I have a lg4 with a cc QJet I just put on a 4 hole spacer (like a 3/4") I set the dwell at 30*. I hooked up an air/fuel guage I just purchased ,and at idle it is like right at lean ,and most of the time it is on the lean side. If i adjust it to get a little more on the normal side the dwell is up towards 45*.how could I get it a little richer. Could I adjust the TPS up alittle , I think it is at .54V. Would that richen it up, Im not sure. Or what else could I do.Also were should the A/F guage read at idle. Or should I just adjust it by the dwell (is that more accurate).
The vacuum is at 20 I dont think it is leaking
Any thoughts would be appreciated

Thanks

 

 

let me try it again ,only the keythings
1. If you can set your dwell at 30* does that mean your air / fuel ratio is were it should be at.(or what does it mean)

2. I got an A/F gauge it shows at idle it is kind of lean.

3. Should I rely on the dwellmeter or the A/F guage for my air / fuel mixture

Sorry if I am not making this clear, Im trying to learn all of this carb stuff as I go. Any input will help

Thanks

 

The dwell is simply the amount of time the ECM cycles the mixture control solenoid to keep the mixture at what it thinks is right. If the O2 sensor isn't sensing right, the ECM won't adjust properly, but usually that is in the other direction (rich) when the O2 sensor goes bad.

The only way you're going to change the way the ECM controls the mixture is to change the O2 sensor voltage that it thinks is "correct" - and you aren't going to do that, I don't think.

"Kind of lean" at idle is kind of a good thing from an emissions standpoint. The A/F gage use should be limited to verifying the ECM is doing its thing (which it seems to be), and WOT/open-loop tuning.

 

Thanks five 7 kid , you always come thru
Thats what I needed to know .
So as long as it is just at the first mark of being lean and not showing way lean it should be fine.
You learn something new each day, and if your lucky it will be something good

 

The spacer has esentially no effect on idle mixture. It may, or may not, affect WOT; the effect may be positive or negative. It depends on the rest of the air path above and below the carb, and the load on the engine (car weight, gears, etc.).

The "idle mixture adjustment screws" in the front of the throttle plate do basically nothing. Put them back at about 7 turns out and then leave them alone.

The carb is designed to idle lean, for emissions and gas mileage reasons. Too lean, probably, but that's a different matter.

To adjust the idle mixture, you use the IAC valve, which is in the top of the carb under a metal cover plate. It's about 7/16" in diameter, inside the air cleaner flange, at the very top of the carb. Pop the cover off, it looks like a huge brass screw. Adjust it in (CW) to richen the idle and low-speed part-throttle mixture to tend to be richer, and out to make it leaner. A little goes a long way so adjust it in small increments, like ¼ turn.