New Issue with CRD

cocojo · **Posted:** Tue Dec 05, 2006 12:15 pm

When I drive on the highway doing a steady 70mph, I will be going along fine then the vehicle will buck for a split second. It will do it two or three times I will back off the pedal and it will be ok until it does it again. Is this part of the torque converted problem or some type of misfire or EGR issue?

DZL_LOU · **Posted:** Tue Dec 05, 2006 12:39 pm

cocojo wrote:

When I drive on the highway doing a steady 70mph, I will be going along fine then the vehicle will buck for a split second. It will do it two or three times I will back off the pedal and it will be ok until it does it again. Is this part of the torque converted problem or some type of misfire or EGR issue?

This is the classic "transmission shudder" that typically occurs when your accelerating upto say 70mph. My transmission was replaced and TCM reflashed at 25K miles so I really don't experience this anymore. However, at the time there were several posts debating if this was a fuel delivery issue or if this was a transmission issue.

Spowers · **Posted:** Tue Dec 05, 2006 12:56 pm

If you are at speed and been there for a while, it sounds more like a fuel interupt problem

If you were accelerating up to speed, then backed off, that is my tranny shudder problem. But otheres may have experienced differnt situations.

greiswig · **Posted:** Tue Dec 05, 2006 1:08 pm

cocojo wrote:

When I drive on the highway doing a steady 70mph, I will be going along fine then the vehicle will buck for a split second. It will do it two or three times I will back off the pedal and it will be ok until it does it again. Is this part of the torque converted problem or some type of misfire or EGR issue?

Try bleeding the fuel system at the filter, and see if there's air in it. That could cause what you're experiencing. If it is there, it may return rapidly, so don't expect bleeding to fix the issue. I'm putting a lift pump in mine.

MrMopar64 · **Posted:** Tue Dec 05, 2006 1:16 pm

greiswig wrote:

... I'm putting a lift pump in mine.

Don't put a lift pump in the CRD KJ!!! It will mess up the fuel delivery system and will not fuction properly. It will misfire horribly and smoke humongous clouds of black smoke. The specific CP3 pump used on these engines has a low-side suction built in and the lift pump will throw off how it's calibrated.

cocojo · **Posted:** Tue Dec 05, 2006 1:21 pm

I do have the 55 shudder that I know. You can feel the TC locked up. This other issue is when I am at a constant speed for a while, then I feel a buck. Just for a split second. My wife was in the vehicle when it happened and she felt it and made comment about it. It did it two and three times one right after another. I back off the pedal and brought the speed up again and it stopped. Lets see what happens with the new TC after tuesday. I will tell the service dealer about it though. Will the CRD's ever be right? I use Shell fuel and power service every fill up.

retmil46 · **Posted:** Tue Dec 05, 2006 1:40 pm

MrMopar64 wrote:

Don't put a lift pump in the CRD KJ!!! It will mess up the fuel delivery system and will not fuction properly. It will misfire horribly and smoke humongous clouds of black smoke. The specific CP3 pump used on these engines has a low-side suction built in and the lift pump will throw off how it's calibrated.

Can you be more specific? Just how would this throw off the calibration? From what I've read in the FSM, the low pressure supply pump is nothing more than a mechanical gear pump, with no tie-in to the electronics affecting the high pressure rail side. How would a centrifugal pump putting out 1 to 4 psi between the fuel tank and installed filter affect this?

groucho · **Posted:** Tue Dec 05, 2006 2:16 pm

It has been my experience that when I have had a fuel interruption (diesel) at road speed there has been an accompaning BANG as in a combo of driveline components, etc. That was pump failure, although a momentary failure, but repeated infrequently.

With the CRD could it could be several things. It is known that many of the transmissions are deficient in operation. Software is screwed up or has been. The emissions control system is micky mouse and frequently fails. But, you can be sure that the plugs ain't fouled!

I think some of the mess is caused by the wiring harness feeding into wires controllling the computers, etc. This was a serious problem on Dodge Cummins and Mechanics Illustrated found a similar problem with a CRD they had.

IndyCRD · **Posted:** Tue Dec 05, 2006 2:59 pm

cocojo wrote:

When I drive on the highway doing a steady 70mph, I will be going along fine then the vehicle will buck for a split second. It will do it two or three times I will back off the pedal and it will be ok until it does it again. Is this part of the torque converted problem or some type of misfire or EGR issue?

It's funny that you brought this up. Just this week I have had the same thing happen. In the past, I have had an occasional shudder around 55 mph and an occasional clunk around 35 mph (when the trans fluid was really low...dealer's fault, btw). Never before this week have I had the Jeep start jerking around on me when I'm going 70-75 mph. It has done it three times this week.

Maybe it has something to do with it being very cold outside. Here in IN it has been extra chilly starting just this week. It could just be a coincidence that it happened to both of us at the same time, also. Who knows.

oldnavy · **Posted:** Tue Dec 05, 2006 4:26 pm

Sounds more like fuel interuption to me or possible anti shudder valve (FCV) doing a partial closing or closing then opening but that is rather unlikely.

My first inspection would be the fuel lines at the filter that might not be tight allowing air into the system or loose filter at the head, then check for contanimated fuel.

If you have been using biodiesel you could have a growing problem in your tank and lines due to bacteria growth and need to be biociced and cleaned. However it would most likely be water contaminated.

cocojo · **Posted:** Tue Dec 05, 2006 4:31 pm

There is only 3800 miles on my jeep. I would think it's a little soon for some of these problems. It's a definite skip or delay. I still think it's the tc somehow. Everything with this vehicle seems to be tranny related except the EGR's.

Jeger · **Posted:** Tue Dec 05, 2006 4:40 pm

I am going to second the motion for priming your system, pay attention when you do and look/listen for air escaping.

RAF 3829 · **Posted:** Tue Dec 05, 2006 5:47 pm

I've noticed that bucking too, but it doesn't happen all the time. It's usually when I'm driving, doesn't do it when the wife's driving.

BlackLibertyCRD · **Posted:** Tue Dec 05, 2006 5:55 pm

Jeger wrote:

I am going to second the motion for priming your system, pay attention when you do and look/listen for air escaping.

Same here, I bleed when I have the problem and it go away. I think the fuel system airate back through the return and to suction line in the tank.

DarbyWalters · **Posted:** Tue Dec 05, 2006 6:03 pm

Like Jeger said...push the primer about 4-5 times...wait about 2-3 sseconds and see if any fuel/bubbles show out of one of the sensor wires at the bottom of the fuel filter assembly ( not the bottom of the fuel filter but the housing it screws onto. )

action · **Posted:** Wed Dec 06, 2006 10:46 am

Happens on a very rare occasion to me too. I just press the OD off button momentarilly and press it again to go back into overdrive....shudder goes away and does not come back.

Jeger · **Posted:** Wed Dec 06, 2006 10:52 am

action wrote:

Happens on a very rare occasion to me too. I just press the OD off button momentarilly and press it again to go back into overdrive....shudder goes away and does not come back.

You mean it doesnt come back? Or it just doesnt come back until the next time it does it?

New Issue with CRD

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