Limp mode?

click23 · **Joined:** Thu May 11, 2006 9:22 am **Posts:** 309

On the way to the dealer it goes into limp mode again. This is a different dealer, took it here because it is much closer to my wifes work. I let them know every thing that had happened and it was a CRD Llibby. After waiting for about 5 minutes, the ticket writer comes back and tells me they can't work on it because another dealer had worked on it, and the part were under warranty from them and their tech did not have the tools to fix it. Does any one else smell that??

So I pull out of the lot and limp mode againt. And the trans temp light comes on. I had to have it towed 60 miles to the fisrt dealer.

UFO · **Posted:** Fri Dec 19, 2008 1:19 pm

click23 wrote:

MrMopar64, why would going into limp mode not cause a CEL? I would think that anything serious enough for a limp mode would be serious enough for a CEL

There is a sensor that will trip the engine codes for a "fuel leak". My CEL did not come on until it happened 3 three times.

nursecosmo · **Posted:** Fri Dec 19, 2008 3:37 pm

MrMopar64 wrote:

onthehunt wrote:

Quote:

When I get time I will pull the Quote out of "Diesel-Engine Management by Bosch 4th Edition" pointing out that the Common Rail System REQUIRES a SUPPLY PUMP. Chrysler was smoking crack when they thought they can suck fuel out of the tank with out air leaks.
As stated before,"you can not defy the Laws of Physics"

Since the fuel system is made by Bosch I would assume they know what they're doing. You people really need to quit with the mandatory lift pump crap. See the obscene photo thread with the guy from Texas with over 100,000 milesSTOCK and zero problems. Far too many people are running a stock fuel system and have zero problems for you to claim the stock fuel system inadequate.

I would have to agree with this quote. Out of the thousands of KJ diesels that were sold both in the US and Europe with this exact configuration, the percentage of people that have had issues is smaller than you think with the "majority" of people here that have problems representing a small faction of owners, and of the people who have seen to it to retrofit the limp pump, there's not a 100% success rate of curing the ailments.

The other quote shown above regarding the Bosch handbook - that's not entirely true. For decades, engines with mechanical fuel pumps sucked fuel from the tank to the engine and it worked just fine. The application on the KJ was specifically designed the way it is by Bosch to be a self-lifting system. The biggest misconception is that the fuel head is not∫ˆ a Bosch component, instead made by a company called Ufi Filters, and the design of the filter head was constrained by factors set forth by the customer. The Bosch book is right in that a supply pump is required, but you must remember that the supply pump on this engine isn't electrical - and that's okay.

It is true that many Bosch systems have had suck through filters for decades without problems but none of them have ever had to suck through a highly restrictive 2 micron filter placed at the highest point in the fuel system.

onthehunt: it is true that many folks have not had problems yet with their filters but many folks have, just as some have not had to replace the EGR yet but many have. A high enough percentage of these problems have occurred to make the positive declaration that these are definitely problem areas with our CRD's and should be the first place to look when these symptoms are encountered. As click has already stated he has excessive air in the system which cannot be purged so chalk another one up to Chrysler design failure.

Those who have not had any problems yet with their fuel system are very fortunate, but anyone who makes the declaration that the fuel system on the CRD is an adequate design is not living in reality. As W2D said DCX was smoking crack when they came up with this one.

click23 · **Joined:** Thu May 11, 2006 9:22 am **Posts:** 309

Just called the dealer, the tech was on a test drive with another car, but the service writer that I spoke to thought he heard the tech and the service manager talking about ordering an new transmission.

nursecosmo · **Posted:** Fri Dec 19, 2008 6:02 pm

Well maybe it is a good thing that you are having this mystery problem because when you are done you will have a new Jeep. :twisted:

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Quote:

and of the people who have seen to it to retrofit the limp pump, there's not a 100% success rate of curing the ailments.

I'm not sure how you collected and measured the data accurately enough to make that statement or what specific range of ailments you are referring to, but I'd be interested in an explanation of the metrics and analysis you utilized. And while we're talking success rates, what's Chrysler success rate in curing the ailments for those who have it?

Or is this another blooper advisory on the use of auxiliary lift pumps set as low as 2 psi causing excessive black smoke, loping idle quality and other gremlins on the R428 engine? :-)

One fact is indisputable - you can make it home just fine with a small air leak with a low pressure lift pump on the Liberty CRD, that on the vacuum system will leave you stranded on the side of the road. That's an ailment that is cured by using a pressurized fuel supply line instead of a vacuum system with 2 to 10 micron filtration. And if you research it, you'll find the amount of vacuum it takes to breach the vapor point of D2 within the CRD fuel supply line to the CP3 pump. It's attainable, and even more so at higher fuel temperatures and that's before the air leaks caused by burning fuel heaters and highest point placement of the fuel head.

This ailment isn't unique to the Liberty CRD - I found the same hard start issues being discussed on a GMC diesel forum dating back to 2001, when hard starting and large air leak codes stranded owners. Similar style integrated CP3 lift pump, same vacuum fuel supply system. Surprisingly, when a few of them added FASS, AirDog or Kennedy lift pumps, those problems disappeared. When one of them contacted GM about how an auxiliary lift pump fixed his issue, they responded with "No additional lift pump in addition to the CP3 lift pump is necessary or desirable." Dejavou. What else are they going to say?

Whether fuel cavitation causes driveline vibration is an issue I'll leave to the Chrysler engineering team. I'm sure they have a fix waiting, just ready to go, needing only $4 billion of bailout money to get it out the door. It's next to the bin where the prototype of the heavy duty diesel rated torque converter for the Liberty CRD is sitting.

danoid · **Posted:** Fri Dec 19, 2008 11:26 pm

Rather then unplugging the fuel heater, pull the relay for the fuel heater, pull the cover off of it, rip the armature out, put the cover back on and put the relay back in. There's a possibility of introducing a leak with the electrical connector unplugged.

click23 · **Joined:** Thu May 11, 2006 9:22 am **Posts:** 309

Just spoke to the dealer again, the new transmission is on order. 3-5 days for it to come in and another day or two to install it. Still no word on what caused the problem, I just hope this gets it fixed.

ATXKJ · **Posted:** Mon Dec 22, 2008 8:47 pm

FYI - I still believe that the total air in fuel/limp mode issue - is not the design of the system - the design is sound - but it is not robust to manufacturing problems.

The failure is in the manufacture of the fuel head - specifically the insert molding of the heater into the plastic puc.

On a small percentage of CRDs - they came from the factory with leaks - these folks had problems from day 1 - dealers couldn't fix them - several were lemon law - buyback. But most CRDs worked fine.

There's a second set - where the molding on the fuel head was marginal - they worked initially - but the heat from the fuel heater - broke down the surrounding plastic - causing leaks.

And then there are still original, stock CRDs - with no problems.

However - if you're in one of the groups with air leaks - the dealers are clueless - they can't fix them - there's no code and they can't solve the problem, without doing a 'shotgun' replace everything in the fuel system - which includes the fuel head - which fixes the problem.

but the problem is the manufacture of the fuel heads - not the design.

The lift pumps - work by overwhelming the leak - they work

Racor fuel heads work by eliminating the molded puc - they work

The newest redesigned fuel heads from Chrysler appear to work
(we only have a couple of people with them but they haven't mentioned problems)

any theory that starts with this as a design problem - has to also account for the systems that work - because they exist.

UFO · **Posted:** Mon Dec 22, 2008 9:52 pm

I respectfully disagree. Even with a good fuel head and no leaks whatsoever, the high point in the fuel system will still trap air. The vacuum will pull dissolved air from the fuel and it will pool at the filter head. Volkswagen and Mercedes both recognize this, and have a return line at the high spot to purge the air back to the tank. Some CRDs may not see this issue immediately, but far too many have, and the results are clear. This is a design problem, and Chrysler dropped the ball.

nursecosmo · **Posted:** Tue Dec 23, 2008 1:51 am

UFO wrote:

I respectfully disagree. Even with a good fuel head and no leaks whatsoever, the high point in the fuel system will still trap air. The vacuum will pull dissolved air from the fuel and it will pool at the filter head. Volkswagen and Mercedes both recognize this, and have a return line at the high spot to purge the air back to the tank. Some CRDs may not see this issue immediately, but far too many have, and the results are clear. This is a design problem, and Chrysler dropped the ball.

Yes, if it were not a problem Chrysler would not have put lift pumps on the new model Jeeps. according to this poll 68% of owners have had air problems while 28% report no air yet. http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=38383 That is a strong indication that the design is flawed. It is not a manufacturing problem in all cases it is a design flaw. I do not have an air leak in my filter but I can consistently get air to be sucked out of solution and collect in the filter without the LP to keep it pressurized, especially in hot weather.

warp2diesel · **Posted:** Tue Dec 23, 2008 6:44 am

On page 82 of the Bosch, "Diesel-Engine Management" 4th edition, the illustration for the Typical Common Rail System, they show a lift pump. On the next page, 83 here is what they print on the "Fuel-Supply Pump" paragraph; "The fuel-supply pump draws fuel from the fuel tank and conveys it continuously to the high-pressure pump. The fuel pump is integrated in the high-pressure pump on axial-piston and radial-piston distributor pumps, and in a few instances in common-rail systems."

The Chrysler Bean Counter and or Bosch Salesman read, "and in a few instances in common-rail systems" and ran with it throwing all common sense and the laws of physics into the dumpster to cut costs. Bosch put that statement into the sentence so that they would be covered if they had a manufacturer who would put the fuel tank higher than the fuel pump like the older farm tractors and stand alone power units. Most newer farm tractors and stand alone power units put the fuel tanks lower so that you don't need a cat walk or man lift to fuel up. Since our CRDs have the fuel tank lower than the CP3 high pressure pump , "and in a few instances in common-rail systems" is not suitable for our application. If I were on a Jury, I would not vote for an acquittal for the charges of having a design flaw.
Our poll reflects as pointed out by nursecosmo that CRD owners who participated in the poll have had a 68% failure rate in respect to air bleeding into the fuel system. An acceptable failure rate/warranty rate for most manufactures is between 1% and 2%. The company I work for is working on getting the Failure/Warranty Rate below 1% as are many other companies.

With only 28% experiencing no problems, Chrysler gets a Failing grade of F :!:

Can we expect a recall on this with Government organizations like the totally worthless NTSB who could not find a rock in a quarry, and a group of Hedge Fund Investors who bough Chrysler who know less on how to run an automotive company than a group of children playing marbles, fat chance.

When I determined Chrysler had a flawed design and remembered all the damaged pumps I have seen throughout my years and not wanting to shell out for a CP3 pump down the road, I installed my lift pump. After I installed my lift pump, my filter head leaked fuel at the heater plug and the dealer replaced it under warranty. After the lift pump was installed and the filter head replaced, I noticed that the engine did not act weak at higher RPMs when I had to merge into traffic. Also I noticed that I no longer got the gray haze behind me when I had to accelerate hard to merge into traffic. What I did before I installed the lift pump was try to keep the engine below 2500RPM so it would not start stumbling and loosing power. What was the cause, air in the fuel system being sucked into the CP3 pump when the demand for fuel increased at higher RPM.

ATXKJ · **Posted:** Tue Dec 23, 2008 9:42 am

you can't get valid statistics using LOST data.
Internet forums are not statically valid cross sections of the general population.

in fact you could easily argue that people join forums looking for answers to a problem
and therefore with thousands of CRDs sold and only a few hundred at most on the forum -
the CRD would be overwhelmingly problem free.

The only way to get real data - would be to get some samples of Chrysler's warranty statistics

I never meant to imply that this was a good design - good designs are tolerant of all kinds of problems and still work
this is a marginal setup - if fails if it has any problems - but if all the pieces are good - it will work.
(which is what the bean counters were looking at when they cut the lift pump out of the budget.)

however from a reality standpoint - I added the lift pump and when I'm out of warranty I'm changing to a Racor
I think those are reasonable precautions. I expect that systems in operation will have problems.

(and the company I work for is looking at failures in the part per million range - but hey we're not big enough for the Government to bail us out.)

BlackLibertyCRD · **Posted:** Tue Dec 23, 2008 9:52 am

Chrysler's warranty statistics = problem not found :evil:

click23 · **Joined:** Thu May 11, 2006 9:22 am **Posts:** 309

Transmission is still not in, hopefully today or tomorrow but who knows.

click23 · **Joined:** Thu May 11, 2006 9:22 am **Posts:** 309

Well we finally get the jeep back yesterday afternoon. The torque converter got so hot that it actually blued the TC housing, what cause the whole thing, they have no idea. I just know that I did not have any transmission problems until they replace the ECM. I am going to call Chrysler to see if they can help me out on my rental car bill. I have an extended warranty, but it only covers the first 5 days, and it was in the shop for 19.5 days, I believe the transmissions was ordered the second day in, and it was delayed a few times.

nursecosmo · **Posted:** Thu Jan 08, 2009 12:26 pm

Man I'm sorry to hear about that Click. Look on the bright side though, you have the only new CRD sold within the US in three years.

Limp mode?

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