HI,

I was wondering why my tachometer (RPM) is affected (or it is decreasing) everyt ime i turn on my head light. I have 1992 spacewagon carb type. Guys, help me solve this problem. Thanks.

this hppens because the lights put a load on your battery, which puts a load on your alt, and that loads you engine. perfectly normal stuff

It is normal unless the lights really dim and brighten with RPM changes.
You did not mention if they did anything strange so I just wanted to throw my two cents in the hat. :)

Fullmoon,

Thanks for the concern pal, i really needed that, but that observation does not really end with the effect on my tachometer. Tachometer reading is an indication of engine revolution. I really wanted to set it up into 800 rpm during idling, tune up is done in the morning without considering the headlights. Im aiming, of course, TO SAVE GAS. But once I turned on the headlights in the evening the reading of tachometer or the revolution of engine decreases. Now Im afraid my wagon might get stalled. So what I did is to increase the setting. You know what comes next, it's the increase of gas consumption. What do you think sir?

bry940,

thanks pal, please read my response with FULLMOON, maybe you can further give comments on that. thanks again.

hi again,

i have looked at the manual and it shows that the idle adj is simply a screw on the throttle. The setting should be 750rpm +- 50. This will only effect your fuel economy when the vehicle is idling, it will make no diff when motoring.

With this in mind and remembering that the car has done a few years it i recommed setting the idle with the lights on (ie when there is a large electrical load)

There would be a slight increase in fuel consumption but a very very small amount.

To save fuel dont carry things you dont need in your car, service it and drive a little slower.

hope that helps

bry

thank you very much bry940. i think that's more than 2 cents in the hat