sleepers91hb

I know this topic has been gone over a million times and I have read them all!

This is my symptoms: My car after warming up idles very low around 100-0 rpm bottoms out. Also, My IACV is always sucking air even when the car is fully warm which causes a constant humming sound. Pretty annoying! If I cover the whole to the iacv the car stalls.

Which correct me if I'm wrong most people have a too high idle caused by vacuum leak or dirty fitv or iacv... So I am thinking that my intake is not getting enough air, that's why the iacv is always open...

When I try to raise the idle to 500-600 the car starts to surge... When I unplug my iacv to set idle, and if i rev the engine just a little the car really sputters figure that has to be a issue of some sort.

Heres what I have done

-new complete dizzy td-44u
-new spark plugs
-new pcv
-new throttle body gasket
-new tps set to .50 at ct wot is around 4.3 could get it to 4.5
-cleaned iacv no difference so I Replaced IACV new oem
-cleaned fitv no difference so I Replaced FITV new oem
-new oem honda O2 sensor $250.....
-new rywire obd0-obd1 ecu jumper and subharness
-I have no bleeder valve for coolant but bled coolant like 10 times with coolant bleeder funnel kit...

This is what I have...
1989 civic si hatch w/ obd0 b16 converted to obd1
usdm p30 ecu
usdm p30 del sol intake manifold
del sol jdm sir throttle body
brand new obd1 dizzy


Any help would be great.... Like I said this has been posted a million times but none had my issue with the low idle after all new parts!

sleepers91hb

Anyone??? Could use some help. I did notice that when I unplug my etc sensor I think it's called my idle seems to raise to the proper idle. But plug it back in again and it drops way down. Could it be a bad sensor.

sleepers91hb

Really no help! Bump bump bump!

tyvtec23

check your intake gasket and wiring, ive had a similar problem and it was my intake gasket and try running a different ecu get back to me

sleepers91hb

I checked my throttle body gasket, cleaned the throttle body noticed my idle screw had a lot of build up thought it could be the culprit but did nothing! I also noticed some of my wiring had been worn out and bare wire exposed on the etc sensor i think its called so replace plug and wire, nothing....

Haven't been able to check intake gasket, tried spaying with carb cleaner but no results. Is there another way to check??

This is my problem i think.... My Iavc never closes, even when car is fully warm you can here the iavc sucking air. If I unplug it it still is sucking air, if I plug hole in throttle body car stalls....

What tells the iavc to close besides the ECU cause i swapped the ecu out too and no changed???

Car runs good, just has a surging idle at stop and I cant adjust idle to proper spec, which makes the timing hard to get right as well.

sleepers91hb

Spelt IACV wrong....above

wanabebuff

I know you have probably done this, but when you took the fitv off to clean, did you screw the plastic piece back in? I have pictures if you need a reference on what I'm saying

wanabebuff

Before it is screwed back in:


After you screw it back in:

sleepers91hb

I tried that on my old FITV but that didn't do anything for me, I actually bought a brand new OEM Honda FITV and IACV a month ago so I am almost positive it is not either. I thought one would be the problem that's why I bought new ones but didn't fix the problem.

Thinking it is my ect sensor, coolant temp sensor possibly is bad telling my ecu that the engine is still cold thus the IACV is staying open even though the car is hot.... or I have an exhaust manifold leak or something of that nature.

Thanks for the advice.

Will keep everyone posted as I try more trial and error. Hopefully I wont go broke on the way!

wanabebuff

I figured, I just thought I'd ask, mine had similar symptoms. Good luck man

bigpunn421

did you ever fix your problem?