Hx getting 32 Mpg =\

[Ryland]

Before replacing the ECU try running a full tank of gas and check your mileage as it sounds like the tune up might have helped it run a great deal better and if I'm reading it right it sounds like the V-tec problem you are having is only going to show it's self when you are trying to merge in heavy trafic or other times that you want a bit higher reves and more power, thus it might be a non issue 99% of the time.
Also if it is the ECU it looks like you can buy a brand new one for $642 Honda Automotive Parts
Prices for stuff like that from the dealer can vary a great deal so I find it best to look at online dealerships to find easy to ship dealer only parts.

[2000_HX_Civic]

That is exactly my idea I filled up last night.

I'll be doing a good deal of driving this weekend, so I'll have the results at the latest Sunday, meaning 200 miles or so.

I'm unsure about the whole 99% of the time my Vtec-e problem not affecting me. I get that Vtec activates in the mid-range of the powerband, but the Vtec-e is a bit different, I do believe.

The way I understand the Hx is that it goes into "lean mode" Because of the timing/ecu/vtec-e.

And as stated the truth is i've never WOT the car. it's ment for 40+ mpg.

I hate to say this, but my dad owns a Toyota Supra 95' with 4 some odd thousand miles. I get to drive spirited in the summer time with a car that is designed to preform.

I really may be misunderstanding about my ecu problem and my mpg

Soooo, i'll see what kind of mileage I can get now with a brand new and properly installed timing belt.

As for the huge discount on the ecu, that's what Magauto is.. I appreciate the link to Hondaautomotiveparts,

but for better or worse Magauto owes me a favor. I replaced the clutch on the car when I got it, IT WAS BAD! practically refusing reverse

I ordered OEM HONDA clutch kit more less. I paid for fast shipping and when the package arrived............ all there was in the box were mudflaps.......mudflaps....MUDFLAPS they really did a number on me.

As calm as I could called them and got reimbursement for the products and the special shipping

My point is the sales woman promised me a special discount on any and all products if I ever decide to order again.

They have the ecu, for $660, the bonus is that part is stated as the California Hx version. With the discount it should be below any other competitor.

The more I get into this the more I just want a completely new ECU and to be done with it (Ideally FOREVER!!!!) especially since the part is next to half off.

[some_other_dave]

Unfortunately, many of the "limp home" modes will not only limit the RPM range, but they will also run the engine rich just to make sure to avoid detonation/pinging which can damage the engine. That isn't so great for fuel economy.

I think that the VTEC-e system is for fuel economy as well, so if it's not working that will probably hurt your mileage too.

-soD

[brucepick]

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.

[caeaves]

I don't think there was any ECU protection for that model civic.

all HX had the ability to "lean burn" only difference is that the California model had a different ecu.

this is the california ecu's part number 37820-P2N-L31 and the 49 state ecu 37820-P2N-A31.

So something is different.

Also found one on ebay for 90 bucks.


://cgi.ebay.com/ebaymotors/2000-Honda-Civic-HX-ECU-Engine-Computer-Unit-Module-A32-/140511820324#ht_500wt_749]2000 Honda Civic HX ECU Engine Computer Unit Module A32 - eBay (item 140511820324 end time Mar-14-11 17:39:56 PDT)


Here is the list of all the Civic Ecu Codes as well.


Code: OBD: VTEC: Found In:
P05 1 no 1992-1995 Honda Civic CX
P06 1 no 1992-1995 Honda Civic DX
P07 1 yes 1992-1995 Honda Civic VX
P08 1 yes 1992-1995 Honda Civic D15B (JDM)
P27 1 yes 1992-1995 Honda Civic EG JDM1600 SOHC
P28 1 yes 1992-1995 Honda Civic EX/Si / del Sol Si
P2E 2 no 1996-1998 Honda Civic DX
P2M 2 yes 1996-2000 Honda Civic (NZ) SOHC VTEC
P2N 2 no 1996-2000 Honda Civic HX
P2P 2 yes 1996-2000 Honda Civic EX (D16Y8)
P2T 2b yes 1999-2000 Honda Civic Si
P30 1 yes 1992-1995 Honda del Sol DOHC VTEC EG/SiR

[Pendragon]

Originally Posted by caeaves

<snip>

Also found one on ebay for 90 bucks.


://cgi.ebay.com/ebaymotors/2000-Honda-Civic-HX-ECU-Engine-Computer-Unit-Module-A32-/140511820324#ht_500wt_749]2000 Honda Civic HX ECU Engine Computer Unit Module A32 - eBay (item 140511820324 end time Mar-14-11 17:39:56 PDT)
<snip>

Link

[caeaves]

Thanks, I am unable to post links just yet. Going to look at an HX today and found this forum in the process. Can't wait to really get involved.

[2000_HX_Civic]

OK, so I've drivin the car 232 miles since my last full tank, I just bought gas and my tank took 6.4 meaning my average mpg turns out to be 36.


36! Here in chicagoland we've had crazy 40+ mile an hour winds WHICH I can only imagine kills mpg's. plus at time i had like 300 lbs in the car.

So, so far since my timing belt has been replaced I've gained 4mpg.

I'm excited to see what my next tank will get, i'm hoping for 38.

As for my ECU/ECM the Honda dealership I went to wrote down the part number as #37820-P2N-A33,

but if you go on Magauto's web site after you click on honda and find parts 2000 civic go under Electrical, Ignition system, Ecm, manual trans

you'll see that it is broken down to Federal, and California.

If you type in part #37820-P2N-L33 it is specifically listed as 99-00 California Hx ECM

part #37820-P2N-A33 is just listed as 99-00 Federal hx ECM.

I am not going to try the ebay ECU, at first I was excited, but the last number and letter are different.

I whole heartedly believe I need the L33.

My thought as to why the Honda guy wrote down A33 is because he is unaware that my specific civic is a Californian version.

Anyone agree with me?

[vskid3]

Under the hood, probably on the hood, there should be a sticker about the emissions and whether it is federal or CA. If it isn't there, you could probably run the VIN through a decoder and probably find out for sure.

[some_other_dave]

...And you can probably find the part number on your ECU...

-soD