It is my belief that the fuel system problem experienced by some owners is not a “design” flaw, but rather a “mechanical” error found in those cars which display the problem. If the problem were due to a design issue then “all” owners would have experienced the issue. Clearly this is not the case. I suspect that the problem is related to poor manufacture and/or installation of the fuel lines/heads which results in poor sealing of the system due to gasket, or fitting failure/misalignment. The result being that the system, under vacuum rather than pressure as has been noted, sucks in air and causes the engine to be starved of fuel.

Logic would dictate that the problem has to be “unique” to those vehicles which display the problem, or else all would have reported the issue. The percentage of owners noting the difficulty may be high, but it is not 100%. I am an original owner with over 70k miles at present. I have started/driven the Jeep in temps ranging from -20 to over 100F without issue. I get a general mpg of 25+/- and have approached 30 mpg on occasion in hot weather. My car is bone stock and has had no fuel issues (except a minor slow start due to dirty filter) in the entire time I have owned it. I normally change my filter at 25 thousand miles and have only had to prime the system after filter change. I do not use any fuel additives except some anti-gel in very cold weather.

I am not an engineer, mechanic, or gear head, but just a lowly chemist. I do understand the principal of “Occam’s razor” which has been understood by both scientists and philosophers since the 1300s. Basically the theory states that the simplest answer to a problem is the most correct. I suspect that the simple answer is mechanical failure, not design flaw. If I had the problem I would be looking at the fittings and couplings FIRST and eliminate those as the cause before looking for more complicated solutions.

Just my 2 cents. Oh and by the way, kudos to GDE for simple, logical, and non-emotional solutions.

I have a post up "Jeep Still Stalling" and after a few posts here, I am convinced my filter head is getting air in it. It only happens now in the summer after some driving and a good park for about an hour or more. Just enough to get a good "heat soak".
Sure enough it will start, but when I'm about to drive it will stall or feel like it's about to stall. Actually it won't move, feels like the parking brake is on. The turbo spools and the truck barley moves. Ranger1, I am convinced after reading your post that this is my issue.

It will not stall in park or neutral. It doesn't seem to misfire.
I step on the go pedal and you hear the turbo spool but she won't move.
That's when I put it in park and rev the motor. Drop back in gear and it goes.
My thoughts have been egr. But have the segr now so that's eliminated.
Then I thought fuel. But I have the new head unit and the pump so I am still scratching my head.
Cat, you think it could be tranny?

By this reasoning, none of the common issues encountered by the average CRD owner are "design flaws". The recalled ball joints must be due to manufacturing variance, not due to a design flaw using an undersized weight bearing component in a heavy SUV because not a full 100% of owners have had to replace them. The sticky EGRs must be due to improper installation at the factory, not because of all of that thick black crap stuck in the perfectly designed part. The torque converter replacements performed by DCX must have been done because some tech putting them together at the factory thought that the instructions said plastic stator and not steel stator. It obviously couldn't have been because of design flaws, because not 100% of owners have had to replace their Torque converters.

Ask the airline industry what an "acceptable" rate of failure is for a particular part to be considered to have a design flaw. The answer will often be just one.

I'm not sure how you are differentiating between "mechanical failure" and "design flaw". Under normal operating conditions, If it fails when it shouldn't, or well before it's expected lifespan, it is a design flaw.

Another case of when something sucks it can fail.

It will not stall in park or neutral. It doesn't seem to misfire.
I step on the go pedal and you hear the turbo spool but she won't move.
That's when I put it in park and rev the motor. Drop back in gear and it goes.
My thoughts have been egr. But have the segr now so that's eliminated.
Then I thought fuel. But I have the new head unit and the pump so I am still scratching my head.
Cat, you think it could be tranny?

Finally! Someone that proves I'm not a total nut.

Working on it. Not ready to announce.

I think the problem is in the valve-body, causing the TCC to lock prematurely - be nice to get some hands-on with that KJ and a scantool - maybe the "problem" could be worked to our advantage, with TCC lock on demand - would require the Hemi-vertor.

Minor shift-point variations are resulted from actual tire diameter, incl tire pressure, and the programmed tire size\diameter in computer - mine is in OD well B4 TCC lock at 54mph,and stays in lock till just below 52mph - I have Suncoast\Transgo and 2.55's and reset the computer for tire diameter, as 2.55's are not listed

I anticipate similar upgraded performance from the oem-stock Hemi TC in normal street usage - the Suncoast Hemi TC is necessary for drag-racing, but not for the minor hauling\towing capabilities of this small swb chassis - all TC dimensions are identical - all 545RFE input parts are identical p\n's - only slight concern I have is whether the Hemi convertor clutch was upgraded 11\05 along with the KJ clutch - it may not matter, as the Hemi-vertor has lower stall by ~400rpm so there would not be clutch in\out chatter as with the hi-stall KJ-vertor - will post results soon - stay tuned................