loss of power... for a moment?

novacrd · **Joined:** Wed Oct 06, 2010 4:34 pm **Posts:** 13

Today I was on the highway and my libby was running great, I pulled off to get a coffee and it had a huge loss of power and sounded terrible (maybe not running on all cylinders). I was close to a dealer so I limped into their lot. Once there I shut down my jeep and waited a second, turned the key and it started and ran like normal. No warning lights came on at any point and it drove fine for the next two hours of my trip (back on the highway) with no issues. What happened? Should I be worried?

nursecosmo · **Posted:** Sun Mar 06, 2011 11:31 pm

We need more info like how cold was it, when did you last change the fuel filter, where do you live, do you have a lift pump, did it smoke, etc. The most common reasons for the vehicle going into limp mode without tripping a check engine light(what you describe) are either a filter which is plugged or a small air leak in the fuel system. Both will eventually trigger the same trouble code P0093. For some reason which no one understands, some CRDs will go into limp mode but not immediately trip this code.

The next suspect would be a sticky EGR valve.

SargeIndustries · **Posted:** Mon Mar 07, 2011 2:43 am

Mine has done this a couple times. I turned the engine off and restart and everything has been fine. Not sure what the culprit is...

SLS · **Posted:** Mon Mar 07, 2011 1:49 pm

I agree with nursecosmo, need more info.

novacrd · **Joined:** Wed Oct 06, 2010 4:34 pm **Posts:** 13

nursecosmo wrote:

We need more info like how cold was it, when did you last change the fuel filter, where do you live, do you have a lift pump, did it smoke, etc. The most common reasons for the vehicle going into limp mode without tripping a check engine light(what you describe) are either a filter which is plugged or a small air leak in the fuel system. Both will eventually trigger the same trouble code P0093. For some reason which no one understands, some CRDs will go into limp mode but not immediately trip this code.

The next suspect would be a sticky EGR valve.

it was pretty warm (8 degrees C, what that like 48F) no smoke, it began after I drove about an hour so it was good and warmed up. My liberty is stock except for the GDE eco tune. I live in Nova Scotia, Canada. I don't think it was in Limp mode, it wasn't a slight loss of power, it was an all out loss, when I hit the throttle it would only rev to 2000 rpm and was running really rough. Not sure when the fuel filter was changed last, what ever service it's suppost to be done at I guess there are 66000km on it (Most of the work til now has been done by the dealer). if it was an air leak why do you suppose it stopped once restarted? It only lasted for five minutes tops. I didn't get a chance to try it today, but it ran like a top after I shut it down for a second and restarted. I guess I'll have to see if the condition will accure again, I just hate the idea of getting stuck somewhere (a lot of garages aren't open here on the weekend, even my dealer only has a diesel tech on during the week days).

nursecosmo · **Posted:** Tue Mar 08, 2011 3:00 pm

novacrd wrote:

it was pretty warm (8 degrees C, what that like 48F) no smoke, it began after I drove about an hour so it was good and warmed up. My liberty is stock except for the GDE eco tune. I live in Nova Scotia, Canada. I don't think it was in Limp mode, it wasn't a slight loss of power, it was an all out loss, when I hit the throttle it would only rev to 2000 rpm and was running really rough. Not sure when the fuel filter was changed last, what ever service it's suppost to be done at I guess there are 66000km on it (Most of the work til now has been done by the dealer). if it was an air leak why do you suppose it stopped once restarted? It only lasted for five minutes tops. I didn't get a chance to try it today, but it ran like a top after I shut it down for a second and restarted. I guess I'll have to see if the condition will accure again, I just hate the idea of getting stuck somewhere (a lot of garages aren't open here on the weekend, even my dealer only has a diesel tech on during the week days).

It is almost certainly the fuel filter. Yes, what you described sounds like the limp mode without a CEL. If you don't know when the last time the filter was changed, it's time to change it.

BobFarley · **Posted:** Wed Mar 16, 2011 10:18 am

So I've been experiencing the same loss of power described below...infrequent usually in the morning before it's warmed up. Seems like it would only occur after/during hard acceleration. Thinking it was related to the fuel filter I recently changed it, and much to my surprise a found the small filter O ring was chewed up and half sucked into the filter. After changing I noticed an improvement but days later had another recurrence. Usually if I stopped let 'er idle for a second and take off again I have no problems.

Today while running down the interstate about 70 I punched it down to pass (and the A'hole accelerated so I had to put it all the way to the floor and hold it for a minute or two). When I let up no power and decelerated (not by choice) to about 60 and hit the next exit. No luck this time... I didn't restart but still no power when I took off again after idling. The CRD was at operating temp, the outside temp was 40 degrees Fahrenheit, no noticeable smoke, recent fuel filter, no other mods (factory set up). This past summer I had problems with it not starting and had to prime it a few times mostly in hot weather after running and shutting off for a short time. I understand the air in fuel problem and plan on adding the lift pump this summer but don't see how that could be related to my current problem especially if I'm not seeing white smoke.

I replaced the CAC to INTAKE hose about a year ago and bought but haven't installed the Turbo to CAC (hot) hose (small dia.). If it was puffing smoke I'd definitely think it was one of the Charge Air hoses, but as I said no noticeable smoke black or white.

Any advice is greatly appreciated! This forum has been a big help to me in the past so good work guys.

obthomas · **Joined:** Tue Nov 30, 2010 2:29 pm **Posts:** 28

My Liberty has done exactly what you guys are describing in the past. Once I stopped and restarted it was fine. Turned out that my origional red top battery had a bad cell but was somehow strong enough to start the engine but not strong enough to run all the engine electronics. Put a new battery in and never had this problem again.

BobFarley · **Posted:** Thu Mar 17, 2011 6:46 pm

obthomas wrote:

My Liberty has done exactly what you guys are describing in the past. Once I stopped and restarted it was fine. Turned out that my origional red top battery had a bad cell but was somehow strong enough to start the engine but not strong enough to run all the engine electronics. Put a new battery in and never had this problem again.

So I ran this by a buddy who owns an Auto Parts Store and he said that about a year ago his mom's Jeep Grand was dying after start up and you had to hold your foot in the pedal a little to get it to restart...turns out the problem there was battery related. Apparently had enough power to start but then would only register 9 volts so the computer would go nuts. I hate to drop $160 bucks in a new red top but I'm beginning to think that might be the culprit. Its odd that it will just go into limp mode at times (usually after hard acceleration) but I'm thinking maybe it's because the sensors or computer aren't getting the right voltage and showing a false read. I recently cleared the codes and do recall a P0069 which is barometric pressure difference (I think but would have to double check the service manual). I've had a check engine light intermittently for a couple of months but just contributed it to the MAF or MAP sensor needing a good cleaning. Anybody else think it's crazy that this could all be caused by the battery? No offense obthomas but how can a bad battery be causing the computer to misread sensors or act abnormally? One would think that the alternator would be able to keep up the voltage required for running and also charge the battery.

Any thoughts?

BobFarley · **Posted:** Wed Mar 23, 2011 1:04 pm

OK so I was pretty skeptical about the problem being battery related but I guess I'll have to eat my words. New battery and the problem appears to be solved. I was running the factory Red Top Optima so being 5-6 years old I guess it lived a full life.

So in summary if you have the above mentioned problem and have changed your fuel filter and don't notice any significant amount white or black smoke and are running an old battery...the battery could most likely be the cause of all your problems.

loss of power... for a moment?

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