lca13's 93 California VX Thread

[lca13]

Questions. Questions. I decided to just start my own thread for questions and any feedback I can give on things... I am a complete novice so far so I expect more of the former at first (although my shop vac thread idea wasn't too bad... :-)

So, first two:

Idle gallons per hour... I have seen figures for cars from 0.1 to 0.5 gph... anyone have an idea on a VX? FYI, mine idles very low... 300-400 RPM's... nice. Context is coasting engine off versus engine on in neutral... the latter seems much easier.

Mirror... how do I remove the driver's outside mirror? It looks to me like the plastic bolt cover on the inside of the car s removable, but it is not obvious how to do it (at least to me).

Thanks all..... this is the best site. Lance in the Bay Area

[Matt Timion]

Hey Lance... for the GPH I have no idea. It's probably in the shop manual somewhere.

I'm pretty certain that removing the drivers mirror is illegal. IMHO it wouldn't provide statistically significant gains. You'd be better off with a grill block, partial underbelly tray, or wheel well covers.

Glad to have you here :)

[lca13]

I have installed a side mirror in the inside and have been using that... the area of the mirror is nearly 5% of the total frontal area so I am interested in at least trying things with it off (some of the other stuff I alread have installed)

[TomO]

The door panel should come off for ease of removal for the side mirror. there is a screw in the upper/forward part of the door card that is covered when the door is closed by the dashboard. There is a screw in the bottom of the door cup/handle you use to pull the door closed. There also may be a screw or two (can't remember at the moment) inside the speaker grill area. The last screw is under the interior door handle, pull open the interior handle to access the screw. Then just pop off (pull from the upper most part) the small triangle of plastic covering the nuts that are holding on the side view mirror.

[James]

I was thinking about doing this with my vx, except just for the passenger side mirror. Is there a special block off plate that these cars have when they didnt come with the passenger side mirror from the factory?

[lca13]

Front Brakes Sticking.... finally jacked the car up and tested all the wheels. The front's were quite bad... maybe five pounds of force to break the friction then of course they would stop in a quarter turn.

I pulled the wheel and eventually pulled back the caliber. After a couple of times on manually trying to retract the piston an additional distance, I opted to pop the piston out to see what was going on. Sure enough some crud and an ridge in the back of the caliper cylinder. I cleaned it up as best I could (although didn't try to shave the ridge down) and put it back together.
After the bleed and all, it is quite a bit better, but still sticking some...

Question is: take it apart and sand the ridge down? or just get some remanufactured loaded calipers... or of course, go to the mechanic :-)

[TomO]

James: There is a factory block off for the passenger mirror-
http://www.hondaautomotiveparts.com/auto/jsp/mws/catimgs/13sr30_h14.gif
#13
76221-SR3-000 COVER, R. DOOR MIRROR (FENDER MIRROR) $3.45 At [San Leandro Honda Parts (http://slhondaparts.com/browse.asp)

There may be a Japanese counterpart for teh driver's side as well, but I haven't searched for it yet.

lca13: Best to bite the bullet and get a replacement (rebuilt) caliper.

[lca13]

Thanks to TomO, I now have a non-CA VX ecu and o2 sensor. Trouble is that I am now scared to death to touch any 15 year old engine compartment wiring.... :-)

Oh well... since I have no clue as to doing this conversion, I want to work this out on paper before opening the hood.

1st question... can I just swap ecu's and nothing else and be OK? Or will it act weird w/o the 5 wire O2 (and I've seen comments about an EGR on the 49 state model as well).

Help, before I break something :-)

[TomO]

Can you get a hold of a digital camera and take a snapshot of the firewall? I ask because you make it sound like you don't have an EGR on your CA VX, is this true?

Don't plug in the 49 state ECU into the harness just yet. there is a thread on here by Matt or somebody on the pinouts of the O2 for the 49 states model. you'll want to get those wired up first.

I would be more helpful right now, but I'm in the middle of proctoring a state issued test to the kids.

Glad doing business with you to. :)

[lca13]

Kids come 1st. Hats off to all you teachers.

I am gonna go real slow on this swap out. Like I said, 15 yr old wiring scares me. Plus I am in the middle of this totally fun aero experiment (getting the back end ready to support a high pressure fan blower.... hee hee!

[James]

Cool,
i'm going to try that passenger mirror blockoff. I put in the new cap rotor and wires in mine and it idles smoother...way down to 550. I like how low it idles. I am waiting for the o2 sensor to see if that fixes the lean burn miss.

lca 13, wish i could help more i am still learning about this efficient yet sensitive car.

[lca13]

OK, back to thinking about the lean burn addition. Someone suggested the CA VX's don't have an EGR, but I just saw what sure looks like one in the right place. I also poured over the schematics last night and came to the conclusion that the 5 wire O2 and the 4 wire basically overlap in their connections (not fully sure but it looks like it). This has me thinking I can swap in the 5 wire O2 w/o any other change..... maybe.

One thing also is that the 5 wire O2 pig tail harness is significantly different than the 4 wire.... not the same with a missing wire for example, so that is another complication.

[Gary Palmer]

Your assesement on the wiring is correct, their are several wires which are common. However, in order to switch in the 5 wire, you need to have a ecu which is built for the 5 wire. The 49 state, manual transmission has a special ecu, which has 2 processors, one which controls just the 5 wire sensor and one which runs the engine. I don't know if you could just add the ecu and the 5 wire, to your existing engine, but I believe you could, technically. I don't know how it might work because the mapping in the ecu is for a different cam profile than what is in your engine. It might work Ok, which is what I suspect, but it might not, which is what other people probably suspect.

Good Luck. If you decide to make these changes, please be sure to post it and let everyone know how it goes. I have an 89 and a 91 that I have considered this as one possibility, for.

[lca13]

Yeah I have both the 49 state O2 and the ECU... so an attempt could be to wire up the new O2 to match the existing wiring, get the 5th wire to where it needs to be, drop in the other ECU and start it up.....

Should I try this?

[Gary Palmer]

If it were me, I would be inclined to try, but I dangerously like to fiddle, which sometimes creates a lot more grief than not. You could just make a 5 wire adapter, and make it so you can plug into the 4 wire connector. Then you could switch back and forth with pretty much no risks.

[lca13]

After pouring over the schematics, I came to the conclusion I could just swap out the VX California ECU and drop in the 49-state ECU... the only difference I could see was O2 related.

So I did, and the engine started up, seemed to run fine... I drove it around for a while and everything was good. I do have a CEL which was expected... and the diagnostic code was encouraging: 41 - primary oxygen sensor heater.

So at this point I suspect I am running in open loop, but running .... and just waiting for the 5-wire O2 install. (figuring out how to map the 5-wire to the existing harness will be a little bigger challenge though).

[Telco]

Hey, on the brake issue, don't screw around. If you have a ridge on the piston, you'd be a lot better off just getting 2 new calipers. This is the simplest way to fix the problem correctly. Well, the simplest way would be to take it to the mechanic, but that would cost a whole lot more than a couple of new calipers will.

Before installing new calipers, I'd suggest getting the brake lines flushed out. If you have crud in the calipers you likely have crud in the lines which will quickly find its way to the new calipers. If you have ABS it's best to have this done by somebody that can command the ABS module to cycle, otherwise the fluid inside the ABS unit won't be flushed. Otherwise, just get a vacuum bleeder and start draining, keeping the reservoir filled, until you see clean fluid coming out. Two other things to do, change all the flex lines and use DOT4 fluid. The flex lines deteriorate from the inside, and will look perfectly fine on the outside. DOT4 has a higher boiling point, so will reduce brake fade. If you use stainless flex lines, you will get a much better pedal feel.

[lca13]

So I did replace the calipers a while back, but I still had some brake stickage... much better than before but some still. I re-bled the lines last week to see if that helped (noticed some sponginess from the 1st bleed).... maybe better yet (heck, my last tank was 58 mpg... 4 better than ever), but if I spin the wheel, the pads are still dragging.

Just how free should a disk brake setup feel? The drums in the back show zero drag... the wheels will spin free for 60 sec or so after a good spin. The front drags to a stop in a turn or a turn and a 1/2.

I am thinking of getting the rotors turned to thin them out a little.... they need a turning anyway.

What is the control/governor for how far the piston should retract? Vacuum in the line I would guess, which is a function of fluid capacity. But the reservoir content is variable.... what am I missing here?

[James]

Yes I am wondering about this too. The same thing with mine, the back ones spin so nicely, but the front ones require quite a bit of force to get moving and they stop quickly, though when you feel the discs after driving they are not too hot and one is not any hotter than the other.

[TomO]

Remember that these are front wheel drive and when you spin the front wheels you are spinning the driveshaft and the differential and the trans gears/flywheel/engine if you left it in gear. If the trans is in neutral, you'll only be spinning the components to the diff and other side of the car.

My VX front wheels only spin a turn or two and stop when the car is in neutral and both fronts are off the ground.

[lca13]

Yeah I know, but they spin much free'er without the calipers in place :-)

HELP!... me with my wiring.... I am down to verifying where the 2 O2 signals go to.... pls. see my other threads.

[TomO]

For the 5wire....you can de-pin the 4 wire connector and pin them into the 5 wire connector since you will be re-using the O2 signal, ground and for sure the heater and heater ground. You will more than likely have to run a wire or two from the connector to the ECU for the calibration resistor.

I am emailing you the schematics to show the differences.

[lca13]

Holy moly thank you! Taking a test run now.... no CEL so far.

[lca13]

Runs fine exept when it seems to fall into lean burn, then the injectors seem like they are randomly miss firing.... the car fights to maintain speed... drops slowly, then it seems like the lean burn mode quits and the engine goes back strong..... repeat for 67 miles and also saw a big mpg drop... from solid 50's to 40. hmmmm

[lca13]

hmmmm, looking at the 49 state versus CA schematic... perhaps I am missing something else.... like and EGR valve :-) Still researching.

[TomO]

Missing EGR could cause some issues. I'm kind of surprised that the ECU hasn't thrown a code for the missing EGR lift sensor if you don't have one.

I still think a picture of your engine specifically where the EGR Valve would be would help.

[lca13]

The schematic doesn't show the EGR, but I think it is there.... the Helms does not indicate a lack of EGR on CA VX's... and I think I still know what an EGR looks like, even after all these years :-)

I am gonna verify the EGR to ECU mappings to make dang blang sure and then start monitoring the lean burn voltage differentials to see what that shows.... a too lean mixture to ignite 25% of the time would describe the symptoms exactly. :-)

[lca13]

EGR there in the middle I believe....

[TomO]

Yup, EGR is there. I'll send you the other pages of the diagrams with the EGR wiring in there to help out.

[lca13]

OK, I think I am down to ground issues.

When I had the Heater ground going to chassis ground, things ran real rough at lean burn

I now have the heater ground going to D22, along with the other wire.... Running much better.

But, the volt differentials between D8 D16 D18 are much broader than liste previously so I believe my ground situation still is not right.

The other thing that is interesting is the D22, D3 connections... which basically puts a resistor (in the harness) in between the 2.... that obviously affects that actual potential of the d22 ground with respect to chassis ground....

more playing around and reading... but HELP if anyone can simply solve this for me.... i am real close.

[lca13]

D8 to chassis ground is 5.6 V. About 2x what it should be according to some other posts.

I just called Honda to see if I could purchase a ecu test harness (plugs between the ecu and the existing wires allowing you to inspect each pin while the whole thing is plugged in). He laughed ... before he quoted the price.... $800.

[lca13]

OK I think I have the wires right (heater ground simply had to go to A23).

Now the test voltages appear consistent with all the data in the forums.

So I think it is right but it seems extremely aggressive going into lean burn and the engine then misses.

What is interesting about this is that I have experienced three different lean mode bahaviors depending on changing one wire:

heater G to chassis ground: agressive lean burn and missing but driveable
heater G to D22: milder lean burn, some missing but quite driveable
heater G to A23: very agressive lean burn... not as driveable.

The latter, heater G to A23 is the spec location. With this I get the desired reference voltages listed elsewhere in this forum. But obviously something is still wrong... continue to think grounding obviously. time to recheck the wires for the 11-teenth time and I also plan on doing all the Helms troubleshooting to see if anything stands out there.

[TomO]

I'm pretty sure of this but you have fresh OEM plug wires and the correct NGK spark plugs and correct Gap right?

[lca13]

I did check the plugs... they are correct based on your's and other posts.

Here's the thing... it is all basically working and I have gone through "all" the Helms troubleshooting procedures and all the voltages and resitances are correct.

But, the D14 to D16 voltage.... the stuff that should indicate rich, stoich, lean... is correct when cold (-0.78), then varies like expected during warmup... but under speed down the road it keeps leaning up to 1.2 volts or so..... the engine runs ok about to, say, about 0.9 v... but the higher the worse ir runs.... Also, complete deceleration with no throttle reads 1.45 which I take is the zero fuel case.

Again, it is behaving sort of right and the readouts are. for example, after the rough running at 1.2 v... when the speed slowly drops, it then drops out of lean burn (you can feel it power up) and the voltage readings drop to, say -0.4 to -0.1 or so, indicating now rich.

Tell me about the 5 wire O2 resistor? Mine is reading 7.5K ohms.... how is this used?

Basically it is working but the ECU is just pushing the lean condition too far.

[lca13]

also thinking about why three of the leads are shielded in the harness to engine section.

Tonight on the way home I had a long throttle closed deceleration and the volt reading went as high as 1.9V (almost never higher than 1.5V prior)... and then at the bottom of the hill the CEL came on..... shutdown and restart... no CEL.

So I've got a calibration thing going on. Whether grounding, shielding, or maybe the O2 is also near the end of life... who knows but I sure am having fun. Consumed maybe a better word :-)

[TomO]

The Calibration resistor is jut that, a calibration that the ECU sees to compensate for variances in production of the L1H1.

There was another VX owner that was getting some high/lean readings like yours and found out the O2 was coming to the end of the line. It would suck for you if this was the case since I just sold you that O2 and it did work fine in my car.

I'm glad that you are having fun being the pioneer in the swap to lean burn though.

[TomO]

Oh, hey, forgot to add....Try cleaning your EGR and EGR ports in the intake manifold. There is an EGR cleaning kit for The accords, and I'm going to check if there is one for the Civics as well. I clean mine by taking off the EGR valve and the spraying CARB/Choke cleaner into the ports with the little red straw. The symptoms of clogged ports are stumbling under light load and highway speeds.

[lca13]

>> It would suck for you if this was the case

Too funny.... but if I just hooked it up and it worked, what fun would that be? What amazes me is how anybody has figured this out. For example, each of the interesting O2 sensor connections is referred to by up to 4 different names in the vaious materials I have looked at.

VS+, VS, VNB sense
IP+. Pump current
IP-, VS-, VS/IP, common

At least I will have all this info wirtten down and correlated for other adventurous souls soon :-)

[TomO]

Be sure to check the condition of the 3 grounds for the engine Bay:
The negative cable of the battery to the passenger shock tower
The transmission case to the chassis on the passenger side
The driver's side of the valve cover to the chassis behind the driver's side headlight.

There is an additional ground point on the thermostat housing towards the firewall below the Distributor. This ground point is for the Distributor sensors and Fuel injectors IIRC.

Make sure there are no frayed wires or corrosion on them as well as making sure that they are tight.

[lca13]

Actually I super-enhanced those ground wires a while ago after the local performance parts shop (one of those "big on the web" small store in front places) to me about this.

Get this: I went in there to maybe buy an intake... a header... ready to spend some money and the guy told me to get the Sun ignition ground thing... $100 and nothing else and I would notice a big performance improvement. The web research indicated a lot of positive results as well, so a couple of weeks later I supplimented each of these three grounds with two strands of 10 gauge copper, cleaned all the connections, got a heavier battery to chassis cable... I noticed an immediate responsiveness improvement just like he said I would. More than I would have expected but it was clearly there.

[TomO]

ok good, I just thought of that last night as I was going over my own grounds on my VX and noticed that my trans-to-chassis ground is frayed and corroded. Since today is my last Duty Day for the school year, I can start working on my intermediate wiper How-to for the site along with rebuilding my spare VX motor, a brake job on the VX, and the re-grounding of the chassis. I also have two spots of rust left to repair and then my VX will be "factory fresh".

[lca13]

Rust... ah, I remember.... don't miss that though.

Do you happen to know how varying the calibration resistor would affect O2 operation? I cut it and put a 10K pot in the middle and things seem a little better at 10K than the default, which was 5.7K ohms. Gonna run and get a 20K and see what that does.... just playing around cause I can't seem to find a description of exactly what the resistor does, other than "calibrating" the O2.

[lca13]

Finding that a higher resistance value seems to lessen the lean burn agressiveness. Tonight driving home I varied the calibration resistance up to 60K ohms (default is 5.7k).... it was still missing slightly in lean burn.... but not very bad at all, at speed anyway. The voltage across D14,D18 was not as high.

also put in a brand new set of plugs tonight in the parts store parking lot... no noticeable positive change with them though.

Gonna get a 100K pot in the morning and try that.

[TomO]

hmm, I've never thought of changing the Calibration resistor. You're sailing uncharted waters at this point Lance. The only thing that I can think of is that th4e calibration resistor is part of the circuit for sending the O2 signal to the ECU, so in effect, you are altering the O2 signal that the ECU sees. But don't take my word for it as I haven't looked at the actual OEM controller circuit for the L1H1 in the P07 ECU, only the Ozzie controller circuit for the L1H1 which is different from the Honda one.

[bluebird]

how much of a difference in mpg between CA models and 49 state? Im getting like 48mpg with my CA VX... 215k miles , hx wheels....

[lca13]

EPA est was 5 mpg greater in the 49 state... if I recall correctly it was 51 city 55 HWY ?.. something like that.

I am cosistently getting in the low 50's with a couple 54's and one 58.... before lean burn (which I am taking a break from for a bit)

[lca13]

OK, might have got this lean burn thing working... I tried a different O2 sensor and all of the voltages now seem consistant with what others have seen. I am also monitoring injector pulse rate and it seems like it is injecting about 10-15% less fuel at cruise now compared to the non-lean burn ECU (just antecdotal observation though).... I might have to fill up and make a MPG run after the US Open finishes :-)

[TomO]

Congrats Lance....Make sure to do a How-To to share with the world.

[lca13]

Yeah, I'll do a DIY after some of the MPG runs are in... just the info on which three 4-wire O2 sensor wires and which 4 harness wires to patch into will help others.

[lca13]

Lean burn is clearly working. I have a DMM hooked up to injector 1 measuring duty cycle. you can see (and feel) when it drops into lean burn.

Last tank was 62 mpg..... with A/C on for at least 1/2 of it and 10-15% city.

[TomO]

nice, and congrats! now get to that how-to, lol!

[lca13]

Best tank ever: 68 mpg.... 325 miles over one week's commute. Some A/C on even. Couldn't have done it w/o the Super Mid though.

[garyhgaryh]

Best tank ever: 68 mpg.... 325 miles over one week's commute. Some A/C on even. Couldn't have done it w/o the Super Mid though.

You went from avg 50mpg to 68mpg?!?!
Do you have the shift light hooked up?
Thanks,
Gary

[lca13]

hey, been offline for a bit. No shift light but have driven one with a light. basically tells you to shift as soon as possible.... like 1600 rpms

[smccall]

lca13, please post a DIY on this process. I'm looking at a VX and just found out that its a CA FED VX. So far I know you need a non CA FED ECU and a 5 wire O2 sensor. Is this correct? TomO, please chime in if I'm missing something or if you have a write up on this.

[TomO]

Fed emissions ECU, 5 wire O2, and a socket for the 5 wire O2 are what you need for parts. LCA is the person to look towards for the wiring though. There is a post by him in a thread somewhere around here on the wire details though. Try searching "O2 conversion".

[smccall]

Thanks TomO

[mango]

lca13, congrats on getting that conversion squared away! Is there any chance that you could share all that precious info that you've compiled? I'd like to convert my CA VX.

[garyhgaryh]

Mango, where do you live? I bought a fed vx ecu a few months back. I haven't done the conversion yet, but am planning on doing it this year. If you live in the bay area (CA), we could get together and work on the conversion. I'm in need of a connector and the o2 sensor.

[Hondork]

I live in Oakland and would be interested in this mod (I, too, have CA VX). I'm just getting it back on the road after doing some major bodywork.

On another note...
Earlier in this thread there was some talk about front brakes being stiffer than rear brakes. I know most of you already know this but:

The shoes in your drum brakes only engage the drum surface when you depress the brake pedal. Then springs pull them back away. This is nice because there is no friction when it isn't wanted but the downside is that after a while the shoes wear down and they don't engage the drums as much. Yes, there are mechanisms in place that supposedly self-adjust but none of them really work great.

The pads on your disc brakes are always in contact with your rotor. They don't retract when you take your foot off the brake, they just stop squeezing. The calipers do not have any mechanism for retracting, that is why you have to force the piston back when you put new pads on. Disc brakes always have some amount of friction (beyond the fact that our front brakes are tied to the tranny/engine as TomO pointed out).

So what we gassavers really want are drum brakes all around. Unfortunately there isn't a reasonable swap for this. I don't know of any front wheel drive cars with drums up front, they just don't work as well. Maybe Honda or Toyota will come up with a "no braking/no friction" disc brake set up one of these days.

[R.I.D.E.]

In recent years they have designed the caliper seals to provide some retracting force on the pads so the drag is reduced. Absolutely have the rotors turned to minimize drag. I have seen replacement rotors that were warped 20 thou. We turned them whether they were new or reused.

regards
Gary

[Hondork]

Really? That's great. I wonder if there are any that we could retrofit to our brakes.

[suspendedhatch]

The pads on your disc brakes are always in contact with your rotor. They don't retract when you take your foot off the brake, they just stop squeezing. The calipers do not have any mechanism for retracting, that is why you have to force the piston back when you put new pads on. Disc brakes always have some amount of friction (beyond the fact that our front brakes are tied to the tranny/engine as TomO pointed out).

So what we gassavers really want are drum brakes all around. Unfortunately there isn't a reasonable swap for this. I don't know of any front wheel drive cars with drums up front, they just don't work as well. Maybe Honda or Toyota will come up with a "no braking/no friction" disc brake set up one of these days.

If you're looking for front drum brakes you can get the old Beetle. It's not FWD but it's Rear engine so you don't have the drivetrain losses like you do with RWD or AWD.

Drum brakes up front is really unsafe. Drum brakes suck, they only persist because they're cheaper to manufacture. But they can fill up with water. They easily overheat. They're overly complicated. Nobody here wants to trade safety for mileage.

Disc brake rotors supposedly "beat back" the pads. But yes it is true that they drag some especially on older calipers. Honda doesn't make the best brakes in the world, but they're also not the worst.

I'm pretty sure the OP could have saved some grief if he had found a "B18C into a VX" swap guide and worked backward. They convert the 5 wire O2 to 4 wire.

There is nothing to fear from "15 year old wiring". The wiring itself should be as good as it was when new. Sure, the tape is dry and cracked in places...

[mango]

Nobody here wants to trade safety for mileage.

Hey, I drive a Metro! :D


Sorry I couldn't resist....

[mango]

Mango, where do you live? I bought a fed vx ecu a few months back. I haven't done the conversion yet, but am planning on doing it this year. If you live in the bay area (CA), we could get together and work on the conversion. I'm in need of a connector and the o2 sensor.

gary, that is very nice of you to ask. I would definitely like to be part of a swap so I can get more info on doing my own! Unfortunately, I live in San Diego. Thanks again and best of luck! Please post back with how it went after alls said and done.

[garyhgaryh]

Wow, I haven't been back in a while and there are a handful of replies. Hey guys, can you take a picture of your new O2 connectors?
Gary

[SCoupe]

I wanted to post my extrodinarily easy and positive experience converting a 1992 Civic VX California emissions to a 49 state Federal lean burn version.

As posted elsewhere, many (all?) 1992 CA Civic VX's came with the 5 wire o2 sensor installed and that included mine, so nothing to do there. The only thing I had to do was to unplug the exisiting CA ecu and replaced it with a used 49 state ecu that I purchased.

Done, perfect, immediately have a fed version lean burn mode Civic VX. This will go down as one of the easiest modifications with a big impact that I have ever done.

Just so you guys now that this swap out can be stunningly easy to accomplish given certain senarios.