Stalling all the time

splatinc@hotmail.com · **Joined:** Wed Apr 04, 2012 12:32 pm **Posts:** 10

Howdy everyone, this is my first post here but I am already thankful for the knowledge recieved.

So my 06 CRD started stalling when under heavy acceleration onto the highway, now it has started to stall in regular 35 mph traffic. I had the guys at the lube place spray round the injectors and check under the body and there are no obvious leaks. I can/have to pump and purge the fuel filter every time I start the jeep.

I have ordered a new fuel filter and will install it later this week. I am also thinking about getting an external lift pump as well.

Would a bad fuel filter cause air to get in? There is no obvious leak at the filter head (yes I did check the heater plug).

Any thoughts for the source of my woe? Does anyone have a suggestion for an easy install lift pump?

Since I found this site this weekend I have already cleaned my MAP sensor and unplugged the MAF Sensor. The green diesel tune also looks very inviting.

Thanks everyone!

msilbernagel · **Posted:** Mon Apr 09, 2012 3:40 pm

Hello and welcome!

You can probably pick up the whole history / big picture of the air-in-fuel issues with a search or two, but the short version is this:

Original (gas) design had an in-tank pump and pushed fuel to the engine.

Diesel version uses the Bosch CP3 engine-mounted pump to 'pull', and therefore create a vacuum, fuel from the tank and through the filtering head and into the engine.

Air typically enters the system at the snap fittings (disconnects) near the fuel tank. Theory here is that the fittings were designed to be pressurized, and that they begin allowing air to enter as the vacuum increases. There also seem to be some variability between one fitting and the next, so some folks experience more problems than others. The fuel filter head may introduce more air but most likely just serves as a air-collection point since it is the high-point in the flow of fuel from tank to engine.

As fuel filters become increasingly restricted with use, the vacuum increases (the Bosch is an incredibly strong pump) and the air increases.

Best solutions seem to involve a fuel filter close to or inside of the tank, and quite a few folks switch filter heads as the newer designs have fewer problems.

Mark

msilbernagel · **Posted:** Mon Apr 09, 2012 3:47 pm

Oh, and when replacing the fuel filter make sure the old o-ring at the top of the filter comes off. It often sticks to the head, which is below your eye-level and therefore out of sight. If you miss it and end up with two (old, stuck) and the new one on the filter you get non-stop headaches until you figure it out.

I believe racertracer just mentioned this issue elsewhere.

FYI -

Mark

papaindigo · **Posted:** Mon Apr 09, 2012 3:52 pm

See Sir Sam's NOOB guide for the fuel head bleeding video and a picture of the 2n gen fuel filter head. If you have a 1st gen head it's likely getting air in via the heater element even if you cannot see fuel there (been there done that)

splatinc@hotmail.com · **Joined:** Wed Apr 04, 2012 12:32 pm **Posts:** 10

I have already searched this group extensively thats why I have already ordered a fuel filter and am thinking about a lift pump.
Thanks for the advice about the o ring. I will be removing the whole assembly so that shouldn't be an issue.
I use that sir sam video already to purge.
Is there a way to seal up the heater plug thats not permanent? The plug shows no signs of being burnt.
I have the original filter head and will replace when I have funds available.

Once again, what is an easy install external lift pump?

papaindigo · **Posted:** Mon Apr 09, 2012 4:45 pm

1. "not" permanent sealing of the heater plug? None that I know of. FYI mine showed no external signs of being burnt but it did when I had the filter off and the head upside down. FYI the new 2n gen filter head comes with a new fuel filter and WIF installed (save your old WIF for possible future needs).
2. in line near tank install see http://liberty.eurekaboy.com/kennedy.htm
3. in line in engine bay install see viewtopic.php?f=5&t=24527&hilit=automatic

For what it's worth the Kennedy lift pump (http://www.kennedydiesel.com/categoryre ... egory2=126) is very good but very pricey. An alternative is a Facet 40109 (http://www.yachtsupplydepot.com/mechani ... t_697.html) or I understand there are some low PSI in line pumps for the GMC 6.5 diesel. Again for what it's worth I had the air in fuel problem and purchased the 2n gen filter head and Facet pump; the filter head has been installed for 10K miles and the Facet is still in the box and I have no air in the fuel problems. From that you can guess where I'd recommend spending your $s in the near term.

splatinc@hotmail.com · **Joined:** Wed Apr 04, 2012 12:32 pm **Posts:** 10

Well, I have Macguyvered a plug of the heating element with modeling clay and electrical tape and will try it out in the neighborhood.
I appreciate the advice about the filter head and will see if I can change my order with the parts warehouse.

BobFarley · **Posted:** Tue Apr 10, 2012 1:18 pm

First thing you should do is determine where the air is leaking...per the factory service manual connect a piece of 3/8" ID clear tubing between the fuel supply line coming from the tank and the inlet on the filter head. I used a 5 foot piece so I could loop it out from under the hood near the hinge and back under and check for bubbles while driving. Once you've hooked up the vinyl tubing prime air out of the line, fire it up and look for bubbles. I had a major leak at idle which produced several large bubbles. This will tell you if your leaking air between the tank and the filter head. Likely culprit between the two is the pesky quick connect fittings which fasten the plastic lines to metal lines near the front of the tank. If no air bubbles in tubing then switch to outlet side of filter housing and hose to injector pump. If you see air bubbles here but not in first circumstance then your filter head is bad and leaking air.

I think you can expect to see small bubbles while driving but shouldn't see any while idling...unfortunately I think as others have said the system wasn't designed to be under pressure and therefore is prone to leaking unless under pressure from the tank i.e. lift pump.

splatinc@hotmail.com · **Joined:** Wed Apr 04, 2012 12:32 pm **Posts:** 10

50 Points to BobFarley for having the best advice so far!!!
:pepper:

Really though, that is the kind of advice I need to solve the problem not just mask it.

splatinc@hotmail.com · **Joined:** Wed Apr 04, 2012 12:32 pm **Posts:** 10

So, I got the tubing and went to work. I believe I have isolated the issue to the filter head. I haven't had a chance to see many bubbles cause the flow of fuel is very restricted. It causes the clear tube to flatten while idling. If i rev at all I choke off the engine.
I did successfully change my order to a filter head instead of just a filter.
This picture shows the current attachment of the hoses, (just in case I had anything wrong).
Thanks to everyone and their assistance.

http://gallery.me.com/splatinc#101634/P4100002&bgcolor=black

BobFarley · **Posted:** Tue Apr 10, 2012 6:03 pm

Sounds to me like your filter is clogged...excessive suction created by lack of fuel being pulled through the filter causing the hose to collapse. If the filter was unrestricted I think the suction would be the same on the inlet and outlet sides of the filter head. Sounds to me like you have high vacuum on one side and low vacuum on the other.

splatinc@hotmail.com · **Joined:** Wed Apr 04, 2012 12:32 pm **Posts:** 10

So the theory is that the high vacuum is causing air to leak in through minuscule imperfections in the filter head?

I should have the replacement parts by Friday. I will post the results then.

Herk · **Posted:** Tue Apr 17, 2012 2:38 am

I have the same issues. I put my finding on the thread line lift pump suggestion. AK

liberty2.8 · **Posted:** Thu Apr 19, 2012 8:40 am

Quote:

Since I found this site this weekend I have already cleaned my MAP sensor and unplugged the MAF Sensor. The green diesel tune also looks very inviting.

Not sure if the stalling you mentioned was more of a limp mode that went away or not. After I cleaned my MAP for the 1st time I began experiencing a lack of power at acceleration and at the most inconvenient times while in traffic; couldn't get out of my own way and it was getting really aggrevating. Sometimes I would have to pull over and stop/start engine. After reading several threads here about self induced problems from cleaning the MAP with certain solvents, I decided to try a new MAP. Put new one in and problem went away for good. Also by unplugging the MAF, the new MAP stayed much cleaner.

papaindigo · **Posted:** Thu Apr 19, 2012 2:35 pm

The CRD fuel pump is the CP3 mounted on the engine block and driven off the timing belt hence that pump functions just like a old gasser fuel pump mounted on the block and "pulls" fuel from the fuel tank hence the fuel system from the fuel tank to the CP3 is under something resembling a vacuum (e.g. stuff is being sucked thru it). The KJ gasser fuel pump is located in the fuel tank and "pushes" fuel to the engine hence from the tank to the engine that line is pressurized. The CRD and gassers share the same fuel line design with quick disconnect fittings that are designed primarily to keep fuel from leaking out not air from leaking in. Add to that the fact that diesel is "thicker" than gas and hence harder to "pull" from the fuel tank.

Put all of the above together and any tiny problem with the quick disconnect fittings or in the filter head (on the 1s gen head commonly problems with the fuel heater seal) and air gets into the system. Given that the top of the fuel head is the high point in the system the air collects there until it completely cuts or intermittantly cuts fuel supply to the engine.

Lots of solutions. What worked for me was the 2n gen fuel head. Other options - in line lift pump helps (I have one on the shelf but never installed); in tank pump; getting rid of the quick disconnects.

NOTE for all to keep in mind. Since the diesel system operates by "pulling" fuel it follows that air is pulled into the lines and diesel is rarely if ever pushed out between the tank and the CP3. To put it another way - if air is in your fuel system between the tank and the CP3 it's being pulled into the system and looking for where by trying to find a diesel leak is often a total waste of time. Example: I positively had air coming into my fuel head via a bad seal on the heater plug (when I swapped heads I sprayed carb cleaner on the inside of that seal and it easily passed thru) but I had no detectable (other than a slight diesel smell on a "q" tip inserted into the outside of the heater plug recess) fuel leak.

Tulmaster · **Posted:** Thu Apr 26, 2012 10:46 pm

I have been having similar problems with my 05 2.8 crd. I have been running the gamut but still have not solved the issue. I have posted the questions on other thread regarding it. However regarding the filter head and an add on pump, I chose an inline electric carried by napa. I can get the part number, but comes with all the hardware. There are two versions, one is rated at about 4psi and the other is rated at 10psi. I ran the hot lead to the hot lead of the fuel heater as I did not need the heater. I replaced the filter head with a marine aftermarket also carried by napa which bolts on the standard bolts on the firewall. The fuel pump I mounted on one of the same bolts atop the filter head. I also fitted in a pressure gauge and used a radiator drain valve on the outlet side as a air bleed screw. The gauge was from napa also for less than 10, pump was 55 and filter head kit was 30. So with misc. hoses and fittings the conversion ran about $110. I hope this helps

Mark

Herk · **Posted:** Fri Jun 15, 2012 10:15 am

Well the crank case sensor fixed the problem. Drove it for the last two weeks with no issues.

Stalling all the time

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