update: my poor mpg crx hf

[FiShNc]

This is just an update on my intro thread here: http://ecomodder.com/forum/showthrea...tml#post399117 I figured the follow-up is more appropriate here since it's getting deeper than just "hello, this is what I drive."

My last tank gave me only 30mpg. I've now adjusted the valves, inflated the tires a bit for cold weather, and cleared some stale codes left in the ECU after I fiddled with the eacv and TPS.

I doubt my mpg was affected that much by the valves, especially since they were all in various degrees of within spec. I set them all in the middle of the spec range, so the next bigger feeler gauge wouldn't slide in.

I also doubt the stale ecu codes had anything to do with it. I never had a CEL, and yes, the CEL lamp works.

However, after doing valves, I decided to double check timing. It was about 25 btdc! Odd because, I had it nailed down at 16 in the summer. I'm surprised I never had ping! Anyway I set it back to 17 btdc. I figure 1 degree advanced over spec is probably good, since I got away with 9 for I don't know how long. I'm willing to believe my timing had something to do with my poor mpg. On standard pump gas, I bet 25 degrees is enough to start seeing some power loss.

I also think my driving habits might be playing a huge role. That last tank was zero highway, and my daily commute is 9 minutes with traffic. Basically, the car never warms up, so even with my problems fixed, it never runs in closed loop. Perhaps it's time to move farther away, commute by bike, or look at an engine heater. We'll see if the next tank shows any results from the most recent tweaks.

Incidentally, when I was doing valves, I pulled the plugs and noticed #1 looked a little rich. 2, 3, and 4 were all nice. I'm running some Techron to see if I can even out the fuel distribution. I know that's a terrible solution, but I had a half bottle so I just threw it in. I've also just today noticed the return of bouncing idle. Time to investigate vacuum leaks and coolant bubbles again. Ugh. It never ends.

[spacemanspif]

Originally Posted by FiShNc

That last tank was zero highway, and my daily commute is 9 minutes with traffic. Basically, the car never warms up, so even with my problems fixed, it never runs in closed loop. Perhaps it's time to move farther away, commute by bike, or look at an engine heater. We'll see if the next tank shows any results from the most recent tweaks.

Get a bike lol. How far is the commute? If its too far for a bike, get a scooter or moped and some heavy cover-alls to keep you warm.

[user removed]

Replace the thermostat. It should warm up faster than a 9 minute commute. Is your temp gauge not showing a warm up (staying at the bottom of the range). Without coolant temp in specs the cold fuel enrichment will not stop. I can get my Fiesta above 40 MPG in the first 1.5 miles (about 2 minutes) of my typical drive (don't commute).

OE type Japanese thermostats usually fail wide open, so the symptoms are the same as no thermostat.

regards
Mech

[FiShNc]

Yeah I just replaced the thermostat. Temp gauge used to be pegged at cold all the time. It warms up now but it takes just a little longer than I usually drive.

[samwichse]

Winter grill block time

Shove a couple lengths of pipe insulation in the lower grill and be done with it. I drive a Civic hybrid on a low speed (but 10 mile) commute. With the heat off, cold day, and no grill block, I'll be 6 miles in before ECT hits the thermostat opening temp. With the grill block, it's about 4 miles and then I can turn on the heat.

[FiShNc]

Originally Posted by spacemanspif

Get a bike lol. How far is the commute? If its too far for a bike, get a scooter or moped and some heavy cover-alls to keep you warm.

That's kind of my number one option right now. But snow could present some occasional problems. Maybe I'll do that, plus a winter grill block for snowy days.

[Superfuelgero]

More than you ever wanted to know about the Honda IACV - Gas Savers - Fuel Efficiency Forum

Also try re-learning the idle

more info:
Hunting idle when headlights on - Honda-Tech

[FiShNc]

Xntrx, that's a great explanation of Honda idle systems. Not surprising i guess considering the source. I'd say it's a must read for anyone with idle problems. Thanks for that.

[aerohead]

I'm driving my 1st-gen HF again and if I do just the 7-miles from home to here where I use the computer I'm seeing no better than 34-mpg (tank mileage).
If I top off and hit the highway at the old 55-mph speed,she'll pull 52-mpg 'naked'.
The stop and go and short commuting never allows the the car to reach equilibrium warmup conditions.

[slownugly]

block heater!!