Fuel cooler after cp3 conversion

Dart.340

Canadian
Aug 3, 2015
30
0
0
Near Ottawa
Hey guys I was just thinking tonight about if it's a good idea to add a fuel cooler on my lml now that it has been converted to a cp3. I never gave any thought of this until repairing a fuel leak on a lmm at the cooler today and realized lml do not have a cooler. What is your opinion
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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ZEPHYRHILLS, FL
Not needed because the injectors don't return.
Everything I have seen still says that piezos work like traditional HPCR injectors, just that the piezo crystal control is much faster and more precise. I've only looked at pictures of LML injectors, but they sure appear to have a return line on them, and cutaway views show a traditional pressure differential style injector, just utilizng piezo crystal control instead of an electromagnetic solenoid.
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
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Wyoming
The LML piezo injectors still return fuel, obviously.

They just return a lot less fuel compared to electromechanical solenoid injectors on the 2001-2010 Duramax's....which is why GM decided it wasnt necessary to run a fuel cooler on the LML from the factory, because not much [hot] fuel is returned from the piezo injectors.

Ben
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
3,890
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The LML piezo injectors still return fuel, obviously.

They just return a lot less fuel compared to electromechanical solenoid injectors on the 2001-2010 Duramax's....which is why GM decided it wasnt necessary to run a fuel cooler on the LML from the factory, because not much [hot] fuel is returned from the piezo injectors.

Ben
In other words, the bean counters said it isn't required, but probably would have been a good idea. I still think LB7's return the most fuel of any of them each time the injector is fired. I know when I compared the internals of an LB7 to an LLY, there was ALOT of difference's inside them that lead me to believe the LLY's returned less per firing.
 

$chultz38

Member
Jan 22, 2009
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Everything I have seen still says that piezos work like traditional HPCR injectors, just that the piezo crystal control is much faster and more precise. I've only looked at pictures of LML injectors, but they sure appear to have a return line on them, and cutaway views show a traditional pressure differential style injector, just utilizng piezo crystal control instead of an electromagnetic solenoid.

Whoa I never saw that I didn't finish what I was trying to say...meant to say they don't return as much as previous gens.
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
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Wyoming
In other words, the bean counters said it isn't required, but probably would have been a good idea.

Ive never logged average fuel temps of driving an 01-10 truck with a fuel cooler, and an 11+ truck without a fuel cooler.

But it would be interesting to do that, before making a statement like that. ;)

The bean counters also have to answer to the engineers, remember...and the bean counters also have to take into account warranty stuff. If they save money by not putting a fuel cooler on, and it wears out fuel system components, they're going to be losing a lot more in warranty replacement costs............so longevity IS taken into count, even tho it might not seem so.

If you log both trucks side by side, and the fuel temps are roughly the same, what does it matter?