We have been following several of the topics discussed in the forum. We wanted to highlight a few items below:

1. Removing the catalyst. The catalyst on the KJ CRD is an oxidation cat designed to reduce the HC and CO emissions. The efficiency is very high with about 90% of the HC and CO being converted to harmless gases...if you consider CO2 harmless as the EPA does. Most are familiar with carbon monoxide (CO) and its potential to cause acute respiratory issues and death in a non-ventilated area. Hydrocarbon (HC) is the leading factor in the smell of diesel exhaust and is a factor contributing to smog and excessive ozone production around big cities. We have tested the KJ with and without a cat installed and found no difference in fuel economy, performance or drive ability. The main difference is the pungent smell of the exhaust with the cat removed. Without a cat the exhaust is prone to have a bluish tinge to it and will leave a trail if doing city driving. This is just not a good thing for the people driving behind you and also leads to poor perception of diesel vehicles in general. In normal conditions the cat will "light off" (start converting gases) within 200 seconds of driving as soon as the brick reaches about 200 C, after this point the cat will continue to function unless you are driving down a mountain grade for an extended period, in this case the exhaust temps will drop to about 100-130 C and conversion stops. This is why you may see diesel vehicles making blue smoke going down mountains. The catalyst does not do much for particulates (PM), maybe a small % adheres to the cells inside the cat and they tend to blow off under hard accels.

2. Lift pump/random limp mode without CEL. The KJ CRD was designed from the factory with a positive displacement lift pump attached to the high pressure pump on the engine. The pump is located about 2 feet below the fuel filter assembly so air collects inside the filter and does not travel down the supply line to the pump. Typically this system will function without issue throughout the life of the vehicle, however the fuel heater connector terminals are too small and cause very high temps in the circuit promting melting around the connector on the fuel filter head assembly. This will allow air injestion into the head assembly, which can kill the prime on the fuel system and make starting very difficult without priming the filter head each time. There is a service fix for the fuel heater issue. Sometimes there is a random fuel pressure fault that puts the vehicle in limp-home mode, yet does not turn on the CEL. This fault has been eliminated in the GDE tune and reduces the possibility of having a limp-home condition. An aftermarket lift pump will not do anything for drive ability, performance or fuel economy, it is more of a feel good security feeling we assume. There is a risk with installing a lift pump that always runs, if the fuel heater connector is melted and the system is pressurized, we have seen diesel fuel leaking out around/through the connector. This could increase the potential for an engine bay fire, we have seen smoke coming from the connector when fuel was leaking due to the high temperatures of the wiring. If there is no lift pump fuel, does not leak out the connector as it normally is under a vacuum. we definitely recommend the service fix available through dealers.

3. Cooling fan system. The mechanical fan has very high parasitics and can reduce fuel economy by up to 2 mpg depending on driving style. Running without the mechanical fan is not feasible if the vehicle is loaded or pulling a trailer, the heat load is too great. The electric fan on the KJ CRD is a pusher style and used mainly for cooling the condenser for AC performance. A pusher fan is not very efficient as compared to a puller fan. A pusher fan is located in front of the cooling system and a puller fan is located just behind the cooling system. Ideally, one could remove both fans and install an aftermarket electric puller fan and it would suffice for most situations, minus a heavy trailer in harsh ambient conditions. We are not aware of any electric fan that can pull 5000 cfm (cubic feet minute) of air through the cooling stack. The condenser, CAC and radiator have too much pressure drop for any fan less than about 800 watts of power.

4. Crankcase Ventilation. The CCV does allow very small airborne oil particles to pass through and enter the intake tube. The valving and spring inside the CCV are designed for a specific pressure drop between the crankcase and intake duct to function optimally. We have not tested the Provent system and this is on our to-do list. Adding a secondary oil separator will change the pressure drop across the factory CCV. There may be potential issues with this and that is why we want to test it. If the pressure balance is off in a negative manner, there may be potential for higher crankcase pressure and this could shorten the life of engine seals.

_________________
Providers of wholly developed aftermarket solutions for the KJ CRD.
(248) 977 - 9531

Thanks, there's a lot of good info there, but I will have to disagree with part of this statement.


I agree it won't do anything for performance or economy, but it definitely helps driveability. Any time you are sucking fuel through a restrictive fuel filter, as in the stock configuration, the pressure drop will cause entrained air to come out of the fuel and accumulate in the filter head. Even if you have every air leak sealed in the tubing. It's not just about leaks in the filter head or tube. When enough air accumulates you'll get rough running and possible no-starts. How many people experience this depends a lot on their driving habits, the state of their fuel filter, and the sensitivity of the driver.

_________________
05CRD: GDE Hot ECU & TCM tunes, Provent, Cat filter, Facet lift pump, TransGo kit, Florida TC, Samcos, stainless brake lines, HDS thermostat, Renegade light bar,
Bilstein adjustables, Al's Gen 4.5 Arms, 235/85-16 Duratracs, DTT rear, Elocker front, EVIC+TPMS, Turbo timer, McNally pillar gauges, Weeks Stage II kit.

The EPA no longer considers CO2 to be a harmless gas. The feds have declared it a dangerous greenhouse gas that it seeks to regulate with "cap and trade" which has passed the house and goes to the Senate.

_________________
2006 CRD http://www.UtahPowderCoatings.com/ http://www.gorecon.com/ I'm kind of a big deal.
RL rear bumper, ARB front bumper, Mile Marker winch, Power Tank, Skids by Mopar & Skid Row, RL Super Skink Sliders, 235/85R16 MTR, Air Flow Snorkel, DTT, 4.10 gears, Frankenlift II, Katskin leather, JL Audio stereo, Rosen video.

I have no opinion on the fans as of yet, and since the lift pump is covered, let me discuss the claims about the catalyst.

Not only does the EPA now consider CO2 to be an evil pollutant (have they checked the output levels of Congress lately?) the contention that it does not harm economy is also subject to debate. I know others have expressed similar opinions, but I personally have experienced a considerable increase in the ability to coast since removing the cat. Before, anytime I took my foot off of the pedal, the vehicle had the feel of light-to-moderate application of a compression brake. This excessive backpressure is not conducive to high economy, it wastes fuel. I wonder if it could harm the turbo by increasing the EGTs from the pressure as well.

Further, I would like to know the quality of fuel you are running, and the health of the engine you are running it in. My CRD did have a very slight acrid odor since the cat removal, but nothing like the similar (and stronger) odor from a gas powered auto that I removed the entire exhaust system while rebuilding it. Moreover, this odor has vanished since I have been running fuel from a different vendor, OR whenever I have operated with biodiesel. I would contend that the low grade fuel has a higher sulfur content and that is what is creating the harsh odor.

Finally... Blue smoke? My CRD does not create blue smoke. Before or after, it has never smoked. My VW Jetta TDI had a similarly designed CCV system that put amounts of oil into the intake, and it would briefly smoke blue on engine startup... Until I installed a CCV filter in it. I do not have a CCV filter on my CRD yet, but I will be installing one soon. I am not concerned about the pressures on the gaskets, unless the ProVent is allowed to completely fill and seal itself off. The minor pressure change of altering the system just moves or removes the VACUUM on the CCV from the pre-turbo intake. If the CCV has positive pressure, then it will continue to vent that pressure. Don't forget, all of those gaskets are under compression from their mating surfaces. It would be no small feat of pressure to pop those out, certainly more than a working Provent would add to the system. For the CRD you are testing with, if it is producing a blue smoke trail, I would first investigate the intake to see how much oil has collected. After that, I would investigate oil consumption or cylinder blow-by, as my CRD exhibits neither of these... But it also does not smoke even after removal of the cat. Blue smoke has ALWAYS meant burning oil in my vehicles. Perhaps there is a leak inside the turbo compressor housing and it is burning into the exhaust?

Wow!! That explains it I guess. I have noticed the same thing. When coming down mountain passes (like 15 minutes or so) at no greater then 40 MPH and using very little if any throttle, the CRD will start to smoke. I have witnessed it a couple of times. One time I got the crap scrared out of me thinking that something was wrong with the engine.

I pulled over, checked it out, it was coming from the exhaust. When I got to the flats, the vehicle stopped smoking. Interesting stuff!!

Thanks for the info.

Just to add a little to this discussion. Warp2diesel has found the stock exhaust system to have up to 4Lbs of back pressure when under high boost. a considerable amount of that is likely from the cat, although I don't think that he conducted any specific tests on cat restriction. I know that I definitely can "hear" more air flowing from my rig since removing the cat, when I stomp it.

Diesel engines, unlike gassers, do not produce appreciable amounts of CO.

Aerosolized Hydrocarbons (VOCs), are considered particulate matter. The larger the size of the PM coming from the exhaust, the less dangerous it is to human health. http://en.wikipedia.org/wiki/Particulates Large diesel particulates also settle out of the air much more quickly than gasoline VOCs, typically not even making it into the smog cycle. An Oxidation catalyst reduces the size of particulates, thus it can be argued that they are more detrimental to the environment than a cat-less exhaust. Just food for thought.





Unfortunately This is not accurate at all. In a poll conducted by myself ~69% of responding members had AIF issues, some even after installing the redesigned filter head. http://www.lostjeeps.com/forum/phpBB3/vie ... t=air+fuel


None of the original heater pucks or redesigned ones have had melting issues when a lift pump was installed, because the element is always submerged in fuel instead of an air bubble. As I recall from a pic of a disassembled heater puck, the burning originated around the element, and worked it's way out to the plug. The redesigned puck has more reinforcement around the plug which prevents melting as quickly, but the element remains the same. Air has also been demonstrated to come from faulty fuel hose connections. A lift pump solves these issues.

Just some more food for thought.

_________________
Manure green 2005 CRD sport4x4, GDE Hot tune, Cat Gut, OE skids, Draw tight hitch, Duramax lift pump, 160K on multiple varieties of fuel, XM radio, Escort live with Redline, fog light mod, GPS, Icom IC7000 all band radio call sign KC9QPF, Grabber AT2s on Soft 8s, FIA grill blanket.

The fuel that we use here is nothing special, just regular D2 from any of the local pumps (BP, Sunoco, Marathon, etc) - pretty much whoever has the lowest price. Everything here is 15ppm low-sulfur fuels. The high sulfur won't cause the stinking smell, but over time the sulfur oxides build up on the surfaces of the catalyst and poison it thus reducing its conversion efficiency and letting more HC and CO through. The old "high" 500ppm sulfur fuels won't poison the cat so much, but running off-road grade diesel or going to a location like South Africa where the sulfur is 3000+ ppm and you'll poison a catalyst in a heartbeat.

As for the blue smoke we see, it's confirmed 100% to by hydrocarbon and not oil. Generally, the engine-out (pre-cat) HC emissions are greater when running EGR and, even more so, with retarded injection timing, thus you'll see a lot more of this behavior with the OEM production calibration versus ours. The vehicles we have for testing only had a slight blueish tint at idle with the catalyst removed but moreso the nauseating smell. No changes to fuel economy nor coastdown times were exhibited with either the '05 or the '06 in our fleet.

_________________
Providers of wholly developed aftermarket solutions for the KJ CRD.
(248) 977 - 9531

is it just me or does most of this (excluding the incorrect info about the lift pump) sound like a rehash from the entire forum?

_________________
Trevor

'05 Limited CRD Inferno Red Pearl Coat
Home made provent installed @ 35443, SEGR installed @ 35466, Fumoto valve @ 37500, trans and transfer case skid, In tank pump installed @ 43500, Suncoast TC & Transgo Shift Kit @ 44730, EGT, Boost, Trans temp gauges, Samco hoses, Rebuilt Trans w/ HD454RFE kit @ 56K, Inmotion Stage 2 @ 56K

Quote:

An aftermarket lift pump will not do anything for drive ability, performance or fuel economy, it is more of a feel good security feeling we assume.

Good grief. This has to the number 1 DumbAzz post of all times on this forum, by people who should know better. Now I'm wondering if any of you drive your own personal diesels on a daily basis, or diesels with a vacuum fuel system in hot summer temps in the hotter regions of the US. It certainly doesn't sound like it. We already know keeping the Bosch fuel head airtight will keep the CRD running. It just doesn't run as well as it can with a pressurized system. In fact, my 2nd Bosch fuel head didn't even leak fuel at the heater port plug until I installed an external lift pump. Then it peed diesel fuel down the side of the filter like a wino under a bridge. Yet, I was running with that leak in the fuel head, and not seeing hard start issues, when clearly air was leaking into the same burned fuel heater pins.

I was willing to support you as long as you kept within the bounds of valid data. This statement is so ludicrous that you defy the collective experience of those running lift pumps on Jeep CRD's and Chevy Duramax's as well as other diesel rigs for decades. There is a big difference between "running" and running well. My CRD "ran" for 2 years before the first Bosch fuel head starting leaking air and quit running without a single MIL or code until after I restarted it. Congratulations on catching up to what owners on this site figured out 2 years ago and issuing a statement of your newfound wisdom about Bosch fuel head leaks.

As a young company specializing in diesel tuning, I would expect you to live, breath and understand the difference running and running in an optimized environment. That statement you made, in the title quoted above, shows me that you do not. It leaves me wondering about the value of your tuning if you don't understand the basic concept of smooth, clean fuel, available at all times, as in dynamic loading of the fuel system, especially under sudden engine loading of the fuel system, as would occur in passing on Interstate driving. Which system would have more fuel ready at the inlet to the CP3, the vacuum system running 10 to 15 inches of negative pressure when the accelerator pedal is suddenly floored, or the pressurized fuel line and filter, running at 4 to 15 psi? Which system would let the CP3 keep the fuel rail pressurized properly in such situations? If you really instrumented the CRD as claimed, and drove it for years while testing, you know which one does. The fact that you don't has me concerned about whether your field testing brought value to your experience.

You made no mention of the poorly designed fuel system, which sometimes leaks vacuum like a sieve as it ages. The same fuel lines and parts are on the gasoline fueled KJ's which operate under pressure. The difference in driving a CRD with a lift pump that slightly pressurizes the CP3 internal lift pump with enough volume and driving a CRD with 10 to 15 inches of vacuum when passing is more than just a "good feeling." You also omitted the fact that entrained air can be kept in that form longer if the pressure is raised or the fuel temperature lowered, or both. Any improvement that can keep the fuel from releasing entrained air is an improvement in driveability.

If you contacted Bosch engineering and they told you that an auxiliary fuel pump is not necessary or recommended for the CP3 with an internal lift pump, be aware that they advised the GM Duramax owners in the exact same manner when they experienced vapor lock with their CP3 based lift pump, through a 3 micron fuel filter circa 2002. Even Baldwin issued an advisory about fuel filter boundry air locks when finer filtration was used with a vacuum fuel system versus a pressurized system. They and others have published pictures of the fuel filter utilization on a vacuum system versus a pressurized system - the vacuum system typically uses the bottom third to one half of the fuel filter, when the same vehicle system was pressurized, the entire fuel filter was utilized, as evidenced by the fuel contamination discoloration on the filter.

Whether you can measure the difference or not is up to your available instrumentation and your experience with diesel fueling systems. I'm beginning to think that in your case, both are somewhat lacking. Your statement I take exception to, based on experience of smoother, crisper throttle response at highway speed, as well as a noticeably quieter engine at 60 mph to 85 mph, stock tuning as measured by an Extech sound meter, model 407750, NIST calibrated. I measured a 2dbA weighted sound reduction at 65 mph over the identical vehicle with no fuel issues, with the same Racor R490 fuel manager installed. Post lift pump, 2 dbA sound reduction. Smoother engine acceleration of having enough fuel for the CP3 to recover fuel rail pressure faster than when drawing a vacuum and overcoming the lag time. If that's a feel good situation, I'll take feel good over your statements any day of the week. Why do owners of Dodge Cummins report a quieter running engine when equipping their diesels with higher quality filtration and higher flow auxiliary lift pumps at highway speeds? Are they just feeling the security or is fuel with less entrained air running better on their vehicles?

Ask any Ford PSD owner with the deadheaded fuel system that experienced the entrained air transitioning to free air inside the fuel channels in the V8 heads because Ford wanted to save the $30 bucks required for the return fuel lines to the tank. On some of the older ford diesel forums, there is a 8 year history of the frustrated owners working on their own dime to solve this issue, including one retired NAV diesel engineer who ran his own Ford diesel shop. This discovery process went on for over a year while Ford continued to deny the issue, even after the owners discovered the entrained air issue, plumbed their own return fuel lines and pressure regulator to keep the fuel flowing at a cooler temperature and higher pressure, to reduce the amount of entrained air moving to free air, as it cooked in the fuel channels inside the ford heads.

Ford's response was to continue to deny any issue existed (similar to what you just did), even going so far as to issue a name for the rougher, louder running, decreased power and fuel economy which accompanied these engines once they heat soaked. Ford called it "Cackle." They said it was normal and didn't hurt anything. Then a former NAV diesel engineer released an email of a meeting that occurred in 2001 between Ford and NAV engine systems engineers. It detailed how NAV diesel fuel systems engineers told them that eliminating the fuel return lines from the heads and deadheading the fuel system would cause performance issues and that NAV had return fuel lines on their heavy duty trucks they built with similar engines. Ford told NAV that if they wanted to continue to do business with them, keep quiet and let the issue die.

When that email came out, there wasn't any question about entrained air causing issues. NAV engineers knew all about it in 2000. The HEUI system they used actually amplified the free air in the fuel issue, even with a separate lift pump, because the fuel sitting in the hot cylinder heads literally boiled the air out of the fuel. It had nowhere to go. When hard starts and no starts began occurring on the 2001 Chevy Duramax diesel trucks using a common rail system with finer filtration, the issue became known all over again, regardless of the fact that the CP3 returned fuel to the tank and didn't dead head. Entrained air transitioning to free air still made it to the CP3 and to the injectors on the Duramax regardless of the position of the fuel filter to the CP3 with integral lift pump. The Duramax owners who had purchased a finer 3 micron Baldwin fuel filter, in an effort to avoid early fuel injector wear out issues, experienced the hard start issues before OEM equipped Duramax owners did as the filters aged. Entrained air caused the Duramax vacuum system problems with hard starts and sometimes no starts. It does on our CRD's as well under the right conditions.

The same set or subset of symptoms are common to both the Ford and Duramax diesel fuel systems. Heat soaked engine bays, and/or low pressure fuel, as in fuel within a vacuum system and a small micron sized fuel filter will cause entrained air to separate at both the filter boundry and areas within the fuel system where heat soak occurs.

The Ford owners ended up with both return lines and a pressure regulator before they finally eliminated their design induced "cackle." Ask AirDog or FASS what happens when fuel with entrained air transitioning to free air is at the injector needle when it opens. You should already know the answer. Cavitation and delayed injection occur.

I have no doubt that the coarser fuel filter used on the CRD is a partial effort to reduce the vacuum level on the fuel lines in hot ambient conditions. It sure wasn't the filtering ability. OldNavy (Walt) tested fuel quality several years ago with George Morrison, an industry leader on fuel cleanliness and filtration, a pioneer well known in the industry, who was influential in getting the CAT 2 filter introduced to the public.

George's test of the fuel quality going into and out of the CRD factory Bosch fuel filter was astounding, but not unknown to him. The fuel quality coming out of the factory filter (relatively new filter) was far worse, several magnitudes of order worse on the ISO cleanliness scale. George's explanation was simple - I'll paraphrase his answer "I've seen this before on cheap paper based filters. When water and debris flow through the filter, it starts to disintegrate and actually contaminates the fuel with cellulose particles and raises the particle count to the moon. It adds trash to the fuel instead of filtering it out when it does this."

Last, but not least, you omitted a major advantage factor in using a lift pump, which permits finer fuel filter use on the CRD, as evidenced by the Cummins study and others, which show common rail systems benefiting from 2 to 5 micron fuel filters with 98.5% to 99% efficiency. The benefit is reduced injector and pump wear. Running a 2 to 3 micron fuel filter with a vacuum system is also a sure formula for hard starts in warm areas of the country, free air in the fuel head and a lagging engine response in hotter climates in a percentage of vehicles. An auxiliary fuel pump will enable the use of such filtering without those negative issues.

Those issues are also identified by some fuel filter manufacturers, and they have posted advisories on them. Those advisories are several years older than our US issue CRD's and this issue is well known it seems by most industry insiders except GDE. Bosch is never going to publicly admit this because they sell a CP3, a good fuel pump AFAIC, with a built in lift pump to help save additional manufacturing costs. To admit it causes additional problems via the vacuum it introduces in the fuel lines kills their advantage in for selling them. Cummins wouldn't settle for it with Bosch on the Dodge ram trucks, and neither should anyone else.

Come on guys, get your facts straight before posting this crap. All it's done is cast doubt on the validity of the other good information you did post.

_________________
2005 LTD CRD RB1 NAV/Htd Leather seats/Amsoil EA filters
SunCoast Mega Trans & Billet TC/PML pan/Aux cooler
Fuel cooler/Lift Pump/10um Pri/Racor R490 2um Sec Fuel Filters
IronMan Lift/Shocks/Provent/Moog ball joints/ V6 Airbox/Fan/Hayden
Cobalt Boost/EGT/Oil/Trans/Volt gauges/Aeroturbine 2525
Yeti Hot Tune/Odessey 65/Samco's/Michelin Defenders

Well, everything they talk about certainly has been mentioned on this forum, but it is nice to have it right in the first page of the forum. Any chance their thread could be made sticky?

They sound like some pretty educated folks, and I for one am:

a)Glad they have come on the scene
b)Really glad they are in my neck of the woods (SE MI)
c)Have a slew of questions I would like to ask them (I'll deal with that slowly over time)

and

d)Will most definitely be getting the GDE tune soon

_________________
2005 CRD Midnight Blue
GDE Tune
Moog Ball Joints
No Exhaust Brake

Winter Diesel Summer Diesel

1-800-PIK-A-BIZ
Everyone's toll free number and then some

I thought diesel cats were different from gasser cats and configured for the
reduction of NOx?
But yeah, if you try to kill yourself by running your CRD in your closed
garage, you will be dissapointed.
And the headache will make you wish you were dead.

So Mr GDE, tell us more about the CCV...

Which is better, the Provent or EHM?

Those oil particles might be very small, but there sure is a whole lot of 'em.
My "home made provent like thingy" traps about 4oz of 'em every 6 months,
and still more make it through.
I just cleaned my MAP sensor and it was oily, but thankfully soot free.

_________________
U.S. Army Retired

Your tune is nothing short of fantastic

I tried a Provent but found the filter media clogged in a short time (maybe 8k miles)

But my CRD had air in the fuel from day one, mile one, actually mile 9 as it had 8 on it when I bought it

If the then DC were on the ball, they would have replaced the fuel lines with revised ones from the tank to the engine but they didn't. They were left over from a pressurized gasoline system.
My dealer gave me the "can not duplicate" and sent me on my way. Yes a vacuum system can work work well. It did on my many past VW diesels. But I'll long remember the day after filling up when I pulled out into a busy 4 lane road and there was nothing there power wise. Just plain dangerous. Yes I feel really good not getting that going to get run over feeling anymore I also think keeping the air out of the filter is keeping it from melting. Yes Chrysler should have replaced all of them under recall instead of buying off the HTHSA

_________________
Atlantic Blue 06 CRD Limited (his)
Joined by a 2000 XJ Classic (hers)

I have removed this post because of unproductive comments.

_________________
Manure green 2005 CRD sport4x4, GDE Hot tune, Cat Gut, OE skids, Draw tight hitch, Duramax lift pump, 160K on multiple varieties of fuel, XM radio, Escort live with Redline, fog light mod, GPS, Icom IC7000 all band radio call sign KC9QPF, Grabber AT2s on Soft 8s, FIA grill blanket.

Here are some details on our previous comments:

Sulfur does cause a distinct smell in the exhaust, but it is more of a rotton egg smell. The oxidation catalyst on the KJ is comprised of about $100 worth of platinum particles affixed to the cell matrix. Platinum is the best precious metal for reducing HC and CO in a lean burn engine and high quantities of sulfur in the fuel (above 1000 ppm) will degrade the cat performance over time, this is referred to as sulfur poisoning. The aging effect can be reversed by about 80% if the cat is exposed to high flowrates and exhaust temps above 700C for about 10 minutes. The catalyst was necessary on the KJ CRD to meet the emission limits for HC and CO, but it is also true that gas engines make more HC an CO than diesels, but they also use 3-way cats to control the emission output. Diesels do not cycle between rich and lean like a gas engine, except for the newly design VW Jetta that utilizes a lean-nox trap and goes through a rich purge once every 60 seconds or so.

The Bosch CP3 fuel pump on the KJ CRD includes a positive displacement pump on it called a ZP18 lift pump. Most other manufacturers do not use the ZP18 and require an in-tank lift pump. Newer designed Bosch pumps CP3+, CP4 and CP4+ all require an in-tank lift pump. The KJ was designed before these were available on the market. It is not a perfect design and that is why Bosch has since changed their products, it is easier to push instead of pull when it comes to fuel systems. Obviously, there are a lot of bad experiences out there with the stock fuel system. We have just never had a problem with ours other than the limp-home mode caused by very tight tolerances on the fuel pressure regulation control.

Our comment about the EPA and CO2 relates to the emission regulations that were in effect at the time the KJ was sold in the US. It was just recently that final agreement was made to increase the CAFE standards for the auto industry and to create the cap and trade system.

_________________
Providers of wholly developed aftermarket solutions for the KJ CRD.
(248) 977 - 9531

...wow...now everyone just take a deep breath. GDE are our friends. There's no need to be excessively mean to them if you don't happen to agree with what they say. If you consider the context of what they are saying, they haven't said anything wrong and it's not a reason to trash their product. A lot of people seem to like how it's working. Next to Danoid and MrMopar64, these guys are the only ones that can give us insight into the intended design of the CRD...which some of us have had issues with.

A few things for thought just from an education perspective:

--An earlier post above stated that diesel engine do not product appreciable amounts of carbon monoxide. "Appreciable" is a bit of a relative term. When CO enters the human body, it binds to hemoglobin very strongly (understatement) and will occupy the available sites that oxygen would normally bind to in the blood (CO poisoning). A hemoglobin/CO complex will encounter about 10,000 oxygen molecules before being displaced and thus recreating the hemoglobin/oxygen complex. The only remedy for someone with CO poisoning, assuming they're still alive, is to have them breath 100% oxygen for a significant time period. It's in our interest for keep as little CO as possible from coming out of the tailpipe...of any vehicle.

--Mercapton is not a complex. It's simpler than that. It is the analog to an alcohol. The stuff we smell that is added to propane or natural gas is methyl mercaptan or methanthiol or CH3SH (the analog to methanol, CH3OH). If the sulfur is bonded to two carbons, it is then a thioether, and you guessed it, these smell beyond nasty too. Those of us in MI are familiar the plethora of skunks around...that spray is a concoction of thiols, thioethers, thioacids, thioesters, thionoesters, all kinds of other nasty goodies. That home remedy of washing oneself or one's animal with tomato juice actually is done to promote a chemical reaction...oxidation of the thiol and thioethers to their odorless and water soluble sulfoxide and sulfone analogs.

--Sulfur is one of the best ligands in the world for a transition metal (Iron, Platinum, Palladium, Iridium, etc). I use platinum (Pt) all the time as a catalyst for my job. The only thing I want to see around worse than sulfur are amines (carbon-nitrogen compounds). The sulfur will bind to the active sites of the catalyst (like the CO above) and prevent it from doing what you put it in there to do...already correctly stated as "poisoning." The $100 worth of Pt is a fraction of an ounce. It's adsorbed to surfaces outright or as part of high surface area solids materials to allow exposure of the exhaust gasses to as many Pt molecules as possible for efficiency. Oxidative catalyst is just what it implies. Something is taken and reacted in the presence of oxygen to yield an oxidized compound. It just needs sufficient heat to drive the reaction at an appreciable rate. So, CO becomes CO2. Unburned hydrocarbon compounds become CO2. It's all good. If the system was simply a "burner," there wouldn't be a need for a "catalyst"...just add fire for a non-catalytic oxidation/reduction reaction and it's done.

--For reasons I don't quite understand, you can still get 500 ppm "on-road" diesel at the SuperQuik station in Vanceburg, KY. As a matter of fact, you'll be hard pressed to find the 15 ppm stuff anywhere nearby. I wouldn't be surprised if there are other very rural areas that are like this as well.

--The cat might do a little work on the NOx compounds, but that's not what it was designed for, so the benefits if any would be mininscule.

This is a forum for discussion...to learn...trade ideas...

This is not here to attack posters...name call...squash ideas...

Some of ya'll need to take it down a notch and do what we normally do here in the CRD section...Stick Together!

_________________
Founder of L.O.S.T.
2006 CRD Sport
Mods: GDE Hot Tune w/ 364#@2000rpm/Air Box /3" Str8 Exhaust/ASFIR Alum Skids/245-75R-16 Cooper STT PRO/OME LIFT w/Clevis & 4 Spring Isos/AirTabs/Rigid 10" S2 LED/4xGuard Ctr Matrix Bumper
Drag Strip:Reac=.1078_60ft=2.224_1/8=10.39@64.8mph_1/4+16.46@80.8mph

So true. Thanks for the dose of common sense. I apologize to anyone who felt inflamed by my earlier statements. GDE I have settled down and really am glad that you have provided an excellent tune. Everyone certainly should make their own decisions about what they think is best for their own CRD, including whether they remove the cat or install a lift pump for improved driveability.

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Manure green 2005 CRD sport4x4, GDE Hot tune, Cat Gut, OE skids, Draw tight hitch, Duramax lift pump, 160K on multiple varieties of fuel, XM radio, Escort live with Redline, fog light mod, GPS, Icom IC7000 all band radio call sign KC9QPF, Grabber AT2s on Soft 8s, FIA grill blanket.

Anyone who has worked with hydraulic systems knows that it is easier to seal 1000 PSI than to seal a vacuum
By not having an upstream vacuum on the fuel system, you greatly reduce the chances of ingesting air and suffering the consequences.
As all of us know as our CRDs age the chances of having a fuel system vacuum leak increases.
As GMCTD has stated along with others, the fittings between the tank and the steel line going to the filter head are pressure type fittings not vacuum fittings, another good argument for the lift pump.
Conclusion: Omission of the lift pump was a D#mb @$$ BEAN COUNTER MOVE and not a sound Engineering move.
Most Salesmen will say or go along with just about anything to get an order including Bosch Salesmen, that is why Bosch did not stick to what they preach in their Diesel Fuel System Management book.
Unlike Salesmen and others who negotiated away logical decisions, I stick with the Laws of Physics which can not be defied, even by Bean Counters or Salesmen.

As far as fires from fuel leakage around the electrical heater plug, I have had return lines on injectors leak a lot more fuel than mine did when the Dealer cheerfully replaced it under warranty.
When one of our members approached the NTSB about the fire safety issue, they blew him off!
Besides, I would have taken longer to find the leak with out my lift pump.

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2006 Pearl Green CRD
Magnaflow 2 1/2" Cat Back
KJ Extra Leg Room Brackets, Carter Lift Pump, V6 Airbox, ORM
Fuel cooler, Oil Separator, Progard 7
Gauges EGT Boost Trans Temp Oil Pres, Michelin LXT AT2 245 70 R16
7,000# Draw Tight hitch, PML EX Deep Trans Pan
Centrifuge, SunCoast, Transgo, RAM TCM, InMotion Stage 2
Wife's 99 TDI VW Beetle

Speaking about fuel leak fires... I had a "small" fuel leak on my VW Jetta TDI at a time when I had to get to the Eastern end of Kentucky from Florida in 2 days, over a weekend. I drove 800 miles with this "small" fuel leak... From the #2 cylinder HIGH PRESSURE LINE that had completely separated at the injection pump outlet. I drove 800 miles with the pump SHOWERING the engine with diesel fuel. When I got there, I opened the hood and collected over a gallon of fuel as it dripped from the under-hood engine blanket.

If that was gasoline, the car would have burned in Orlando where the leak started when the line blew while I was driving.

Granted, the mileage wasn't that great, but the car ran just fine (actually the power wasn't too bad either) and was good as new (and shiny clean!) once I replaced that line. Gotta love diesel fuel. Safe and powerful.

OHHH... A whole bunch of sacred cows are on the way to the slaughter house!!!! Greendiesel you just cost yourself a crap load of money. How dare you say the KJ doesn't need a lift pump to run right? Don't you know it is written in the Bosch diesel bible??? I suggest you take it back now and never bring up the word "lift pump" again. Trust me on this one.....
In case your wondering ,I also believe no lift pump is needed, just fix the leaks.

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2005 sport crd-SOLD No regrets