New member with '93 Civic VX

[bluesteel93]

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

[vikisangre]

congrats for your VX

[GotToyota]

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.

[92civicvx]

Originally Posted by GotToyota

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

[tvbd56]

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

[GotToyota]

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?

[92civicvx]

Originally Posted by GotToyota

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.

[GotToyota]

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.

[ChewChewTrain]

Originally Posted by GotToyota

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.

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

[imawakenow]

Originally Posted by ChewChewTrain

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.

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...