Quote:
Originally Posted by 2000_HX_Civic
OH HEY!! BRUCEPICK, your Hx doesn't have a 1st gear or any gear 4k rev limiter right?...
|
Nah, no rev limiter. I've had it up around 6k. But I'm behaving now, keeping it usually under 2.5k and rarely over 3. Since the recent head rebuild, it runs nicely even at 1.5k so I can shift low and hear it grumble.
Just to let you know, you're not the only one with a cranky HX.
Mine has had some issues. Been driving it about 2 weeks since reinstalling the head. Still losing some oil, and lean burn is only intermittently available below 61 mph, almost always available above that. It's still a treat to see it go uphill at 40 mpg or better, when it's willing.
VTEC-E.
I'm only partially educated on this but my understanding is...
Aside from your computer apparently being messed up, which pretty much SNAFUs the whole thing, you probably don't need VTEC to work to get great mpg. Power yes, but mpg no.
Lean burn seems to be mostly controlled by the computer. How much fuel it "spits" being kept proportional to the amount of air, which it can read very well. The computer varies the air/fuel ratio according to however it's been programmed (duh) but the ratio varies with conditions. It reads air flow, and it also reads fuel and/or air in the exhaust gas with a wideband oxygen sensor.
Anyway, the VTEC-E setup letss the 2nd intake valve just barely crack open at "moderate" throttle settings. Just lets a little breeze get sucked into cylinder to help the mixture swirl. When you hit just over 3K rpm, the 2nd intake valve opens for real and you hear a change in engine sound. And if you have a good mpg gauge you'll see that drop. Regular VTEC on an EX or Si kicks in much higher, I'm told - like 5k or so. But the HX is made for fuel economy so it's different. I'm pretty sure the HX cam is ground for better performance at the lower rpms that the HX gearing allows, too.
I definitely recommend both a ScanGauge and an MPGuino. Getting both will set you back around $200 so maybe not this weekend.
But the SG will give you loads of engine operations info (including temp, voltage, in/out of lean burn, and open/closed loop status). And the MPGuino will give you real mpg numbers. I now feel naked if I ever have to drive the HX without them.