problems with lean burn in my civic vx - Fuel Economy, Hypermiling, EcoModding News and Forum

bryn · 12-05-2010, 02:29 PM

i just bought a 92 civic vx a week ago, working out the kinks.

it feels like when it should be going into lean burn, warmed up, at cruising speed, light throttle, it stumbles or misses as if it was running out of gas. if i give it just a little more throttle say from 20% up to 25% runs fine again.

also if i am driving down a hill in gear, where i think it should cut fuel to the injectors the check engine light comes on until the car is turned off again.

any vx owners had either of these problems? or know how to check the check engine light code?

thanks much for any ideas

tim3058 · 12-05-2010, 02:45 PM

My lean-burn issues seemed to be traced back to faulty (re-)wiring by the previous owner, although the code said O2, along with a few others. You can use a wire to jumper across the 2 prongs in the green terminal hanging under dash by the pass. door to see what the codes are.
Check your connections under the hood along the right pass. fender. Maybe plug & unplug each one a few times to clean up terminals. Then check the wires leading to the ECU by the pass. door pillar (under the dash) for any ghetto re-wiring.

bryn · 12-05-2010, 03:18 PM

thanks i will check out the wiring before i start spending money.

Ryland · 12-05-2010, 06:12 PM

I got a great deal on my civic vx for the same issues and I bought it because I was 99% sure that it was the o2 sensor, replaced the o2 sensor and it runs perfectly.
The o2 sensor does not always trips the check engine light when it is first wearing out but it sounds like yours is pretty far gone.
It will be a bit pricy but if you search around you can find them for $100 or so, otherwise auto part stores sell them for $300.

MetroMPG · 12-05-2010, 08:57 PM

And congrats on finding a VX, bryn. Envious.

93_VX_Guy · 03-10-2011, 07:17 PM

Did you figure out what the problem was? I'm having the same issue. Unfortunately for me it's not the 02...

Ryland · 03-10-2011, 07:36 PM

Quote:

Originally Posted by 93_VX_Guy

Did you figure out what the problem was? I'm having the same issue. Unfortunately for me it's not the 02...

It could also be the throttle position sensor on the throttle body.

93_VX_Guy · 03-14-2011, 07:16 PM

Quote:

Originally Posted by Ryland

It could also be the throttle position sensor on the throttle body.

It's not the TPS, MAP or the EGR, car has new NGK plugs, OEM cap/rotor, plug wires, fuel filter... Strangely the problem goes away when i unplug the 02 but it's a brand new NTK L1H1 sensor.

I've cleaned the EGR ports and valve, seafoamed the engine...