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Power FC Idle quality under electrical load

Steve

By Steve,
in Engines & Forced Induction

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Steve Grand Master

Steve

Posted
Posted

Hi,

Just wondering if anybody know if there is a setting to adjust idle on the power fc during electical load.

Idle quality is very good normally, and with AC on, but as soon as an electrical load is placed on the engine, such as turning on the headlights, the idle quality deteriorates somewhat, and the engine hunts by around 2-300rpm.

Idle is set at 950rpm, I have 256/264cams, sard 550cc injectors, bosch 044 fuel pump, Z32 afm.

I have tried adjusting the fuel correction (adding fuel) in the water temp menu, but this only makes the idle deteriorate further. I have tried pulling fuel and adding timing to get the idle stable, but then idle quatlity off load deteriorates.

Anybody have any ideas or experienced this problem before?

Cheers

Steve

Busky2k Veteran

Busky2k

Posted
Posted

Do you have any idea what your idle vacuum is like with the load? Esp with the cams...

Mine looses about 0.5mm/Hg from the base of 18 when the headlights is on... If you are loosing alot more vacuum, its something to think about...

Gav Mentor

Gav

Posted
Posted

Increase ignition advance for the bottom cells in the rev and load axis . Won't do any harm (detonation is very unlikely to occur in the region of 1000 to 1300 rpm and 1 to 3 load bands). Don't increase by more than 2 or 3 compared to neighbouring cells, however, as hunting will occur.

Keep a reference of these cells before you make changes and see how you go.

Cheers

Gav

Steve Grand Master

Steve

Posted
  • Author
Posted

thanks for the replies,

busky, I only get around 10-12in/Hg at idle, I am not sure how much it is effected by electrical load - on the map tracer, the load changes from 2 to 3.

Gav, I have already tried winding in more timing, with the result that idle is effected with once the electrical load has stopped, might just try winding in a bit more and see how it goes.

Busky2k Veteran

Busky2k

Posted
Posted

Wow thats not much idle vacuum. Didnt think the HKS cams woulda reduced it by that much..

crooser's suggestion is very good. Also check out the voltage under load with the lights and accessories on. Its funny how the PFC cannot actively adjust the idle if it drops due to one thing or another?

JasonO Enthusiast

JasonO

Posted
Posted

Steve,

Have you tried making adjustments in the menu where the rev limiter is, you can adjust the idle speed with AC load on the engine. It may help to lower the base idle speed slightly.

Are you aware that there is a routine to follow after initially installing the PFC which self learns idle parameters. Plug in the PFC, start the engine, idle with no load for 10 minutes, then with AC on for 10 minutes, then rear screen demister (I'd add headlights too) on for 10 minutes. Then drive for 10 minutes, switch off and idle characteristics should all be 'learned'.

I think this routine can be followed at any time after installing the PFC, you'll just need a spare 40 minutes, and something to read while you wait :P

Steve Grand Master

Steve

Posted
  • Author
Posted

Vacuum isnt too bad, I have had alot worse with previous cars that had bigger cams:) Owned a 351 with a 270 cam - that thing had no brakes below 1200rpm. I wouldnt be surprised if the settings for elec load is something that can be changed with Excel software - if worse comes to worse, I am pretty confident the signal tuner coming out in May will be able to sort it. But I would like to get it sorted before then.

I have tried adjustments through idle setting, but they only effect ac on and off. I have done the whole initial idle thing, but it wouldnt idle properly with elec load even after 10 minutes.

Cheers

Sydneykid Grand Master

Sydneykid

Posted
Posted

Hi Steve, it been a while since I adjusted it, but I am sure there is E/L correction for idle speed. I don't have a Commander at the moment, it is somewhere in Tasmania. So I can't check. Perhaps it is only accessible with the Datalogit software and/or maybe it is only on the GTR Power FC. If you have a Datalogit it is on the screen "Settings #1", if I remember rightly it's under rev limit rpm, then idle rpm, then A/C idle rpm and then E/L idle rpm.

When we get back from Philip Island next week, I will check it out and let you know.

Emre Proficient

Emre

Posted
Posted

The 'Idle E/L' is in the D-Jetro version of the Datalogit software.

Instead of adjusting the fuel settings, play around with the first window (0.64V) on the Air Flow settings.

Sard injectors also seem to be extremely laggy, did you try to add a bit more lag on the Injector menu...?

Steve Grand Master

Steve

Posted
  • Author
Posted

Dean, mesh fixed the idle, its not very good without load or with AC on - just with EL it gets a bit erratic, but nothing like it was even at normal idle before the mesh was added, it was bloody painful.

Emre, I think I have around 0.12ms in the injector menu, do you suggest more? I tired bumping it to 0.16 but it made no difference at all.

I really dont want to mess with the AF meter correction if possible, it really is a last resort. Plus, so far every time I mess with things under EL it just throws the idle out when the load is removed.

Perhaps I need a D Jetro:)

Emre Proficient

Emre

Posted
Posted

Adjusting a few % either way will not harm anything at 0-0.64V range, if it doesnt make a difference you can always go back to your original setting.

FYI, I have the Sard 700cc injectors and running +0.50 lag.

Last one, are you confirming that Idle E/L is present with MAF on Gts-T Datalogit...? On the GTR version, it only comes up when you select the D-Jetro version.

Steve Grand Master

Steve

Posted
  • Author
Posted

Cheers, I will have a play. Is that the normal sort of lag to use with sard injectors?

To clarify (sorry, last post was a bit vague), when I have changed any settings whilst an EL was pesent, to try and stabilise the idle, it messed with the normal idle - I also couldnt find any indicator in the sensor check function on the hand controller.

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