. P0401 code came up, so I cleaned the egr valve and the check engine light went off on its own. Then the first colder morning we have it dies on her.. Codes P0093 and P0401 are now on. I then unplugged the maf. So I replaced the plastic fuel lines on the tank with rubber and clamped them down well. The connectors on the filter head are dry. Problem still exists. I put some clear plastic tube on the filter head outlet and hose barbeb it to the existing fuel line to the engine. I did not notice any air bubbles. But when I shut the engine off, the fuel level dropped and there was air in the feed line.

Also when I prime the filter head and let it sit for a while, the plunger gets soft and there is air in the filter head again.

I have read a lot on here and would really apprecite some help to what direction I need to go.

Am I still getting air in the system somehow?
Is the check valve in the filter head bad?
Is my crank position sensor bad? (Wish I had a legit scan tool)
Is the problem with the fuel pump in the engine?
Would a lift pump solve my woes?
How can I test what's wrong without slapping parts on it with my fingers crossed?

Thank you,
Ubie

papaindigo · **Posted:** Mon Oct 10, 2016 2:52 pm

Do you have a 1st or 2nd generation fuel filter head; both electric connections black vs one black/one blue respectively? If 1st gen remove driver side (US) electric plug; insert "Q" tip in plug on head; remove and smell "Q" tip; if smells of diesel the heater element is burned out and that's your air source so order new unit from idParts. See my separate posts on installation.

Ubie · **Joined:** Mon Oct 10, 2016 11:59 am **Posts:** 4

It has the second gen style. It was replaced by the dealer a while ago.

Ubie · **Joined:** Mon Oct 10, 2016 11:59 am **Posts:** 4

I did just look at the Jeep again and the FCV is fine. The fuel filter was loose. I changed it a few thousand miles ago and had it tight the . I guess I did not have it lubed well and did not put it on tight enough. We are about to take it on a road trip tomorrow . We will see if it does any better.

I am planning on putting a lift pump inline by the tank when we get bac .

Oh, also after I tightened the filter I primed the air out of the head. After sitting for just a few minutes, the plunger was soft and it had more air in it. The second time I went to prime the head, I heard what I think could be a check valve moving back and forth when I was pushing on the plunger. As soon as I noticed the sound a train started driving by. I never heard that before and I don't know if its normal, just trying to give all the detail I possibility can.

Thanks,
Ubie

papaindigo · **Posted:** Mon Oct 10, 2016 4:38 pm

Couple of thoughts:
1. when changing the fuel filter you need to be sure to remove the small inner gasket with the filter or if it does not come off with the filter remove it from the shaft onto which the filter screws. Failure to do so will result in the filter not seating properly and fuel/air leaks.
2. when you bleed do you a) pump primer until hard; b) open bleeder screw (helps to have a bit of clear vinyl tube run to a catch can) to release fuel/air; c) close bleeder screw gently snug; d) repeat. Failure to do c) will just "slosh" air back and forth without completely bleeding it out.

Ubie · **Joined:** Mon Oct 10, 2016 11:59 am **Posts:** 4

I was sure to remove the old gaskets when I changed the fuel filter.

I am wondering about c). I leave the bleeder screw open until the air/fuel coming out of it has almost stopped, then I close it. I don't wait for it to 100% drain out but 90% of it comes out. I don't want air to get in to the filter from the bleeder screw. I always repeat the bleeding til only a solid stream of fuel comes out. Am I doing this wrong.

Besides, if the jeep is sitting for anytime at all, it will loose firmness on the primer.

papaindigo · **Posted:** Mon Oct 10, 2016 6:23 pm

No shutting the bleeder valve just before flow stops should not be an issue. Although I prefer to bleed with a clear vinyl hose from the bleeder to a catch can, same as bleeding brakes, that way you can see fuel and bubble flow.

Primer does not stay hard. Just checked mine after not bleeding in ages. It's not "soft" but it does take 2-3 pumps to get really hard. I am concerned that when the vehicle sits you say the bleeder gets soft and there is more air. That implies you are a) not bleeding all the air out or b) air is getting in from somewhere. Could be a variety of places:
1. bleeder screw is not seating properly - it's just a standard brake line bleeder screw but if it's not seated properly you should be able to detect fuel leakage with the engine running using a dry paper towel.
2. primer pump shaft seal shot - check under primer with dry paper towel.
3. I assume there is some sort of check valve inside the pump assembly that might have gone bad.
4. when you replaced the plastic fuel lines on the tank with rubber and clamped them down well did you remove both quick disconnect fittings? If not they are a known possible source of air.

An in tank fuel pump will fix an air in the fuel problem or at least make finding a fuel line leak easy.

WWDiesel · **Posted:** Mon Oct 10, 2016 9:12 pm

Contrary to some on this forum; an in-tank fuel supply pump will solve ALL air in fuel problems! Any, and I repeat ANY air in-leakage issues will be self evident the minute you crank up that in-tank pump as any leak point will be leaking diesel fuel since the entire system will be under a positive pressure instead of the CP3 trying to suck the fuel all the way from fuel tank through the fuel filter.... :roll:

An in-tank fuel pump is one of the absolute best mods you can do to a Jeep CRD to stop any possibility of air infusion into the fuel!!!
Once an in-tank fuel pump is installed, air in fuel problems are gone forever!!!! :wink:

mass-hole · **Posted:** Tue Oct 11, 2016 11:25 am

WWDiesel wrote:

Contrary to some on this forum; an in-tank fuel supply pump will solve ALL air in fuel problems! Any, and I repeat ANY air in-leakage issues will be self evident the minute you crank up that in-tank pump as any leak point will be leaking diesel fuel since the entire system will be under a positive pressure instead of the CP3 trying to suck the fuel all the way from fuel tank through the fuel filter.... :roll:

An in-tank fuel pump is one of the absolute best mods you can do to a Jeep CRD to stop any possibility of air infusion into the fuel!!!
Once an in-tank fuel pump is installed, air in fuel problems are gone forever!!!! :wink:

Especially in colder weather when the fuel gets thick. Mine starts so much better in the winter now, just turn the key to run, the pump and glow plugs kick on, then crank it over after a few seconds.

xhizzous · **Posted:** Wed Oct 12, 2016 8:58 am

If you are getting alot of air in the filter head and you have done the other things this board has told you to do check the "Quick Disconnect" where the fuel line runs into the actual cp3 pump on the drivers side of the engine. It might be a Pain to get to if you have not done intake elbow mods and such. I had problems with my 06 with a bunch of air getting into the filter head somehow (after the vehicle was shut down) and I did the rear ones by the tank like you. I switched out the line that runs to the injection pump / replaced the quick disconnect with injector hose clamp and I guess it stopped sucking in air.

Also make sure all the tops on your injectors are dry. You shouldnt get air in the fuel system from here as they should be under pressure, but I have had the little return line from the injector tops leak fuel before.... I believe this return line T's directly back into the fuel supply line.

acuboy · **Joined:** Tue Apr 19, 2011 11:49 am **Posts:** 69

I'm having this exact same issue. Not really that big of a deal as I can bleed the system in about 10 seconds and get on my way. I plan on doing the in-tank pump mod to hopefully solve. But, I have a couple other data points to throw out and maybe that will help someone smarter than me diagnose where it pulling air. So, I have two fuel lines, as I have a veggie oil system installed. Never any issues on the veg fuel line and it's been running great for over 80k miles. So, I don't actually use the diesel line that much, just to reach operating temp and purge before stopping. I have a pressure gauge hooked up so I can monitor both fuel lines. When I'm running diesel it usually registers between -1 and -2 psi, as it sips the fuel to the engine. But now, on a cold morning it will register -4 to -6 and sometimes stall out and need to be bled when starting. The problem is also worse if I park on a grade facing uphill. But here's the part I find really confusing. This whole set of symptoms only occurs when my diesel fuel tank gets to about 1/2 empty. When I top it off the symptoms completely disappear and pressure returns to normal. Changing the fuel filter makes no difference, so doesn't seem related to crud in the tank. Would the weight of the extra fuel create more pressure on the system? It's easy enough to keep it topped off and avoid this whole mess, but if this makes sense to anybody please chime in! Thanks!

flash7210 · **Posted:** Wed Nov 16, 2016 2:20 pm

acuboy wrote:

I'm having this exact same issue. Not really that big of a deal as I can bleed the system in about 10 seconds and get on my way. I plan on doing the in-tank pump mod to hopefully solve. But, I have a couple other data points to throw out and maybe that will help someone smarter than me diagnose where it pulling air. So, I have two fuel lines, as I have a veggie oil system installed. Never any issues on the veg fuel line and it's been running great for over 80k miles. So, I don't actually use the diesel line that much, just to reach operating temp and purge before stopping. I have a pressure gauge hooked up so I can monitor both fuel lines. When I'm running diesel it usually registers between -1 and -2 psi, as it sips the fuel to the engine. But now, on a cold morning it will register -4 to -6 and sometimes stall out and need to be bled when starting. The problem is also worse if I park on a grade facing uphill. But here's the part I find really confusing. This whole set of symptoms only occurs when my diesel fuel tank gets to about 1/2 empty. When I top it off the symptoms completely disappear and pressure returns to normal. Changing the fuel filter makes no difference, so doesn't seem related to crud in the tank. Would the weight of the extra fuel create more pressure on the system? It's easy enough to keep it topped off and avoid this whole mess, but if this makes sense to anybody please chime in! Thanks!

Without a lift pump, the injection pump on the engine has to pull fuel (negative pressure) all the way up and through the fuel filter. On cold mornings the fuel is thicker and harder to pull. When parked uphill, gravity also has a greater effect.
Anything that makes it harder pull fuel through the lines also makes it easier for air to get sucked past a seal and into the lines.

WWDiesel · **Posted:** Wed Nov 16, 2016 3:54 pm

flash7210 wrote:

Without a lift pump, the injection pump on the engine has to pull fuel (negative pressure) all the way up and through the fuel filter. On cold mornings the fuel is thicker and harder to pull. When parked uphill, gravity also has a greater effect.
Anything that makes it harder pull fuel through the lines also makes it easier for air to get sucked past a seal and into the lines.

Good anwser flash!
To add:
Note: the OEM fuel fittings (push on type) are NOT designed to seal under vacuum, they are positive pressure seal type fittings designed for gassers that have a fuel pump inside the fuel tank...therefore they can leak air into the system under vacuum and can leak more when O rings are cold and brittle!!! :wink:

Adding an in-tank fuel pump to the Jeep CRD eliminates ALL air inleakage issues for good!!! :BANANA:

Starts and Dies in the Mornings

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