Fuel heater? What fuel heater?

gmctd · **Posted:** Sun Nov 23, 2014 11:17 pm

A dissertation on the KJ fuel manager, a filter head with electric heater and inlet fuel temperature sensor

View of removable heater puck is from the filter side, orienting the Fuel Heater to the driver-side of the vehicle

The heatable head accepts a screw-on fuel filter with integral water-in-fuel sensor and drain. The area above the filter contains a 12v electric
heater which is normally submerged in fuel - the heater is comprised of seven (7) positive-coefficient resistive disk elements held in place between two
aluminum plates which transfer heat into the surrounding fuel - the heater recieves power from the IGN switch at key-on, and the resistive
heater elements activate at ~40*F, warming the resident fuel in the filter - rising temperature increases element resistance, slowly turning them off as fuel temperature rises to acceptable operating values

Catastrophic failure in the heating element occurs when air has leaked into the fuel line back at the tank and is drawn into the fuel head with
the fuel - fuel, denser than air, settles to the bottom of the filter - air, being lighter than fuel, accumulates in the area above the
filter where the heater is located - the heater requires fuel density to control rate of heat rise - repeated rapid rise in air alone eventually
burns the hermetic seal in the connector, damaging the harness plug, with resultant fuel leak-thru

This illustrates catastrophic failure of the heating element connector - upper terminal conducts heater current to the aluminum plate beneath the disks - lower terminal connection to upper plate has
been burned-thru - the seven dots in the circle are electrical terminals for the heater-discs - unseen beneath the plate are the opposite
electrical terminals on the lower plate - the lower terminal would conduct heater current thru the aluminum plate to the upper disk terminals, butcept it's burned open
- luckily, in this case, without any resultant fire

The Fuel Temperature Sensor is located in the bottom connector - as can be seen, it is isolated from the fuel above the filter cannister, and does not
function to measure fuel heated by the Fuel Heater element - it resides in the chamber above which connects directly to the port for incoming
fuel from the fuel tank - thus it senses temperature of pre-filtered fuel which has not passed into the fuel filter and been further heated by engine bay heat

The ECM uses the FTS to determine whether incoming fuel is too hot to be useable - the cooler fuel flowing from the tank is used to cool the CP3,
keeping it within spec'ed limits to prevent galling the 30,000psi hi-pressure plungers, causing the CP3 to sieze-up

ECM senses high temp fuel from the tank, commands the Fuel Quantity Solenoid on the CP3 to limit fuel to the hi-pressure gallery, being input from the low-pressure gallery - the
Cascade Overflow Valve in the low-pressure gallery then bypasses all excess fuel, which is much cooler than that fuel returned from the rail and injectors, back to the
fuel tank - constant volume of air-flow beneath the vehicle and across the fuel tank then brings tanked fuel down to acceptible operational
temperatures - ECM commands FQS to allow more volume for the rail, rail excess dumps back to the tank, and it's deja vu all over again*

The fuel heater can be disabled with little detrimental effect - the Fuel Temperature Sensor must be connected at all times to prevent
catastrophic damage to the CP3 - fuel thermal expansion of 'only a couple percent' can severely damage an injection pump with
only a couple micro-percent allowable variation in spec'ed plunger\barrel clearances

*Likely, this is prime reason why GM Duramax Diesel vehicles are factory-equipped with return-fuel cooler systems - BOSCH officially notes that
some CP3 fuel supply systems should be equipped with a return-fuel cooler system

I presumed this could be specifically aimed at the short-wheelbase KJ with short return-fuel line preventing sufficient thermal conduction into ambient air-over flow

flash7210 · **Posted:** Sun Nov 23, 2014 11:44 pm

http://pages.ebay.com/link/?nav=item.view&alt=web&id=111459106137

Speaking of fuel cooler, I added one of these.
It's small but easy to install in the grill.

ArmyChief · **Posted:** Mon Nov 24, 2014 10:58 am

Did you measure high fuel temps? Is that why you installed a fuel cooler?
Where did you tap into the fuel system...any pics?

Thanks

flash7210 · **Posted:** Mon Nov 24, 2014 11:40 am

No, didn't measure any fuel temps.
Probably should have.
I just went on the feeling of sluggish performance durning peak summer heat and when fuel level gets below 1/2 tank.

ArmyChief · **Posted:** Mon Nov 24, 2014 11:54 am

Oh have pics, any adapters used

ArmyChief · **Posted:** Mon Nov 24, 2014 12:22 pm

gmctd,

Does Bosch publish a know safe fuel temp spec?

I know on a Cummins, under a normal operating environment, the CP3 pump send excessive fuel back to the tank..this keeps the pump cool. When the lift pump fails, fuel volume can drop to the point where near zero fuel is sent back to the tank, causing the CP3 pump to overheat.

Two things:

Installing a lift/pusher pump on a CRD, may be more than enough to keep the CRD CP3 pump cool (I have to image our CP3 pump is the same as used on a Cummins...so there would be excessive fuel returned to the tank..hence cooling the CP3 pump.

Whats your thoughts (trying to strike up good, technical conversation)

gmctd · **Posted:** Mon Nov 24, 2014 2:16 pm

I 'spect they do, but I don't have the figures - back in ought 7-8, when I posted the CP3 operational description, there was absolutely no definitive data on the CP3, not even in the Dodge\KJ\GM\FMC service manuals, in which limited descriptions contained many errors and omissions - I spent several months hitting every reference to CP3 that I could find on the 'net and in book stores to get the meager data that I corrected and posted - very slim pickings at the time

I posted that data on each venue with specific numbers relevent to the oem's application - this is the KJ version:

viewtopic.php?f=5&t=25047&hilit=bosch+cp3

You will find similar on the DODGE Cummins and GM DURAMAX forums, specifically edited for their application

All CP3 versions utilize the FQS and COV to regulate fuel volume thru the rail, and fuel volume bypassed to maintain minimal tanked fuel temperature - FQS in all cases always commanded by the ECM - this was the spec'ed requirement noone chose to ignore - GM chose to install return-fuel cooler because the V8 DMAX is available in the Suburban - DODGE offers no such option in the DCJ sport-utes, likely also assuming that long return-fuel line and equally long fuel-supply line in the long-wheelbase trucks could be sufficient additional fuel-cooling for the big 6-cyl, having less return-fuel volume than the big V8

An extermal lift-pump solves the problem of leaky fuel lines - it does nothing for cooling because fuel flow thru the CP3 is controlled by the mechanical COV, which is after the internal, very powerful gear-type lift pump, which can pull ~20"HG on the fuel tank - KJ CP3 regulated housing pressure is 78psi - Cummins and Dmax regulated housing pressure is 180psi - external lift-pump (recommended pressure less than 15psi) has no effect on any CP3 internal fuel flow or return volume

NOTE: the fuel cooler must be installed in the return-fuel line - cooler-radiator exposure to winter temps could cause shut-down if installed in the fuel supply line

Further:
My big 3500 Cummins Ram dooley returns ~24-26mpg at 50mph
If I drive 50mph for one hour, fuel consumed at 25mpg in 50 miles is 2gal
Fuel consumed per hour is therefore 2gph - 10mpg would be only 5gph
What is the thinking behind the universal Dodge forum claims that my truck needs a $700 200gph fuel lift pump system, or it will never ever run right again?
200gph at 50mph = insanity
$700 = dementia

To wit: a 15psi 15-35gph lift pump is more than suitable for my big Cummins, and for the smaller KJ, 2.8L being half the 5.9L displacement of the Cummins

Bigger is ain't always better

Word up, dudes................

WWDiesel · **Posted:** Mon Nov 24, 2014 4:00 pm

gmctd wrote:

An extermal lift-pump solves the problem of leaky fuel lines - it does nothing for cooling because fuel flow thru the CP3 is controlled by the mechanical COV, which is after the internal, very powerful gear-type lift pump, which can pull ~20"HG on the fuel tank - KJ CP3 regulated housing pressure is 78psi - Cummins and Dmax regulated housing pressure is 180psi - external lift-pump (recommended pressure less than 15psi) has no effect on any CP3 internal fuel flow or return volume

NOTE: the fuel cooler must be installed in the return-fuel line - cooler-radiator exposure to winter temps could cause shut-down if installed in the fuel supply line

To wit: a 15psi 15-35gph lift pump is more than suitable for my big Cummins, and for the smaller KJ, 2.8L being half the 5.9L displacement of the Cummins

Bigger ain't always better

Word up, dudes................

Bottom line then, can you make a recommendation!! Do we all need to consider adding an inline fuel cooler on the return line if we have added the in-tank lift pump conversion. Ah, but you stated; that it returns the same regardless if it has a lift pump or still the OEM configuration. So with that being said; all CRD systems should have a cooler in the return line just to be on the safe side. gmtd, does this apply to the Dodge as well? Same pump return volume I presume? I do plan to add the in-tank lift pump to it as well at some point, it still has the OEM motor mounted lift pump at present.
Good subject for discussion and consideration!
Ball is in your court! :wink:

papaindigo · **Posted:** Mon Nov 24, 2014 4:38 pm

Way back in 09 GDE said a fuel cooler was not needed. See http://www.greendieselengineering.com/j ... st/23.page

ArmyChief · **Posted:** Mon Nov 24, 2014 4:46 pm

gmctd wrote:

All CP3 versions utilize the FQS and COV to regulate fuel volume thru the rail, and fuel volume bypassed to maintain minimal tanked fuel temperature - FQS in all cases always commanded by the ECM - this was the spec'ed requirement noone chose to ignore - GM chose to install return-fuel cooler because the V8 DMAX is available in the Suburban - DODGE offers no such option in the DCJ sport-utes, likely also assuming that long return-fuel line and equally long fuel-supply line in the long-wheelbase trucks could be sufficient additional fuel-cooling for the big 6-cyl, having less return-fuel volume than the big V8

An extermal lift-pump solves the problem of leaky fuel lines - it does nothing for cooling because fuel flow thru the CP3 is controlled by the mechanical COV, which is after the internal, very powerful gear-type lift pump, which can pull ~20"HG on the fuel tank - KJ CP3 regulated housing pressure is 78psi - Cummins and Dmax regulated housing pressure is 180psi - external lift-pump (recommended pressure less than 15psi) has no effect on any CP3 internal fuel flow or return volume....

Gmtcd,

I hope you don't mind a technical conversation, where all parties disagree with one thing or another. I am fairly new to the forum, but been in the trade professionally for over 20 years.
Now, the way it was explained to me by a cummins instructor was that CP3 pump failures are directly related to failed lift pumps on Dodge Ram trucks. Pressure switches are actually installed on Cummins vehicles and the Cummins ECU has a pin for it. Dodge opted to go utilize it. I understand the CP3 pump can suck a golfball through a garden hose. However, logic would dictate if a small positive pressure were at the inlet, it would reduce stress on pump. You state a lift pump is only for fuel leaks, but they are standard on Dodge Ram Cunmins.

Maybe Dodge doesn't use a external cooler cause THEY utilize a lift pump. Whereas, GM Duramax decided not to utilize a lift pump, hence the reason they have an external cooler. Trust me, Duramaxs biggest issue is the filter housing too, just like the CRD. leaks, no starts.

Lastly, I'm in SW Florida.. HOT, plus I'll be towing a 6600 lbs Catamaran boat. I'll take a look at the fuel temp data PID while driving to see what kind of temps I get. I'll also ask some other instructors in the know about typical and max fuel temps. For those without a capable scantool to log fuel temp PID...a DVOM with the voltage to temp specs should work.

WWDiesel · **Posted:** Mon Nov 24, 2014 5:09 pm

I was told years ago by a good friend who was a mechanic at the Dodge dealership that the reason the injection pumps were failing was due to fuel starvation when the OEM lift pump did not supply enough fuel to keep the injection pump lubricated. Diesel fuel is the only thing that lubricates it!
This is when I added a fuel pressure gauge that I could monitor at all times on the pump side of the filter housing and started adding a quart of 2 cycle oil in the fuel at every fill up....
I also had the OEM lift pump replaced under warranty before it ran out due to I had noticed a drop in fuel pressure when engine was under load even with a new fuel filter installed.
What I am having trouble wrapping my brain around is how could the motor keep running if fuel volume got low enough to fail to lubricate the injection pump but allowed the engine to run to the pump failed...
What is your thoughts.... :dizzy:

Another comment, we going to heat the fuel coming in and cool it with an in line cooler before putting it back in the tank???
I presume this would only be a summer time issue, high ambient temperature concern when say temperatures are above say 90 degrees or so??? It get up above 100 here in the hot summer time!!!

gmctd · **Posted:** Mon Nov 24, 2014 6:08 pm

Good questions and input, all -

Chief, aymk, we are primarily discussing the JEEP KJ CRD 2.8L Diesel on this forum - this KJ has demonstrated countless fuel delivery problems, all traceable to the use of a vacuum-based draw-type system utilizing pressure-type fuel lines - air leaks into the connections but much denser Diesel fuel does not leak out, resulting in no wet spot to indicate leakage -
dealer cannot see\find a leak, throws up his hands and advises you that he has a good-running V6 KJ that you might be interestd in

And, as demonstrated, the fuel heater failures are directly traceable to leaked air in the system

So, a good solution, since the KJ was not factory-euipped with a BOSCH-recommended external lift-pump, is to install a lift-pump, converting the fuel-supply system to the pressurized push-type system compatible with the fuel line connections

All things considered, then, my statement that a fuel lift-pump solves the problem of fuel line leakage is correct - also my recommendation to install the Cummins in-tank fuel lift-pump
viewtopic.php?f=5&t=26385&hilit=It%27s+10pm

The GM Dmax V8 was also not factory-equipped with an auxiliary lift-pump, and many after-market solutions have been created and posted on those forums - some have been installed here

WW, The dealer is confusing the many BOSCH VP-44 IP failures with the few CP3 failures caused by non-approved lift-pump substitution, using lift-pumps that blocked fuel flow-thru after failure - like the $700 200gph abortion referred to , earlier
- all Cummins lift-pumps are flow-thru-when-failed types, which allow the powerful gear-type lift-pump in the CP3 to draw fuel thru the failed pump
- multiple-banked fuel filters added due to misconception also result in failures of this type, by restricting fuel flow
- nothing can be designed\created\rendered as idiot-pruf - scan thru any of the Cummins forums to get a better sense of that

BOSCH reported that the millions of warranty-returned VP44 IPs, most were not mechanical pump failures, but FSD fuel solenoid driver module failure due to overheating resulted from insufficient fuel-flow after the lift-pump began failing -
each and every carton of CARTER lift-pump contains instructions stating the pump, designed for pusher-type use, is not suitable for draw-type service, and should be mounted at or near the fuel tank - Dodge engineers chose to ignore this, instead mounting the CARTER pusher pump directly on the engine block - guess why DODGE had millions of lift-pump failures over the years, with resulting VP-44 electrical failures?

Also, in the interim years, DODGE upgraded the fuel manager to a new type with the lift-pump directly-attached to the cannister housing -

- did that help? Guess...................

It was only in 2004 that DCJ began installing the in-tank system for the CRD, 2-years after inroducing the CRD engine in 2002, further offering kits to upgrade any of the preceeding model-year trucks back thru 1994 to in-tank systems - hmmmm.....wonder why...........

I would recommend that KJ's in temperate climates be equipped with a return-fuel cooler, particularly if regularly used for towing\hauling , and any used for slow off-roading where there is little air flow-thru - temperature-controlled fan-over types are available for automatic transmission use, and are suitable for fuel service

gmctd · **Posted:** Mon Nov 24, 2014 7:19 pm

ArmyChief wrote:

[Gmtcd,

I hope you don't mind a technical conversation, where all parties disagree with one thing or another. I am fairly new to the forum, but been in the trade professionally for over 20 years. Your input is appreciated, Chief - hopefully I can offer some factual input to solve any apparent difference of opinion
Now, the way it was explained to me by a cummins instructor was that CP3 pump failures are directly related to failed lift pumps on Dodge Ram trucks. True, some due to LP mounting location and some due to unsuitable substitution Pressure switches are actually installed on Cummins vehicles and the Cummins ECU has a pin for it. Dodge opted to go utilize it. I understand the CP3 pump can suck a golfball through a garden hose. However, logic would dictate if a small positive pressure were at the inlet, it would reduce stress on pump. True - BOSCH recommends LP useage You state a lift pump is only for fuel leaks, but they are standard on Dodge Ram Cunmins.Both true, but my statement references problems with our KJs - mine has been gifted with a Cummins in-tank lift pump

Maybe Dodge doesn't use a external cooler cause THEY utilize a lift pump. Not exactly true - the long-wheelbase of the Ram and fewer cylinders than the V8 are why DCJ did not use the cooler Whereas, GM Duramax decided not to utilize a lift pump, hence the reason they have an external cooler. Also not exactly true - the 5.9L has six injectors returning hot fuel to the tank - the Dmax has eight injectors returning hot fuel to the tank - GM also believed BOSCH specs for the internal lift pump - unfortuntely, Bosch didn't spec maximum distance between tank and CP3 - Jeep also followed that spec in the much shorter wheel-base KJ, with the resultant fuel system failures enjoyed by one and all - BOSCH did state that some CP3 systems would require an external lift pump - I think KJ'ers have proven that to be correct Trust me, Duramaxs biggest issue is the filter housing too, just like the CRD. leaks, no starts. True, and I also have been aware of that - many owners have installed after-market lift pumps, as have KJ'ers

Lastly, I'm in SW Florida.. HOT, plus I'll be towing a 6600 lbs Catamaran boat. I'll take a look at the fuel temp data PID while driving to see what kind of temps I get. I'll also ask some other instructors in the know about typical and max fuel temps. For those without a capable scantool to log fuel temp PID...a DVOM with the voltage to temp specs should work.

gmctd · **Posted:** Mon Nov 24, 2014 7:33 pm

WWDiesel wrote:

I was told years ago by a good friend who was a mechanic at the Dodge dealership that the reason the BOSCH VP-44injection pumps were failing was due to fuel starvation when the failing\failed OEM engine-mountedlift pump did not supply enough fuel to keep the injection pump lubricated. Diesel fuel is the only thing that lubricates it! Same with the CP3- the mechanical P7800-series IP's were lubricated by pressurized engine oil
This is when I added a fuel pressure gauge that I could monitor at all times on the pump side of the filter housing and started adding a quart of 2 cycle oil in the fuel at every fill up....Good - this is required for the mechanical pumps because of the low-sulphur fuel with reduced lubricity
I also had the OEM lift pump replaced under warranty before it ran out due to I had noticed a drop in fuel pressure when engine was under load even with a new fuel filter installed.Also good, but you should seriously consider mounting it near the fuel tank, far back as you can safely mount it - it is a pusher-type pump, intended to pressurize the fuel supply system from the tank forward - the design severely-limits any draw-from-the-tank capability - 'nuther words, in shade-tree-ese, it don't suck too good - which is why the VP-44 eventually fails - again, BOSCH's official report to DODGE on the unusually-high failure rate of the VP-44 was electronic module failure resulted from insufficient fuel volume - the pump itself seldom showed any mechanical failure
What I am having trouble wrapping my brain around is how could the motor keep running if fuel volume got low enough to fail to lubricate the injection pump but allowed the engine to run to the pump failed...Reduced LP output could supply enuff to run the engine, but not enuff to cool the internal electronic module, which required constant hi-volume fuel-over to keep it cool - all volume in excess of that required to run the engine was constantly bypassed back to the tank, ensuring thermal stability of the electronic driver module
What is your thoughts.... :dizzy:

I likes gurls............. :BANANA:

Another comment, we going to heat the fuel coming in and cool it with an in line cooler before putting it back in the tank???Heating the filtered fuel in the filter is a winter-time requirement to keep the fuel from freezing - cooling the engine-heated return-fuel is required when towing\hauling, or off-road use when not acting like an idiot - hmmm...well, maybe even moreso when acting like an idiot
I presume this would only be a summer time issue, high ambient temperature concern when say temperatures are above say 90 degrees or so??? It get up above 100 here in the hot summer time!!!I would specifically recommend a cooler for severe use in those temperatures

thermorex · **Posted:** Mon Nov 24, 2014 7:42 pm

What do you guys think about a Derale heat sink cooler? Something similar to this:

http://m.summitracing.com/parts/der-13250

gmctd · **Posted:** Mon Nov 24, 2014 7:50 pm

WWDiesel wrote:

[Bottom line then, can you make a recommendation!! Do we all need to consider adding an inline fuel cooler on the return line if we have added the in-tank lift pump conversion. Ah, but you stated; that it returns the same regardless if it has a lift pump or still the OEM configuration. So with that being said; all CRD systems should have a cooler in the return line just to be on the safe side. I believe this to be true - never know how the truck will be used in the future gmtd, does this apply to the Dodge as well? Your VP-44 5.9L requires no fuel return cooler- if you want one, do it to it Same pump return volume I presume? I do plan to add the in-tank lift pump to it as well at some point, it still has the OEM motor mounted lift pump at present.Ok, this is where you should concentrate your endeavors - the CARTER LP is a pusher-type pump, designed to pressure-up the fuel supply system up to and thru the fuel filter - current location near the filter makes it a draw-from-tank, or vacuum-type, system - this configuration has resulted in nearly all Dodge's VP-44 and some CP3 IP failures up thru 2005
Good subject for discussion and consideration!
Ball is in your court! :wink:

gmctd · **Posted:** Mon Nov 24, 2014 8:23 pm

FYI - I rebuilt\refurbished a severely rode-hard-and-put-up-wet white '96 2wd x-cab 5-spd dooley - once completed, I began looking for a complete white duplicate with good cab\bed, bad engine, to no avail

A 2001 white jewel showed up on CRAIG'SLIST, actually pre-owned by a little ole lady, recently expired due to emphesema - white, xcab 4-dr, auto, new Michelins, full towing package, 24v, a real find -

I noticed each time I went to drool over it the salesman had it running when I arrived - my suspicions immediately peaked, being aware of various VP-44 symptoms while dying - purchased it running, drove to the house, parked it overnite

Brite'n'early next a.m., I placed the key in the IGN, hit START, only to find excellent cranking but no running - shutting it down while fearing the worst, I kludged-up a fuel pressure test set, on with the key, LP was running strong, but no fuel pressure - anywhere

Fearing even more worst, I shut it down, went in the house to get on eBay, ordered a new CARTER Cummins LP and rebuilt VP-44 to get stuff on the way -

Going back out, I then proceeded to pull the CARTER lift pump off the engine for disassembly, which is my wont

The CARTER LP has a simple internal fuel regulator\bypass system, whereby a SS ball is held onto a seat by a spring, tensioned for pressure as required by type of service - when spec'ed pressure is reached, excess fuel flows back into the input, recirculating until demand for additional volume increases - works fine, lasts a long time.............

Opened the pump to find the ball had passed thru the end of the spring and was captive inside the spring coils, such that the pump was still functional, supplying volume to the IP at much less than designed pressure

VOILA!!!!!!!! Maybe the VP-44 had survived, and all that was needed was to replace the LP - which turned out to be the case - had to rebuild the starter, tho, which I would have, anyway

And, the new lift pump resides in it's natural location, back on the inside framerail near the fuel tank, secured in the stainless steel fuel pipe with stainless steel compression-type fittings - no leak there and 14psi at the VP-44 input banjo, constantly monitored and displayed on the EDGE JUICE module - no pressure-drop across the factory fuel filter, even in the ~600hp tuning mode - the oem CARTER lift pump is absolutely adequate for a street truck - unless I foolishly begin believing the Cummins forums hype that my truck will never again run right without the $700 200gph aftermarket unit, originally designed for 15-liter 18-wheeler systems - or, maybe the 400gph unit is even more suitable, according to some.............

However, in all my 60-some-odd years makanikin', I never saw this type of failure - I removed the ball, reduced the end-diameter of the spring by squeezing with suitable pliers, re-assembled the pump, which now resides in my truck box for future situations

And there you have my sad story with Cummins Lift Pump failure - enjoy..............

ArmyChief · **Posted:** Mon Nov 24, 2014 8:27 pm

gmctd wrote:

ArmyChief wrote:

[Gmtcd,

I hope you don't mind a technical conversation, where all parties disagree with one thing or another. I am fairly new to the forum, but been in the trade professionally for over 20 years. Your input is appreciated, Chief - hopefully I can offer some factual input to solve any apparent difference of opinion
Now, the way it was explained to me by a cummins instructor was that CP3 pump failures are directly related to failed lift pumps on Dodge Ram trucks. True, some due to LP mounting location and some due to unsuitable substitution Pressure switches are actually installed on Cummins vehicles and the Cummins ECU has a pin for it. Dodge opted to go utilize it. I understand the CP3 pump can suck a golfball through a garden hose. However, logic would dictate if a small positive pressure were at the inlet, it would reduce stress on pump. True - BOSCH recommends LP useage You state a lift pump is only for fuel leaks, but they are standard on Dodge Ram Cunmins.Both true, but my statement references problems with our KJs - mine has been gifted with a Cummins in-tank lift pump

Maybe Dodge doesn't use a external cooler cause THEY utilize a lift pump. Not exactly true - the long-wheelbase of the Ram and fewer cylinders than the V8 are why DCJ did not use the cooler Whereas, GM Duramax decided not to utilize a lift pump, hence the reason they have an external cooler. Also not exactly true - the 5.9L has six injectors returning hot fuel to the tank - the Dmax has eight injectors returning hot fuel to the tank Trust me, Duramaxs biggest issue is the filter housing too, just like the CRD. leaks, no starts. True, and I also have been aware of that

Lastly, I'm in SW Florida.. HOT, plus I'll be towing a 6600 lbs Catamaran boat. I'll take a look at the fuel temp data PID while driving to see what kind of temps I get. I'll also ask some other instructors in the know about typical and max fuel temps. For those without a capable scantool to log fuel temp PID...a DVOM with the voltage to temp specs should work.

Make sense also..thanks

gmctd · **Posted:** Mon Nov 24, 2014 9:20 pm

thermorex wrote:

What do you guys think about a Derale heat sink cooler? Something similar to this:

http://m.summitracing.com/parts/der-13250

That's the brand I couldn't remember - I have one, but maybe it's smaller, from about 20yrs ago - I prefer it to the un-blown type, because it functions in stop'n'stop traffic situations

ATXKJ · **Posted:** Mon Nov 24, 2014 9:37 pm

papaindigo wrote:

Way back in 09 GDE said a fuel cooler was not needed. See http://www.greendieselengineering.com/j ... st/23.page

that didn't stop folks from installing coolers before 09 - never heard of any problems with them.

Fuel heater? What fuel heater?

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