Fuel Injection on Decelaration
10-04-2007, 03:44 PM
#1
Member
Thread Starter
Join Date: Jun 2006
Location: Germany
Posts: 70
Hey,
my EMS is Power FC, i can set it up to do a Fuel Cut at deceleration (just like stock ECU) and i can let it inject fuel on decel.
What is safer and what makes more sense?
I have been told, that especially at highspeed driving, it should keep injecting fuel if i go off the throttle, to cool engine internals down etc.
In Motorsports, they often use injecting too.. but mayb for the reason of keep turbo spooling, too.
Have been also told, that many engine blows occure due to F/C at decleration, because engine runs to lean and hot.
Also i read somewhere on another forum (well the people were only up to shooting flames, but no other things..) that the extra injection on decel. wont harm the turbo at all.
Please tell me what you think and what you know
I want my engine to run as safe as possible. Since i am running highspeed runs also, i would like keeping on injecting fuel, if its true that that is a safer way.
my EMS is Power FC, i can set it up to do a Fuel Cut at deceleration (just like stock ECU) and i can let it inject fuel on decel.
What is safer and what makes more sense?
I have been told, that especially at highspeed driving, it should keep injecting fuel if i go off the throttle, to cool engine internals down etc.
In Motorsports, they often use injecting too.. but mayb for the reason of keep turbo spooling, too.
Have been also told, that many engine blows occure due to F/C at decleration, because engine runs to lean and hot.
Also i read somewhere on another forum (well the people were only up to shooting flames, but no other things..) that the extra injection on decel. wont harm the turbo at all.
Please tell me what you think and what you know
I want my engine to run as safe as possible. Since i am running highspeed runs also, i would like keeping on injecting fuel, if its true that that is a safer way.
10-04-2007, 04:10 PM
#2
Senior Member
Join Date: May 2002
Location: California
Posts: 22,465
its safe to keep injecting fuel on decel, well to a point where the back of the car's on fire...
you might want to set it up, so that in normal driving it does decel fuel cut, it'll save fuel
but if you're really running it hard then the extra fuel on decel will cool it down a bit, which is good
you might want to set it up, so that in normal driving it does decel fuel cut, it'll save fuel
but if you're really running it hard then the extra fuel on decel will cool it down a bit, which is good
10-04-2007, 04:17 PM
#3
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Join Date: Nov 2002
Location: PHX
Posts: 265
Not sure about running lean and blowing an engine due to fuel cut, if fuel is cut there is nothing to ignite or worse to pre-ignite. The added cooling might be a good argument, but with the small amount of gasoline being injected on decel how much cooling will there really be? I just run with the decel fuel cut on my PFC and have never had a problem with it.
10-05-2007, 02:49 PM
#7
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Join Date: May 2002
Location: California
Posts: 22,465
Originally Posted by zRotary' post='884592' date='Oct 5 2007, 12:40 PM
well, i dont have any backfires, and no fireballs. my Exhaust smokes as hell if fuel is injected LOL but no fire at all.
you sure? maybe its not hot enough?
10-09-2007, 01:03 PM
#10
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Thread Starter
Join Date: Jun 2006
Location: Germany
Posts: 70
well, yesterday i got some big flames, too big as i think LOL. at one point i could see the some flames threw the tailgate.
i want to keep injection on deceleration, but does it hurt my engine/turbo if i inject less fuel on decel.?
flames and backfiring ok.. i just dont care, but i am worried i get a melt bumper or even cought on fire!
what AFR should i get MAX. at decel.?
i want to keep injection on deceleration, but does it hurt my engine/turbo if i inject less fuel on decel.?
flames and backfiring ok.. i just dont care, but i am worried i get a melt bumper or even cought on fire!
what AFR should i get MAX. at decel.?