New member with '93 Civic VX
 

Hello friends,

I just recently picked up a 1993 Honda Civic VX. It currently has 191k miles, pretty good shape all around. The previous owner did some things I'm not fond of, which consists of:

- DX exhaust manifold
- 2.5" exhaust piping after the catalytic converter to a loud Greddy muffler
- Aftermarket intake
- DX transmission (much shorter final drive ratio)

I am currently working to get it back to stock-like condition. Here's what I've replaced so far:

- Throttle body gasket
- Map sensor o-ring gasket
- Removed EGR valve and cleaned, installed new gasket
- Stock VX exhaust manifold
- New OE-style catalytic converter
- OE-replacement exhaust from catalytic converter and back
- Fuel filter
- New cap/rotor
- New NGK spark plugs (the ones recommended by Honda)
- Timing adjusted and set to 16*

Still looking to do a few things. Mainly finding a stock intake to replace the aftermarket ricer one in here currently (if anyone has one for sale, let me know). I look forward to getting some great mileage and reliability out of this. First tank yielded me 37 MPG average before the tune up, second tank in showed 39 MPG. Slowly getting higher as I get it back to where it needs to be. Hoping to average mid-40's, I'd be happy with that.

Transmission is being replaced with a newer HX transmission this weekend, not a VX but way closer in final drive gear ratio than the DX one in there currently.

Welcome! Glad you're turning the vx back stock. It'll be hard finding stock parts, hopefully you can find what you need

Thanks! Indeed I have been searching for an air tube since I bought the car a month ago and it has been useless so far. Honda discontinued the airtube itself otherwise I'd just buy it brand new.

This has been a little frustrating.

Just went to the local dealer to get some Honda MTF for the upcoming transmission swap on Sunday and asked about the air tube for kicks. It's been discontinued for awhile and there are 0 available nationally. Bummer. :(

Welcome to the site and congrats on the mostly VX. :) I'm sure you'll be pleased once you get it closer to stock and start doing some ecomods. The VX guys are really getting some ridiculous numbers.

There has to be many of these vehicles in salvage yards, where you can pull parts yourself.

Welcome to the site, the more VX's the better haha. Ill keep an eye out for hatches at the yard I go to. Worst case you turn that ram air intake into a hot air intake. i would try car-part.com for OEM pieces. Sucks that they switched the trans out on you. Lets see some pics!

I will check the yard here soon when I have time too, but I tried car-part.com with no luck, only DX intake tubes.

I was debating going the custom intake route but I would much rather just go back to stock if at all possible.

Few pics:

http://i5.photobucket.com/albums/y18...ic%20Hatch.jpg

http://i5.photobucket.com/albums/y18...807907_HDR.jpg

Second picture was before the exhaust change. It's been lowered with Koni Yellow struts and Megan Racing springs, not my first choice but it rides nicely and I like the adjustability of the Yellows.

The previous owner also converted to SI rear disc brakes, Integra front brakes (reason for bigger HX wheels) and Integra front strut bar.

Just bought a stock intake tube for $30 shipped. Score!

Cool. Nice persistence. Good luck with the transmission swap. The shifter linkage is a PITA. I saw one guy online keep the linkage connected until after the trnas was removed (better leverage for the so-called b*tch pin removal/install.

Great looking VX.

Thank you!

Luckily I'm paying my mechanic friend to swap it who has done it many times.

Also getting a new drivers side axle and replacing the slave cylinder, throwout bearing and pilot bearing while I'm in there. The clutch disc was done not too long ago.

Great looking VX. I hope you have as much fun and MPGs as we have with yours.:thumbup:

When I did mine, I left some hardware in place. I replaced the throwout bearing, but I did not replace the clutch, flywheel, or slave cylinder. All was 1998 OEM stuff, never replaced. Two-and-a-half years later the clutch is still fine (230,000 miles now). But the slave cylinder went out probably a year later, maybe less.

You never know with this stuff.

But so far, I have followed the principle of not replacing things that have not failed. I will say though that I do not look forward to one day going back into the transmission job to replace flywheel or clutch, when I was already in there... we'll see... maybe my luck holds out? :thumbup:

About two hours ago I acquired a stock airbox, including the resonator that goes under the bumper towards the passenger fender liner. Looking forward to getting it all put in.

Anyone have any preferences on filters? I'm wondering if a K&N would improve my mileage.

Question: So since I bought the car I have had issues with the idle occasionally dipping and sometimes stalling. The idle doesn't bounce, and I've replaced the throttle body gasket, map sensor o-ring, all the vacuum hoses except the lower PCV hose, PCV valve, upper PCV valve hose, distributor cap/rotor, spark plugs and adjusted the idle according to the service manual.

Is it possible that the lower PCV hose is the culprit? It's the only hose I haven't replaced. I did replace the PCV grommet that is at the breather chamber as well but the PCV valve that goes there is questionable, I wonder if I should replace it also?

Doesn't show the part on here but I'm wondering if #2 is the same as the upper PCV valve (#6 in the diagram, part number 17130-PM6-003).

Honda Automotive Parts

Spray some brake cleaner down on that hose and if the idle jumps vacuum leak, how are the condition of your plug wires?

The plug wires are NGK's that came with the car, but honestly I can't confirm how old they are. Cheap enough to replace but if I could avoid spending an unnecessary $45 it would be nice.

Because the previous owner put those HX rims on there, I would look into getting RE92'S for tires. Will probably pick up 3 to 4 mpg at least, and the car will be a little snappier.

separate thread?
 

I would recommend posting this question as a new thread in the off-topic tech sub-forum. Might get better response there. Personally, I am inexperienced with the PCV. But we have some civic owners with lots of experience who might not notice this question in a thread with this title. Hope that helps.

Thats good to know. Who produces those?

I never thought I would be happy to go back to stock.

Stock intake pipe and new K&N filter
http://i5.photobucket.com/albums/y18...20intake/1.jpg

For those curious, DX vs VX intake pipe
http://i5.photobucket.com/albums/y18...20intake/2.jpg

Inlet size difference
http://i5.photobucket.com/albums/y18...20intake/3.jpg

Ricer intake
http://i5.photobucket.com/albums/y18...20intake/4.jpg

K&N installed
http://i5.photobucket.com/albums/y18...20intake/5.jpg

Back to stock goodness
http://i5.photobucket.com/albums/y18...20intake/6.jpg

Wow. The airbox and intake tube design on the next gen DX was quite different.

Took it for a drive this morning, idle seemed off, it would reach about 800 or so then work its way back down to 550, but not sporadically, very smoothly. Went through the steps from scratch to re-adjust the idle, also removed the throttle screw from the body out of curiosity and cleaned up the mounting hole and the screw/plug itself. Drives fine, but for some reason I feel there is an intermittent misfire. The plug wires are the only thing I haven't replaced so I may do that here soon. I noticed there are different part numbers between the VX and DX wires so there is some kind of difference there, I wonder if someone put DX wires on here and if that could cause any issues. However, I will say that it seems the stock intake gave back a bit of low end torque that I felt was missing from the huge intake that was on there previously.

Next on the list is a new OE heatshield for the exhaust manifold.

Anyways, caught a better picture of the engine bay during the daytime and a random pic of the car itself.

http://i5.photobucket.com/albums/y18..._112827532.jpg

http://i5.photobucket.com/albums/y18..._121245481.jpg

Reposting this from a tech thread I made in the OT section just to keep consistency with my ongoing maintenance/diagnostic stuff.

http://ecomodder.com/forum/showthrea...oid-32384.html

So after some reading, and quite obviously, this solenoid valve is a part of the evap/emissions system with the charcoal canister. Some have stated that without this valve the car could potentially run rich or develop a smell of fuel. Removing it will also negatively affect gas mileage.

Like I mentioned before, the previous owner removed the one on this car for whatever reason, as well as the other charcoal canister lines.

Before, nothing there but the screw, vacuum line hanging below, plug freely hanging (looks identical to IACV connector but different colored wires).
http://i5.photobucket.com/albums/y18...ake/Before.jpg

The valve, which for test purposes, I picked up at Pick-N-Pull for $5. I figured it would be worth the few dollars compared to the $130 price Honda wants for a new one. Also not even sure if it matters, but the top "dome" looking piece is a filter that clips into the valve, it's replaceable and costs $9 from Honda.
http://i5.photobucket.com/albums/y18...take/Valve.jpg

Installed with connector back in and correct vacuum hoses, the top nipple connects to the top port of the charcoal canister, the bottom nipple connects right below to the intake manifold.
http://i5.photobucket.com/albums/y18...take/After.jpg

Followed the diagram here for the vacuum lines:
http://i5.photobucket.com/albums/y18...%20diagram.jpg

http://i5.photobucket.com/albums/y18...iagram%202.jpg

I am a little disappointed that this did not get rid of my occasional idle issue where it will drop drastically low or sometimes stall. My idle is not sporadic, so I figure it is something small but I have determined there are no vacuum leaks. Will be replacing the map sensor here soon to see if that helps.

I will say though, that the car feels a little smoother at idle. Will it improve my fuel economy? We'll see come the next few tanks.

Didnt think i read this anywhere on the thread but how new is your o2 and is it the updated correct 5 wire one? I bought a new one and it made a hell of difference. also a valve adjustment helped but not as much as the new o2.

It is a newer 5-wire put in not too long ago by the previous owner and I confirmed it was the "correct" one based on the number that's stamped on it.

welcome
 

Belated welcome to the forum!

Lowered VX with HX wheels - I haven't actually seen that before. Looks great!

And low = good for MPG. HX wheels are also good if you have some good LRR 14's on there.

Congrats on getting a VX! That car looks really clean! Good luck on your idle issue. I know mine stays pretty high on initial start up and then mellows out after its warmed up a bit. Also when I disconnect the battery for awhile and reconnect it it seems to take the Ecu some time to relearn everything and smooth out the idle.

Metro, is this sarcasm? I actually can't tell... Lol.

OK, second VX with HX wheels. :D

(Not kidding about liking the look though.)

Actually 3rd if you count The Donkey CRX's brothers white VX... funny how its all the white VX's with HX wheels though...

congrats for your VX

Just wrapped up my 4th tank of gas and finally broke 40 MPG. Here's what I've done so far:

- New distributor cap, rotor, correct NGK plugs
- Oil change
- Lowered 2" (by previous owner)
- Converted back to stock intake with K&N filter
- New OEM-replacement exhaust from manifold back, installed correct VX manifold, previous owner installed a DX manifold and 2.5" piping
- Cleaned throttle body and plate
- Replaced all vacuum hoses
- New MAP sensor
- Set timing to 12* (or the red line on pulley)
- Idle adjusted per service manual
- Tires inflated to 36 PSI

Any other suggestions? to help my mileage? I think this next tank will get mid-40's since last tank I still had the cold air intake on there for a part of it as well as the old MAP sensor. We'll see how it goes.

MOAR TIRE PSI, like 50-55

I don't know if you've already done it but removing extra weight will help. Even little things here and there

So after doing a ton of reading today, I think I realized that I may have two PCV valves.

The previous owner put in a new "PCV valve" up top at the intake manifold, and I've been reading that normally this is just a black elbow that is a straight flow 90" piece and that the "actual" PCV valve is at the chamber box underneath the intake manifold.

I noticed his PCV valve replacement for the top one was a typical aftermarket replacement, and that the one at the chamber box appears to be original. I plan on ordering a genuine Honda one for the chamber box and fabbing up my own "straight flow" piece up top. Until then, does having two PCV valves (and one possible bad one) seem like a reason my idle will occasionally dip?

I found the same thing on my vx. Put a oem replacement at the breather box(mine was bad) and cut open the aftermarket elbow to remove the guts and reinstalled it. I didn't have a idle issue before this and I didn't feel any difference after. It's very possible it could be causing your issue if both aren't working properly.

Put in a new PCV at the breather box, removed the old PCV hose at the intake manifold and installed one long, new hose. Also ran a full can of Amsoil Power Foam through the throttle body and part of a can through the EGR port. Seems to be smoother to drive, but still not sure if the idle issue is fixed. I honestly haven't driven it enough yet to confirm. I did notice that I seemed to have had a pretty bad exhaust leak between the manifold and the cat, re-tightened the nuts but I may run some more Power Foam through it to see if I'm getting any smoke leaks there still. I wonder if the Power Foam fouls oxygen sensors? I didn't have a bad one to put in in place of the good one so I just ran it, then removed it afterwards and cleaned it with electrical cleaner to get the carbon off.

Also I flushed my brakes, the fluid was a dark green, almost swampy looking. It was definitely long overdue for new fluid.

What IQ score would it take to want to turn a VX, designed specifically for high mileage, into a performance car? (shakes head)

Lots of kids do this because of how light the VX is. Some folks are tricking out first-gen Insights for the same reason. And most CRX HFs I see have been engine-swapped.

GotToyota, nice job on the de-ricing. I hate those cheesy aftermarket intake tubes with a passion. Nothing wrong with a set of Koni shocks, though. :D

Apart from the increased tire PSI, I wonder if an injector cleaning would bring up your MPGs (and smooth out the idle). I've done just about everything you mentioned to my de-riced VX and have been able to surpass 50 mpg on the highway. That's with the VX gearbox and 13" wheels, though.

The RE92s are LRR tires made by Bridgestone, BTW. I wonder how HX wheels with those tires affect mpg compared to the stock VX alloys with 175-width tires...