Fuel Temperature

3camp · **Posted:** Sun Jul 27, 2008 1:22 pm

Hi been lurking awhile till I found a CRD. I read that when the fuel gets to hot the PCM will limit the power. Does anyone know at what temperature it starts at and what is too hot?

Joe Romas · **Posted:** Sun Jul 27, 2008 3:30 pm

This dosen't answere your question but I've noticed after filling up in hot weather the jeep has more gusto with cool fuel from out of the underground fuel storage tank :lol:

This leads me to believe it's a sliding scale type of thing.

tjkj2002 · **Posted:** Sun Jul 27, 2008 3:56 pm

Time for a cool can,a little etheylene glycol and dry ice will last a long time,and they work for adding more HP and torque.

http://www.jegs.com/p/Moroso/747208/10002/-1/10291

gmctd · **Posted:** Sun Jul 27, 2008 4:34 pm

That works for gasoline, not for Diesel fuel - a simple inline cooler to bring fuel temps down to ambient B4 dumping back into the tank is sufficient - a DeRaille fan-over\similar in the fuel return line between fuel rail and tank will keep tank temps well below critical 168degF - try it, you'll like it.....................................

tjkj2002 · **Posted:** Sun Jul 27, 2008 4:50 pm

gmctd wrote:

That works for gasoline, not for Diesel fuel - a simple inline cooler to bring fuel temps down to ambient B4 dumping back into the tank is sufficient - a DeRaille fan-over\similar in the fuel return line between fuel rail and tank will keep tank temps well below critical 168degF - try it, you'll like it.....................................

Cool cans work for gas or diesel,both style engine respond to cooler fuel.The cool can will bring the fuel temps down near 32 degrees where the finned inline cooler may only bring it down to 100-120 degrees if your lucky.

Fuel,be it gas or diesel,is more dense the colder it is,just like cooler air helps make more power in your turbo diesels.

gmctd · **Posted:** Sun Jul 27, 2008 5:09 pm

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

tjkj2002 · **Posted:** Sun Jul 27, 2008 5:16 pm

gmctd wrote:

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

That may hold tru for your glowplug infested engines but TRUE turbo diesels(no glow plugs) respond to cooler fuel and air,your CRD's and any diesel offered in a 1ton and below vehicle is computer infested so it will not run right with cold fuel and air due to emissions.Just like water/meth injection helps build more power by cooling the intake charge which helps cool the EGT's.

curtis · **Posted:** Sun Jul 27, 2008 6:12 pm

gmctd wrote:

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

2X that, Ice cold diesel fuel is as bad as hot diesel fuel.

Stick to gas dude :lol:

curtis · **Posted:** Sun Jul 27, 2008 6:18 pm

tjkj2002 wrote:

gmctd wrote:

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

That may hold tru for your glowplug infested engines but TRUE turbo diesels(no glow plugs) respond to cooler fuel and air,your CRD's and any diesel offered in a 1ton and below vehicle is computer infested so it will not run right with cold fuel and air due to emissions.Just like water/meth injection helps build more power by cooling the intake charge which helps cool the EGT's.

Oh yeh I forgot, Water injection is for cooling the pistons and the the exhaust half of the turbo. If your running enough boost and fuel the cylinder temps can get high enough to melt holes through the pistons, and burn up the turbo. Has nothing to due with the intake being denser. Most high performance diesels can run upwards of 100 psi of boost so air density isn't an issue.

Stick to gas..

tjkj2002 · **Posted:** Sun Jul 27, 2008 6:24 pm

curtis wrote:

gmctd wrote:

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

2X that, Ice cold diesel fuel is as bad as hot diesel fuel.

Stick to gas dude :lol:

Why your CRD is just a over-glorified gas engine,bet you didn't know that,all light/medium duty so called diesels are just a gas hybrid engine.Like I said TRUE diesels do not need glowplugs,they use 100% cylinder heat to combust fuel/air mix,even at startup.You can thank GM.

Oh and "ice" cold diesel is alot colder then 32 degrees,about 15 degrees is the standard gel point in most diesel fuels.

curtis · **Posted:** Sun Jul 27, 2008 6:28 pm

tjkj2002 wrote:

curtis wrote:

gmctd wrote:

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

2X that, Ice cold diesel fuel is as bad as hot diesel fuel.

Stick to gas dude :lol:

Why your CRD is just a over-glorified gas engine,bet you didn't know that,all light/medium duty so called diesels are just a gas hybrid engine.Like I said TRUE diesels do not need glowplugs,they use 100% cylinder heat to combust fuel/air mix,even at startup.You can thank GM.

Oh and "ice" cold diesel is alot colder then 32 degrees,about 15 degrees is the standard gel point in most diesel fuels.

Glow plugs are only used to start the engine. All my diesel buddies with there big Dodge and Ford trucks must have "hybrid" engines also because they ALL have glow plugs to start the engines... Nuf said.

tjkj2002 · **Posted:** Sun Jul 27, 2008 6:47 pm

curtis wrote:

tjkj2002 wrote:

curtis wrote:

gmctd wrote:

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

2X that, Ice cold diesel fuel is as bad as hot diesel fuel.

Stick to gas dude :lol:

Why your CRD is just a over-glorified gas engine,bet you didn't know that,all light/medium duty so called diesels are just a gas hybrid engine.Like I said TRUE diesels do not need glowplugs,they use 100% cylinder heat to combust fuel/air mix,even at startup.You can thank GM.

Oh and "ice" cold diesel is alot colder then 32 degrees,about 15 degrees is the standard gel point in most diesel fuels.

Glow plugs are only used to start the engine. All my diesel buddies with there big Dodge and Ford trucks must have "hybrid" engines also because they ALL have glow plugs to start the engines... Nuf said.

They sure do,I've worked on many diesels that do not need,nor have any,glowplugs and they start just fine,even at -30 degrees(gotta love Fiarbanks Alsaka in January,BBBRRRRRRR).Also they do produce more torque with cold fuel and air on the engine dyno,I now since I dynoed a few myself,no electronics either,and no emisions to worry about.

3camp · **Posted:** Sun Jul 27, 2008 6:53 pm

The reason I wanted to know the high temperature I live in MA to cold in the winter for biodiesel but if I warmed the tank up with engine coolant above 50 degrees would be fine. If the fuel in the tank gets up to coolant temperature is that to hot on a long drive.

05infernoCRDL · **Posted:** Sun Jul 27, 2008 7:23 pm

tjkj2002 wrote:

curtis wrote:

tjkj2002 wrote:

curtis wrote:

gmctd wrote:

Not even true for Diesel fuel - fuel temp in the pump is best at ~125degF - might wanna do some reading\research\fact finding B4 passing off gasser(patooie!) tech(?) as Diesel compatible - that's the sorta myth\superstition stuff that breaks Diesel engines - even best intake air temp for best economy is ~150degF, so no super-chilled air into the inlet, either - remember, or FYI: gassers (patooie!) are spark-infested engines - Diesels are heat-combustion engines - too cool is just as inefficient as too hot, because the fuel is not trucked in with the intake air charge, and the stoke is not dependent on temperature\density - no icy cool cans for Diesel engines

2X that, Ice cold diesel fuel is as bad as hot diesel fuel.

Stick to gas dude :lol:

Why your CRD is just a over-glorified gas engine,bet you didn't know that,all light/medium duty so called diesels are just a gas hybrid engine.Like I said TRUE diesels do not need glowplugs,they use 100% cylinder heat to combust fuel/air mix,even at startup.You can thank GM.

Oh and "ice" cold diesel is alot colder then 32 degrees,about 15 degrees is the standard gel point in most diesel fuels.

Glow plugs are only used to start the engine. All my diesel buddies with there big Dodge and Ford trucks must have "hybrid" engines also because they ALL have glow plugs to start the engines... Nuf said.

They sure do,I've worked on many diesels that do not need,nor have any,glowplugs and they start just fine,even at -30 degrees(gotta love Fiarbanks Alsaka in January,BBBRRRRRRR).Also they do produce more torque with cold fuel and air on the engine dyno,I now since I dynoed a few myself,no electronics either,and no emisions to worry about.

my CRD has started just fine at 7* no glow plugs... was a bit noiser for a few min but no a problem starting... and the "true" diesels you are talking about take several rotations to get started not 1 like our engines... any diesel in decent shape will start with no glow plugs if they have two battery (or a 24V) system(s) and a starter to take the abuse. the GP's only let the engine start with fewer cranks and less noise

as for the temp of the fuel in the winter i would not want it at engine op temp... 50* should be fine... the problem you are going to have is when it has sat over night or through the day, that inital cold start

warp2diesel · **Posted:** Sun Jul 27, 2008 8:08 pm

Please don't confuse an Indirect Injection Diesel engine like the old automotive engines of the past that needed glow plugs to start at 60f with 21 to 1 compression ratios. On problem with these old IDI engines is that they sent a lot of the fuel energy into the cooling system due to the pre combustion chambers in the cylinder head. Emissions, two stage injectors like the early TDI and common rail put these old horses out to pasture.
Our CRDs use the glow plugs to speed up starting and reduce emissions as do the VW TDI engines. With the glow plugs and a very low battery instead of having to twirl the engine over to produce enough heat to start, our CRDs just need to turn fast enough for the CP3 to get enough pressure up to vaporize the fuel and the engine will start. I found this out when a portable refer ran my battery dead and I used my tractor to give it a jump.
In addition to the mega electric starters and massive batteries (like my old Perkins), I have seen diesel engines with "thermostarts", a diesel fuel blow torch in the intake, pony engines, LP gas torches in the intake, OLD IH engines that start on gas and switch to diesel, Burning wicks that screw into the head, either assist, and even detonators that act like a rifle cartridge with out a bullet. Glow plugs are a cost effective way to assist in starting and reduce emissions. Most modern diesel are using them with few hold outs.

Compression ignition = Diesel :!:

Gassers are Spark ignition.

tjkj2002 · **Posted:** Sun Jul 27, 2008 8:21 pm

Quote:

Compression ignition = Diesel

Gassers are Spark ignition.

Not a 100% true,I run a engine that uses no spark plugs,but has a glow plug and uses compression ignition after start-up,but does not use diesel.Actually I have 3 vehicles like that,one has uses engines that make more HP and torque per cubic inch then even a top fuel dragster.

warp2diesel · **Posted:** Sun Jul 27, 2008 8:31 pm

When you can climb a hill, tow a trailer, run the AC and comply with emissions with your two cycle model airplane engine, let us all know. Have fun flying

Is the fuel cheaper than printer ink :?:

tjkj2002 · **Posted:** Sun Jul 27, 2008 8:39 pm

warp2diesel wrote:

When you can climb a hill, tow a trailer, run the AC and comply with emissions with your two cycle model airplane engine, let us all know. Have fun flying

Is the fuel cheaper than printer ink :?:

To bad it's not a model plane engine,oh and it the fuel cost is $4.05(premium fuel) and a bottle of caster oil.

dkenny · **Posted:** Sun Jul 27, 2008 8:54 pm

I disagree with a couple of statments

GP don't help the engine start faster. I have 3 diesel engines. a liberty, cummins 5.9 and a detroit diesel 8.2 turbo..guess which start the fastest..right the detroit. no GP no electronics..now in cold weather it will take longer to start.

cooler air does help with the power..did ya'll forget that the liberty is INTERCOOLED!!! so is my cummins but not the detroit.

cold fuel...won't change things much. chttp://www.dieseltruckresource.com/dev/index.phpold biodiesel gells at will not work...

if you can keep the fuel at 50 or higher, espically for biodiesel all the better.

just my 2 cents

-dkenny

curtis · **Posted:** Sun Jul 27, 2008 9:05 pm

dkenny wrote:

I disagree with a couple of statments

GP don't help the engine start faster. I have 3 diesel engines. a liberty, cummins 5.9 and a detroit diesel 8.2 turbo..guess which start the fastest..right the detroit. no GP no electronics..now in cold weather it will take longer to start.

cooler air does help with the power..did ya'll forget that the liberty is INTERCOOLED!!! so is my cummins but not the detroit.

cold fuel...won't change things much. chttp://www.dieseltruckresource.com/dev/index.phpold biodiesel gells at will not work...

if you can keep the fuel at 50 or higher, espically for biodiesel all the better.

just my 2 cents

-dkenny

We were talking about fuel temp. Then some how we got onto CRD's being converted gas engines running on glow plugs like a model aircraft engine, and then we needed water injection to make our air intake denser :lol:

Your spot on dkenny,
Intercoolers cool down the compressed air from the turbo. The air gets extremely hot when compressed. For those that don't understand, drop by a shop with an air compressor running and grab ahold of the outlet pipe, just don't hang on to long. Then you will understand the theory.

Fuel Temperature

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