JZX73 - Using power windows changes engine note...is that normal? :S

[beasht]

As per the title, I have had a 1JZ in my MX73 Cressida for probably about 4 years now and I have always had this problem but never given it much thought until now, mainly from curiosity more than anything.

What happens is that, when idling if I use any one of the power windows it changes the engine note. Even though I couldn't get hold of a wideband to hook up and have a look whats going on, I used my Apexi turbo timer with builtin A/F gauge to diagnose whats happening.

Rough results showed that A/F ratios richened from around 11.4 down to as low as 10.1. And I can't really be sure if it dropped any lower than this because Im not sure what the spectrum is of the stock A/F sensor?

Just wanted to get someones opinion about if this is normal or not?

[PlacentaJuan]

i think it will do the same thing if you turn the headlights on, turn a/c on also. the engine will be reving slightly faster to supply the extra power via alternator whenever an electrical load is applied.

[beasht]

no worries cheers for the quick reply
I guessed that with the aircon I just wasnt expecting that much load to be induced by the windows

[Vios-GT_07]

i always knew electrical load caused some strain on the alternator, but operating a window causes such a big gap in A/F ratios? man dun do anything during a dyno, that will screw up the map and 11.4 to 10.1? it should be at 14 during idle... that's pretty rich to be idling at in the first place (11.4)

[beasht]

thats it I thought it should be around 14.7 on idle, it does sit on that when driving around town when Im not accelerating, but it always sits on around 11-12 with the timer on for a minute or so.
haha thats the least of my worries Anyone at the SA Supra Dyno Day will know what I mean lol all I can say is that Im experiencing some pretty violent ignition breakdowns when revving above 4k :S but yeh thats a seperate problem
edit: speaking of which, a set of coil packs has just been delivered to my door

[ajh]

I had an XD Fairmont years ago, it was interesting to play with the power window switches and watch the Tacho move......downwards

Our SV21 does the same thing when the thermo fans cut in or high beam is switched on.

Seems normal.......

[Norbie]

It's nothing to do with A/F ratios, it's just the extra mechanical load imparted to the engine via the alternator (as indicated above) causing the engine note to change.

[beasht]

cool I thought it was going to end up being a pretty stupid question haha but I just wanted to make sure that the change in note was within normal limits and didn't point to something like my alternator starting to die
cheers everyone for the help

[mrshin]

Those little plastic dog A/F gauges are, well, completely and utterly useless. Completely ignore it.

[Vios-GT_07]

Those little plastic dog A/F gauges are, well, completely and utterly useless. Completely ignore it.

hm.. just so happen i'm thinking of getting one coz i plan to do a lot of high revving and i can't tell if it's running rich or lean.. (some people are gifted or experienced and can feel if it's rich or lean.. ) so i rely on the gauge.. and from what i gather, it has a stable 12V current (i believe it's ignition or something).. and it picks up A/F ratios in real time.. if the oxygen sensor is still good..

and yea note change is normal.. caused by loads and stuff.. but back to the topic .. it's safe and normal if the tone changes, but A/F fluctuations?? unless ur gauge is more of a volt-meter than an A/F gauge, i dun think that's supposed to happen..

[beasht]

the one I used was from my Apexi turbo timer, but as mrshin said I wouldnt be buying the turbo timer for the A/F gauge haha

[chris davey]

Any afr guage that relies on a narrow band o2 sensor is pointless. Even it it is still in "good" condition.

I agree with Norbie.

[Vios-GT_07]

Any afr guage that relies on a narrow band o2 sensor is pointless. Even it it is still in "good" condition.

I agree with Norbie.

does that include them 100 dollar autogauge / autometer gauge that comes with the oxygen sensor, and just require a bit of welding and wiring up to work? can't seem to find out if the gauges are wideband or narrowband.. but i'm assuming from what you mean that most of these gauges are narrowband, just because i notice wideband o2 sensor are quite expensive..

[chris davey]

yes it does. Innovative, PLX, techedge are a few companies that make proper wideband kits.

I have a techedge 2EO and it is great.

[beasht]

there expensive but well worth the money. I was looking at the AEM wideband setups, how much was the techedge kit Chris? That kit looked vry good aswell