Civic-EG.com Forum 3.3.1

- Sat Aug 23, 2008 4:46 am #67094 Car: 1993 Honda Civic VX
86K miles. Original and stock on everything.
On my trip to Buffalo from Boston, I got 54MPG with ac on low the entire ride. Going back to Boston, no AC on and only got 56MPG. Something is not right.

After driving back from Buffalo last night, I noticed during hill climbing, my car takes a while to get out of lean burn. It usually gets out at 1-3 seconds but while the pedal is still depressed it won't accelerate at all. I had to release the pedal and applied it again. This was doing 65MPH going uphill accelerating on 5th.

Earlier while driving my car, I also noticed the RPM drop to 0 every times I press the clutch in. And when accelerating, the rpm seems laggy. SIL goes on at 1000-1600rpm 1-4 gears. Don't know if this was the reason affecting my mileage last night but I'm hoping to get it fix. Also during idle, the needle will be resting at 0.

Any answer to this problem?

Also for cleaning the IACV, do I need to watch out for any liquid, etc? Trying to find the problem before Sunday.

1993 Honda Civic VX
84K original miles
All Stock!

- Sat Aug 23, 2008 7:43 am #67098 you problem sounds severe.. i would first check your tps sensor for your idle but it sounds like a map sensor problem. *strangely though, my civic vx's idle was surging..... the only thing i did to fix it was buy a 3$ can of throttle body cleaner and wala! everything was fixed.*

So it wouldnt hurt to clean out your throttle body, but just get a lil dvom of some sort and check out your tps and map sensor..... thats what i say.... OR.... you might have a vacuum leak.... that would suck.... you know what.... check to see if you have a vacuum leak anywhere. My civic vx had a vacum leak.... the idle was all jacked and set off the check engine light.... yeah i think its a vacuume leak O.o....

[suspendedHatch]

- Sat Aug 23, 2008 3:42 pm #67108 56mpg freeway is pretty good for a VX. That being said, it doesn't mean you don't have a problem.

Tach/speedo problem is indicative of a bad or failing VSS or cluster.

If you have a CEL you need to retrieve the code and go from there.

- Sat Aug 23, 2008 4:43 pm #67117 No CEL. I just had my dad friend to adjust the throttle at wire or something. After pressing in the clutch, it dip down to 0 and bounce back up to 700. Any other suggestions?

1993 Honda Civic VX
84K original miles
All Stock!

- Sat Aug 23, 2008 6:28 pm #67125 Also, when coasting in neutral and braking, the rpm needle moves between 0-800 repeatedly.

1993 Honda Civic VX
84K original miles
All Stock!

[suspendedHatch]

- Sun Aug 24, 2008 3:36 pm #67171 Now you will have to put the throttle cable back within spec. You do not adjust the idle that way on a Honda. That is old school domestic idle adjustment. Doing this on a Honda throws off the TPS calibration. Instead you adjust the idle adjustment screw, but that is not your problem.

The repair manual has the idle adjustment procedure in it. Basically you want the car to idle at 450 when the IACV is unplugged. Then you want to reset the ECU.

There are numerous idle threads on this forum and on others. There's a pretty big one over at Honda-Tech. It's a very common problem. It can be caused by bubbles in the coolant, a vacuum leak (cracked vacuum hose), a bad gasket on the throttle body or intake manifold (unlikely if you've never removed either), a dirty/clogged IACV, a dirty throttle body, a FITV that's gone bad or needs adjustment, ignition timing out of spec, etc.