Torque Converter or Dirty Fuel Filter

snowman_crd · **Posted:** Thu Dec 10, 2009 10:56 am

After doing some research here on the forum, I think have been able to narrow my issue down to a torque converter going, or a dirty fuel filter.

When I first let off the brake from a complete stop, and start to accelerate in a conservative matter the Libby hesitates, sputters a bit. If I accelerate a little more aggressively it doesn't seem to hesitate at all. If I continue to accelerate conservatively it will smooth out until I hit about 15mph and then sputters again until I give it more throttle and get past 25mph.

I just bought the Libby a week or two ago, and have now way of knowing how old the fuel filter is and I have ran two tanks of B10 through her, so picked up a fuel filter and plan to install it this weekend. Obviously, the cheaper of the fixes... I would greatly appreciate and insight and help anyone could provide. I thank you in advance!

dgeist · **Posted:** Thu Dec 10, 2009 11:22 am

Since it's new to you (and also since you're running Bio in it where it might not have been before), the fuel filter change is a relatively inexpensive item you should probably do anyway. Other than that, you can check for air in fuel by bleeding with the on-head pump (procedure is documented in numerous threads in the CRD sections). The issue does sound like fuel starvation, though, and air in the head or a clogged filter are the most common causes of that. Don't wait too long to work in it, though. Consistent fuel supply helps cool/lubricate the high-pressure pump, etc.

Dan

danoid · **Posted:** Thu Dec 10, 2009 12:29 pm

The two most common 'torque converter' issues are actually pump/filter issues. *EDIT* that's transmission pump and filter - not fuel

The first is torque converter drainback. There's air in the converter, so it can't transfer torque from the crankshaft to the transmission. If you parked the truck hot and let it cool off, on restart the engine will rev too high and there's no vehicle go. This one is usually fixed by new transmission filters.

The second is low pump pressure not allowing the torque converter to unlock. As you come to a stop it feels like you're driving a manual and forgot to push in the clutch. Stand on the brakes and leave the transmission in Drive and you'll stall the engine. Shift to Neutral and you can stop just fine.

The third, less common, failure is a complete grenading of the damper. This sends debris everywhere ATF goes and it's only sure fix is a new transmission, transmission cooler, and cooler lines.

Since your symptoms don't match these, continue investigating the fuel starvation.

snowman_crd · **Posted:** Thu Dec 10, 2009 2:16 pm

Thank you both for your responses. I will replace the fuel filter tomorrow and troubleshoot from there. Thank you again.

snowman_crd · **Posted:** Sat Dec 12, 2009 10:28 am

I changed the fuel filter this morning... and it seems to improve the problem...but it did not solve that problem. Regardless, the filter was in definite need of changing.

I guess my next step is RACOR??? Or a lift pump???

Joe Romas · **Posted:** Sat Dec 12, 2009 12:15 pm

If you want to troubleshoot your problem put a clear section of hose (temporarly) on both the input and output of the fuel head and look for air bubbles. I suspect you'll see them on the INPUT of the filter. If you put on a lift pump it should be as low as possible in the system. I choose an intank Cummins pump. It cured my problems that are similiar to yours. Some claim it's only a band-aid fix that covers the problem. The real problem in my mind getting the dealer to go further then "can not duplicate" :shock:

Early on in the product life of the US CRD's some dealers cured the problem by replacing the fuel lines from the tank. But step one was convincing my dealer there was really a problem with my brand new CRD that first occured on my very first mile of ownership :cry:

I sure dislike buying new vehicles and paying new vehicle prices for that simple reason

I much prefer buying a spotless 00 XJ Classic for $4k with no warranty at all like I did last Feburary and taking care of problems myself

I now have a fantastic ready for the wife to go anywhere XJ for a total of under $5k

ATXKJ · **Posted:** Sat Dec 12, 2009 3:34 pm

Pull the heater plug and see if it's leaking - that's the most common point
it's the plug on the right
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?p=381161#381161

and the link is the new filter head design - it should fix the leak

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

Try running a test with the mass air flow sensor disconnected. The hestitation could be caused by a partially clogged EGR system. With the MAF unplugged the EGR is off. What is the outside temps when the issue is more prevalent?

snowman_crd · **Posted:** Sat Dec 12, 2009 6:13 pm

I did check the heater plug and there was no leakage. So it must be coming from elsewhere...

I will try the clear tube thing and see what happens there. I have a strong feeling that there is a lift pump in my future. What are the ups and downs of the options available?

Torque Converter or Dirty Fuel Filter

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