HIDS on cause AFR to lean out...

[kengeroo]

So I have always been running my HIDs on as DRL's. I have been tuning my car for a while trying to get the AFR's bang on. Today for some silly reason I decide to turn of the HIDs. As expected the idle/load changes and the AFRs richen up almost a full point (13i'ish).
I turn the HIDs back on and the car behaves normally as expected when an electrical load is turned on, and it leans back to 14.7'ish.

I am running power FC L-Jetro, was wondering if anyone has run into this before ?

thx

[caliber676]

Your electrical system must be strained from the lights or there's some emi (electro magnetic induction) caused from the ballast. I personally would take them out. But if you want to keep them, make sure your charging system is up to par and that your injector duty cycle is where it should be. It sounds like your injector duty cycle is shortening when the lights turn on, which by any means is a problem. You don't want a good afr with lights on and god knows what when they're off

[Skym]

It's the voltage varying to fuel pump. When light's are on it should drop voltage to fuel pump hence leaning out. When light's are off it should provide more voltage to fuel pump hence it runs richer. I have mentioned the amount (voltage) it drops by in the past (can see voltage drop on turbo timer). It's normal and is why you compensate for this via running engine richer than it needs to be with ECU tune and hardwiring the fuel pump helps.

Also PowerFC has the self learn idle feature that compensates for light's on, off and aircon on, off, etc. Sounds like you need to run the self learn idle feature (usually done before tuning ECU, so might need to copy maps off ECU via tuning software and reset ECU, do the self learn idle feature and reload maps back onto ECU). Best to ask one of the experienced tuners on here to confirm if it's the best course of action and if they can help you.

Also ECU's do have compensation based on voltage, so would double check those settings on PowerFC (I think can only access via tuning software, not available on hand controller).

[kengeroo]

yep sounds like the re-initialize is in need ....thx !!!

i suppose no one knows the lag and duty cycle for deatchwerks 1100cc injectors ???

[Skym]

You're welcome. From memory aircon causes the biggest voltage drop, stock light's cause a minimal drop.

When you resize injectors it should adjust fuel map (including duty cycle) to suit.

Lag should be able to be worked out via using this calculator -

http://www.deatschwerks.com/battery-offset-wizard

[amnash]

It's the voltage varying to fuel pump. When light's are on it should drop voltage to fuel pump hence leaning out. When light's are off it should provide more voltage to fuel pump hence it runs richer. I have mentioned the amount (voltage) it drops by in the past (can see voltage drop on turbo timer). It's normal and is why you compensate for this via running engine richer than it needs to be with ECU tune and hardwiring the fuel pump helps.

Also PowerFC has the self learn idle feature that compensates for light's on, off and aircon on, off, etc. Sounds like you need to run the self learn idle feature (usually done before tuning ECU, so might need to copy maps off ECU via tuning software and reset ECU, do the self learn idle feature and reload maps back onto ECU). Best to ask one of the experienced tuners on here to confirm if it's the best course of action and if they can help you.

Also ECU's do have compensation based on voltage, so would double check those settings on PowerFC (I think can only access via tuning software, not available on hand controller).

just hard wire fuel pump?

[Skym]

just hard wire fuel pump?

That part was when light's, aircon are on and engine is on boost (voltage drops due to ignition system, light's, aircon, etc) and have upgraded injectors like his car has, etc (drops from over 14 volts to 13.5 volts which aftermarket fuel pumps need). Hard wiring fuel pump, running engine richer helps to prevent engine going too lean due to drop in voltage to fuel pump.

If voltage stays steady to fuel pump and rises when needed (on boost), can get more hp from smaller injectors, as don't need to open them more when on boost, etc to compensate.

That's what this device does -

http://www.kennebell.net/KBWebsite/Accessories_pg/Boost%20A%20Pump/layouts/boostapump.htm

But is not as reliable, cheap as hardwiring fuel pump.

I think the voltage compensation on ECU (I gather idle learn feature adjust's this automatically) might be the best way to solve the idle problem, as ECU adjust's injectors based on voltage.

[kengeroo]

So I have been in contact with Deatchwerks asking about lag times on my 1000 cc injectors...
Back in Nov 2011 they gave me a set of values to use,,, Today I go on the web page and find a different set of values, about 50-80% lower than the old ones.. I verified with them that yes, the new values are correct and were changed due to new tests they ran, or something...

Untitled.bmp

Does anyone have a guess on what performance/change/gains will occur with the new lower lag values ? And I'm assuming that I will have to retune my INJ map, as my AFRs went Jenny Craig lean when I used them...

thx !

[nismo-152]

Im not sure this would be an issue and depending on placement but dont the ballasts give off RF interference that can disrupt small voltage signals...?

[kengeroo]

according to my mechanic it's the Idle control valve,,,
from what he told me, I figured the lag values would resolve the issue..



"There's an electrical load signal circuit built into the ecu.

The idea is when there is high electrical load (alternator at full tilt) the idle up valve is activated. So idle doesn't drop too low. When the valve opens the mixture will lean out a bit.

When the cars running it's constant at 14 volts, the latency table is to compensate for lower voltage while cranking. Let me see, think I have the values here too"

[kengeroo]

grrrrr... tried a re-init of the powerfc,, ilde for 10,,, lights for 10,, ac for 10,, etc...
no dice still goes lean with the HIDS on...

what about deleteing the IAV ?

[kengeroo]

for the love of GOD,,, someone tell what's wrong...
I have a gooder idea now

This is what happens when I turn on these electrical loads..

Fan blower motor only AFRS richen up
Rear defrost only AFRS richen up
AC only AFRS richen up
HIDs only AFRS lean out

Would this not point to something in the HID wiring ??

I was monkeying around with the idea about the relationship with the ECU and A/C..
Does a power FC not compensate for the huge load that the A/C puts on the whole system,,, raising RPM and stabilizing everything ??? A/C on seems to mack the AFRs rock solid...

I'm going to do some test tommorow,,, but I was thinking if when the HIDS were turned on it triggered the A/C on pin on the ECU it would fix this ??/ (or band-aid it)

[kengeroo]

Hey !
next time your skyline turn on some electrical loads (headlights, defrost, etc...) and let me know what happens to your AFR's

thx!

[kengeroo]

ANSWER --- 95 r33 gtr didn't relay the headlights... ,, slapped in a relay,, all good now !!