Higher than normal load to maintain speed = bad MPGs
#1
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Higher than normal load to maintain speed = bad MPGs
So the car is back on the road and I noticed something pretty quickly today. While driving at highway speeds, 60mph+, it seems my load required to maintain a constant speed is higher than it should be. Normally, I'd be looking at 16-12mmHg of vac. while holding speed. Now I'm in the 11-9mmHg range on the gauge. This might not sound too bad.... or maybe it does. It has also caused me to go through 1/2 a tank of gas in about 100mi. of highway cruising, far more than normal.
Car holds normal vac. at idle/decel.
AFRs are good (dither between 14.6-15.2 when crusing).
No obvious problems anywhere else.
Not leaking fuel anywhere.
Halp?
Car holds normal vac. at idle/decel.
AFRs are good (dither between 14.6-15.2 when crusing).
No obvious problems anywhere else.
Not leaking fuel anywhere.
Halp?
#4
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Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,850
Total Cats: 71
IIRC we checked that before installing the engine and all was well.
I've noticed that pretty much under 3k RPMs in any gear, that holding 10mmHg causes me to accelerate- as seems correct- while 18-16mmHg would hold a steady speed. But on the highway, anything above that RPM level, 10mmHg is holding a steady speed. Might this come down to ignition advance timing? Might more timing help with this?
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Greasyman
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09-28-2015 10:44 AM