Does anyone happen to have any idea what their fuel consumption is at idle, in terms of gallons/hour? The reason I ask is, well, I filled up on Wednesday, and I'm nearing half a tank already (between 1/2 and 3/4) and its only thursday night, with about 40 miles on the odometer. My mixture screws are at 7 1/2 turns out, lean stop is at 5 turns out etc etc...
I've been playing around with it running, in park/drive for probably a couple hours since I filled up too, but heck I dont know if it's supposed to use THAT much fuel! I dont know, it seemed to get pretty awesome mileage before, but maybe I was running waayyyyy lean at idle with the idle mixture screws at about 4 turns out. It would buck a little bit, never could get rid of it till I backed out the mixture screws and readjusted my IAB. It was a little 'flat' on mild acceleration before too. Now it seems to idle just about right in drive at 500-600 rpms, and seems to pull harder on mild acceleration, so I'm happy with it in terms of running right. Motor is in my sig. Timing is at about 8 degrees advanced. TPS is set to .51V.

Also, if anyone wants to enlighten me on how to use the duty cycle function on a MultiMeter, please do. I've read the instructions and it doesn't clearly say how. I previously thought that I needed to use both positive and ground, hooked to the meter by the ground and the com (I think) port, but the readings were all over the place, very erratic. Then I tried just one probe on the very left port (cant remember without looking at it and its in my car), but theres no symbols or anything or the duty cycle. Anyhow, its getting long here, and sorry for that, but can anyone answer anything from this 'book'?

edit: Just wanted to add that it doesn't smell rich or anything at idle, seems to be about right. No strong fumes, smoke, etc.

Thanks,
Ben

 

My experience with suddenly high usage like that is that I didn't top it off quite like I thought I had. When averaging that fill with the next, my mileage goes right back to "normal" (I record mileage & amount added with each stop at the pump in a small spiral notebook kept in the console compartment - do that for all my vehicles).

Hook the dwell meter positive lead to the green harness plug by the heater/AC housing that doesn't go to anything, and negative to ground. Set the meter on the 6 cyl setting (I've never understood that, but that's what you do). The engine has to be fully warmed so it's in closed loop. Make a small adjustment and let it settle out b/4 making another adjustment.

 

Oh, and make sure you have all the vacuum lines either hooked up or plugged. Leaving the air cleaner base on with lid off for access to the IAB is a good idea (assuming you have a snorkel air cleaner with functioning thermovac).

 

five7,
I dont have a dwell tach, all I have is my multimeter with a duty cycle function. I've always read you can use the duty cycle and set it to operate at 50% in drive, wheels blocked. As for air cleaner, I have an open element, all unused vacuum ports on the carb are plugged.

Green harness plug by AC/heater housing.....I'll have to look for that one. Don't know that I've ever seen it. I always just back probed the plug (Blue wire) where it plugs into the MC solenoid plug on the carb.

The way I've had to set it before is to get the best idle, and the best throttle responce without 'gasping' before reving, but I'd really like to set it right. It always seems to have a fluctuating tach (+/- 100 rpms) anywhere but the setting I found last night, and even at that, its still slightly doing it. I thought it might be the cam, but it shouldnt be that big of a cam in a 350. Then I thought it might be my TCC, but the fact that I HAVE had it pretty smooth kind of makes me doubt that now.