Evoscan full trims help
Sep 17, 2013, 06:03 AM
#1
Newbie
Thread Starter
EVOSCAN fuel trims need help
hello i want to check if i'm logging proper fuel trims or they are just stuck on the same values all the way
Last edited by nicolassabra; Sep 17, 2013 at 06:42 AM.
Sep 17, 2013, 11:40 AM
#4
Newbie
Thread Starter
Sep 17, 2013, 03:47 PM
#5
You mid trim is okay, low trim need some tuning. And yes you could adjust MAF compensation but you're playing with load which is related to many other variables and tables. I suggest (consensus) that you reduce injector latency. Reduce it a little bit and test.
Sep 17, 2013, 11:56 PM
#6
Newbie
Thread Starter
SO u don't suggest decreasing my m MAF scaling table values by 9% from 19 hz till 1610hz without messing with maf compensation and injecor latency?
Sep 18, 2013, 08:49 AM
#7
And as I said you don't need to reduce MAF scaling unless you really need to rescale your MAF for a new intake or an issue. If you adjust MAF scaling you'll play with load variable which is related to fuel calc. The little problem (if any) is that load is also related to timing, many compensations, many subroutines.
The best way to adjust trim is by only affecting the fuel variable. This is where injector scaling and latency values come into play.
Your low trim is -6,8 and mid is -0,78. I suggest that you reduce latency a little bit at the time and see what happens to your low trim. Keep an eye on STFT while doing that.
Think of it like this:
If you reduce latency, ECU will say ok my injector react faster so I need to open injector for a shorter amount of time ( result is less fuel )
If you reduce injector scaling, ECU will say: my injectors are smaller so I need to open them a longer time ( result is more fuel )
Latency is the injector reaction time when signal is sent. This variable will theorically affect all loads, but it will only be perceptible at very low loads, when ECU injects a little amount of fuel. Effect on WOT fueling is like adding a single glass of water in a lake: AFR will remain quite the same. But add this same glass of water in a bottle, final AFR will be much more changed.
Scaling will affect all fueling situations. Rescaling injectors often mean readjusting latencies.
Last edited by domyz; Sep 18, 2013 at 08:52 AM.
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Sep 18, 2013, 11:45 AM
#8
Newbie
Thread Starter
I'm not sure where your 9% come from?
And as I said you don't need to reduce MAF scaling unless you really need to rescale your MAF for a new intake or an issue. If you adjust MAF scaling you'll play with load variable which is related to fuel calc. The little problem (if any) is that load is also related to timing, many compensations, many subroutines.
The best way to adjust trim is by only affecting the fuel variable. This is where injector scaling and latency values come into play.
Your low trim is -6,8 and mid is -0,78. I suggest that you reduce latency a little bit at the time and see what happens to your low trim. Keep an eye on STFT while doing that.
Think of it like this:
If you reduce latency, ECU will say ok my injector react faster so I need to open injector for a shorter amount of time ( result is less fuel )
If you reduce injector scaling, ECU will say: my injectors are smaller so I need to open them a longer time ( result is more fuel )
Latency is the injector reaction time when signal is sent. This variable will theorically affect all loads, but it will only be perceptible at very low loads, when ECU injects a little amount of fuel. Effect on WOT fueling is like adding a single glass of water in a lake: AFR will remain quite the same. But add this same glass of water in a bottle, final AFR will be much more changed.
Scaling will affect all fueling situations. Rescaling injectors often mean readjusting latencies.
And as I said you don't need to reduce MAF scaling unless you really need to rescale your MAF for a new intake or an issue. If you adjust MAF scaling you'll play with load variable which is related to fuel calc. The little problem (if any) is that load is also related to timing, many compensations, many subroutines.
The best way to adjust trim is by only affecting the fuel variable. This is where injector scaling and latency values come into play.
Your low trim is -6,8 and mid is -0,78. I suggest that you reduce latency a little bit at the time and see what happens to your low trim. Keep an eye on STFT while doing that.
Think of it like this:
If you reduce latency, ECU will say ok my injector react faster so I need to open injector for a shorter amount of time ( result is less fuel )
If you reduce injector scaling, ECU will say: my injectors are smaller so I need to open them a longer time ( result is more fuel )
Latency is the injector reaction time when signal is sent. This variable will theorically affect all loads, but it will only be perceptible at very low loads, when ECU injects a little amount of fuel. Effect on WOT fueling is like adding a single glass of water in a lake: AFR will remain quite the same. But add this same glass of water in a bottle, final AFR will be much more changed.
Scaling will affect all fueling situations. Rescaling injectors often mean readjusting latencies.
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