Questions about resistors, gonna try an experiment Options

[jsayre914]

I was reading the D-Jet Brad Anders and came across the part about the aux air regulator. I will quote from his site:

Does Yours Close Too Fast?: If you'd like for the AAR to stay open longer, try adding 2.5 ohms (four 10 ohm/10W power resistors in parallel) in series with the heater. This will reduce the heater power from ~14W down to ~10W, and cause the AAR to close more slowly. Should add a few minutes to the fast idle part of the cycle. Please exercise caution - that resistor pack can get hot, make sure it is safely secured.

My 2056 runs pretty rich on cold start, the aux air valve is working as it should, I tested it 14.2ohms and put it in the freezer, it opened all the way, then put it in a ziplock and submerged it in boiling water and it closed all the way.

I noticed that the idle drops pretty quick, like within 2min it is below 1000rpm. I was going to try to slow down the aar closing so i could get a good 5min or so before it drops. I tried to just unplug it because the valve will close by itself with just the heat from the engine. This kept the idle up for more much more than 5 min.

So teach me how to drop the voltage from 14.4 to about 10v

I dont want to melt anything, start a fire, or screw with the same circuit the fuel pump is running on. What do i buy, where do I buy it and what do I have to do to make my idea work.


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I have an 250ohm resistor in the garage from a 2.0 liter cht sender that would fit perfect in line, would that work (IMG:style_emoticons/default/rolleyes.gif) (IMG:style_emoticons/default/beer3.gif)

[Dave_Darling]

250 ohms is a whole lot more than 2.5 ohms. I suppose if you get 100 of them together, you can wire them up in parallel... At 250 ohms, you would get something on the order of 0.5V to the heating element, which will take approximately forever to heat up to the point where the valve closes.

(Note that you'll always have heat coming from the motor itself, so that places an upper limit on the amount of time the valve can be open.)

If you put 2.5 ohms worth of resistance in there, it will have about 1 amp running through it. That's a lot of power, and you need to make sure to get a resistor that can deal with it. I don't think there are many 2.5 ohm - 6.25 Watt resistors out there, so your best bet is to put together what Brad said.

Find a handful of 10 ohm-10 Watt resistors. Hook them together in parallel. That being, all of the one end of the resistors are hooked together, and a wire goes from there to the connector on the AAR. All of the other ends of the resistors are hooked together, and a wire goes from there to the power wire that plugs into the AAR wire. Yes, insulate the connections.

Dissipating 10W of power means the resistors will get kind of warm. You might want to make the wires somewhat long, and put the resistor pack away from stuff that can easily melt or that you're going to be putting your hands near.

--DD