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Working on MPG

So the mpg by my math is 13.77. Last trip was about 11.75 so I am gaining. I noticed at the farm I had a 1/2 tin bumper with a lower deflector. May install it. It still needs a factory air cleaner with front ducting and a hot air tube. Plus I have a 195 thermostat to install.
 
I'd be curious to see gains from a factory air cleaner setup.

Martin
 
I agree martin I bet the cooler air charge will help some and cleaning the air up under the truck would help or at least do something.. I am stoked to hear you have it near 14mpg!! thats awesome man! I think your damn near as good as it gets, chasing your but on transitional circuits is really hard so write down every change and make single changes at a time now that your really close. that T stat should help some with the flat spot hopefully warming it up sooner.
One thing you might try is to set the initial a little higher, and go to a larger squirter..(covers lean spot initially) mind you with mine once I got the air bleed sized properly it changed everything. so messing with the emulsion circuits can put you back t square one.. you got it going damn good though..
 
Going to back the vac can of a half turn, I total is a tiny bit too much. Set the idle a/f to 16 last week. Accelerator pump seems pretty close. Bought a 6-32 tap and brass set screws to actually change the ifr. Probably grab a aircleaner and 2 hoses from u-pull-it to build a dual inlet. I still have the thermo switch for the heat riser so I will build 2 cans for the headers.
 
Well today was interesting. On the way to school headed into the wind (15-27mph) I could not sustain 70mph. It would lug slowly loosing vacuum till it would rattle then unlock the tcc. Then build vac, lock and repeat. Finally gave up and pulled it into drive. Not sure if the lean mixture has dropped the tq that much or if this much wind was always a problem (I don't really remember). Wonder if I should split the difference on my .012 and .005 wire when I actually jet the ifr. Hmmm. I do think even a small addition of a under bumper deflector would help it cut the air a bit better.
 
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well, a 20mph headwind would be the same as driving at 90... did you ever drive at that speed previous and how did it behave?
 
Well it won't stay in overdrive at 90/that is for sure.
 
I'm surprised it idles that lean to be honest. It might be the fact your not unlocking the TC under that semi light /moderate load is making it worse.. the thing I started to realize is these older autos are not smart enough to be in the correct gear all the time, tuning the carb around that is the wrong approach IMHO, I would unlock the TC earlier and let the engine have some revs a bit, your talking about a pretty good amount of load and trying to pull that at 1500rpm locked up and lean seems like it will not work without compromise elsewhere.
 
It may not be quite that lean at idle, it is pretty unhappy and it may be miss-firing a bit causing error. I had it set in the 15s before and did a quick reset after changing the power valve and ifr wire and haven't had a chance to fix it. The Tcc problem is kind of a bitch. The problem is it is a single point switch. So below the set point it unlocks but of course as soon as you decrease the load the vacuum rises above the set point. I have 2 factory vacuum delays but they really only slow it about 1-2 seconds. It really needs a switch with a high and a low so you can set a low point to unlock and it won't relock till you get to a high point. I had my EE buddies help me design a "latch" circuit with a second switch and relay but I haven't ordered another switch yet. We did talk about building a micro controller with an Arduino and a map sensor but, ya seems like a $1000 saddle for a $10 horse. Right now it will drop down below my 6.5inhg set point on some fairly mild hills that it wasn't before. I figured out that I made a pretty big jump going to the .012 wire (about 85%) of what it was before I am thinking of just going back to 80%. The rpms are a tad higher than 1500, at 1904 rpm for 65 mph and 2050 rpm for 70 mph. Either way I am mostly just playing and can go back.. I also bought air cleaner, 2 hoses and the round hose connectors that hold the hoses to the rad support yesterday. Hoping to build a dual snorkel air cleaner this weekend.
 
So I drilled out the .031 ifr and tapped the holes and installed 6-32 brass Allen set screws drilled with .027 holes. So now it is acting a bit goofy. Seems to be a lot richer. Sreidmx might be right and it might be pulling through the secondary ifr now. I will try drilling it out next week and replace it to see if things come back to normal.
 
That happened to me.. Such a pita to track down lol.. Like I said it whistled that's the only way I found it.
 
Going to drill and tap the rear ifr tomorrow. Just acts weird. Afr is 13.5-14.7 down low but now cruise is at 12.5 or so in od at 1850 rpm where with the wire I was seeing 15-16s. Not sure if changing the ifr also changes the rpm the jets come in but it is pulling at least 15 inhg so the power valve should be closed.
 
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