Root16

I have a 1993 Civic VX which I purchased for fuel economy. It has some idle issues which have proven very difficult to fix. The car is a bit of a beater. It has 177,000+ miles. I don't know the exact miles since the odo/speedo only work about 60% of the time!

When the car is warmed up, the idle roams or surges from about 700 or 800rpm to 1200rpm--sometimes the range is less, but that's about what the range is. Every so often it will stop roaming and sit at 1000 or 1100. It's a VX so it's supposed to idle at 500RPM.

The other issue is the idle sticks.... It has a hard time coming down when you put the clutch to shift. So you accelerate to 3000RPM put the clutch in and the rpm keeps going up a little - hangs out for a few seconds - then starts to come down slowly until it gets back down to 1000.

any help is GREATLY APPRECIATED!!
thanks
Jason

philosofy1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Root16 &raquo;</TD></TR><TR><TD CLASS="quote">I have a 1993 Civic VX which I purchased for fuel economy. It has some idle issues which have proven very difficult to fix. The car is a bit of a beater. It has 177,000+ miles. I don't know the exact miles since the odo/speedo only work about 60% of the time!

When the car is warmed up, the idle roams or surges from about 700 or 800rpm to 1200rpm--sometimes the range is less, but that's about what the range is. Every so often it will stop roaming and sit at 1000 or 1100. It's a VX so it's supposed to idle at 500RPM.

The other issue is the idle sticks.... It has a hard time coming down when you put the clutch to shift. So you accelerate to 3000RPM put the clutch in and the rpm keeps going up a little - hangs out for a few seconds - then starts to come down slowly until it gets back down to 1000.

any help is GREATLY APPRECIATED!!
thanks
Jason</TD></TR></TABLE>

grab a rag and soak it down with some brake cleaner. then wipe down the inside of the throttle body and the butterfly (have to remove intake runner first).

as for the surging idle, try replacing the pcv valve. the one thing many over look, but will cause this problem when they are clogged. they usually run about $3.

Root16

The mechanic doesn't think it's a vacuum leak based on the work he's done so far in trying to fix it. I was told my throttle body had been tampered with and was suggested that might fix the problem. I read on here to clean the throttle body plate but haven't done that. As well as replacing the throttle cable which I haven't done. I have had the IACV cleaned. Any other ideas? Should I get the throttle body plate cleaned and replace the throttle body cable even if it looks okay?

Yes, I did replace the PCV valve as well. No dice.

I will run that by the mechanic tho, thanks.

Also, could it be the FITV needs to be cleaned?


Modified by Root16 at 3:01 PM 10/1/2007

philosofy1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Root16 &raquo;</TD></TR><TR><TD CLASS="quote">The mechanic doesn't think it's a vacuum leak based on the work he's done so far in trying to fix it. I was told my throttle body had been tampered with and was suggested that might fix the problem. I read on here to clean the throttle body plate but haven't done that. As well as replacing the throttle cable which I haven't done. I have had the IACV cleaned. Any other ideas? Should I get the throttle body plate cleaned and replace the throttle body cable even if it looks okay?

Yes, I did replace the PCV valve as well. No dice.

I will run that by the mechanic tho, thanks.

Also, could it be the FITV needs to be cleaned?</TD></TR></TABLE>

if the throttle body was tampered with, that might be the problem. if it was tampered with bad enough, the tp sensor might need to be recalibrated. that is something your mechanic could do.

Root16

mechanic finally found the problem after a lot of diddling with his computers. He cleaned the throttle body and the car is *almost* as it should be. The sticking idle is fixed. Yay! But the idle is still high. It doesn't roam anymore, but it sorta bounces a little. So you drop it into neutral to coast to the stop sign and the idle drops below 1000 but instead of resting at the 500rpm place it's supposed to it then bobs up to about 1100. Any ideas? He thinks the ECU has a problem because when he hooked up his $7000 computer to it, on his computer the readout was 0 for the RPM instead of showing the RPM readout of the car.

95teilhatch

i had the same problem wit hmy eg. i took the fast idle control valve out and cleaned it a reinstalled it and it helped the problem out greatly. the FICV is on the bottom of the TB. there are how to write ups on here telling how to take it out but its a pretty simple 3 or 4 bolt job. it took me 30 minutes to do the whole job. just clean that out b4 you go messing with the ECU.

Root16

Thansk Donkey, I will ask my mechanic if he cleaned it. Also, the power lag came back after he returend the car to me! I had finally gotten rid of it. Spark plugs were main thing that improved the problem. But I think a valve adjustment also helped. Any idea what he might have done to cause the power lag/surge problem to return? He said the idle should improve once the stuff he sprayed in the TB to clean it has burned off. It's been about 120 miles since I got the car back from the mechanic. He also said I should come back in a couple days for an adjustment-- "it'll need an adjustment- I expect that" not sure what he was referring to... but an adjustment does seem to be in order!

Thanks guys for helping out.

1988_96hb

my roommate has been telling me my 92 vx has been having these problems (idk as i was resently released from my month long hospital visit) looks like i have work to do. lol

Root16

very common problem with the vx. My mechanic told me today that the problem only happens at low rpms so don't drive at low rpms. he's right, but that's where the 60mpg is realized.