Hey guys,

A friend of mine has a 92 Civic. He swapped the original motor for some knock-off japanese 1.5 litre v-tech. Don't ask me the specs, I have NO idea.

On start up the REVS are extremely high, around 3000, then after a couple mintues of warm-up, it starts reving wildly, from 2-3 grand like someone were tapping on the pedal.
I checked the throttle position on the motor, no issues there....as far as I can tell, it appears to be related to the throttle or something.

I have NO clue when it comes to imports, my expertise is in the North American Forced Induction (supercharged) area...you guys may burn me for this.....

I'm an Owner of a Modded 2001 Ford Lightning, 440 rwhp/520 ft lbs.

Here's my sweetheart..

 

Clean or replace the IACV

Check for vacuum leaks

 

Definitely check for vacuum leaks. Can you kill the engine by completely covering the top of the throttle body (air cleaner removed)? If not, there's a massive intake air or vacuum leak. Check all the vacuum hoses and connections. If no luck, the IM or throttle body gasket may be leaking.

Another place to look is the FITV. Try cleaning it.

 

dont overlook the idle screw on the TB to see if it is adjusted all the way open. also for the fluctuating idle the tps or map sensors could be switched causing the idle to rev and drop.

 

From reading up on this for a brief time, it looks like this is somewhat of a common issue?

 

On another topic, tranny uses Mercon/Dexron 3?

 

honda MTF. get it from the dealership

 

Wasn't sure,buddy was headed out tonight and before he took off realized he had no Tranny fluid, ended up filling with my leftover Mercon.

 

 

My vote is for IACV or FITV as well. The idle screw will not cause it to fluctuate and neither will the MAP and TPS being switched. If they were switched it would shut off.

 

Also, if none of this ^^^ stuff works, get a leak down test to check for internal vacuum leaks. Nice druck, i like the eyebrow.

 

I will wrench away on the things mentioned, I do all my own work on my truck, tools and hands-on issues are not a problem.

Thanks, but what do you mean by eyebrow? headlights you mean?
they're stock, SVTmade for the lightnings only,more aggressive look than reg. f150s

 

He has a slushbox. I did a quick search and it looks like Dexron II was right, but Dexron III will make it shift hard. When in doubt, use OEM. If he's losing fluid, check the axle seals on the tranny.

 

if its idling that high it must be a big *** vaccum leak! like the one that connects to the brake booser? the IACV wont cause it to rev to 3 grand. theirs a mean vaccum leak and is causing it to rev up and down.

tell ur buddy to check all the vaccum hoses on the intake manfold or the idle adjust screw. Good luck. And nice Lightening. I'm a Ford guy im into Cobras and Probes myself. and love forced induction. but the cobras are my dream cars!

 

i have had the same problem for my 1998 honda civic dx running a d16y7.. my idle was going from 3grand to 5 grand fluctuating.. up and down.. i replaced the IACV (idle air control valve) and it fixed my problem.. i just went to the scrap yard picked one up for just 20 bucks and it was purring like a cat..