checked FITV looked clean but still cleaned it up
adjusted idle screw as far as i could took idle down 300 rpm
cannot find a vaccum leak anywhere

95 civic ex with d15b7, idles around 2k on cold start warms up some and drops to 1650rpm..

Ive held my hand over intake and car did not die out, held my thumb over throttle body holes inside intake and top one idle went down from sounds of it, bottom hole didnt do nothing..

I have taken brake cleaner and sprayed every vaccum line i could find and around the whole intake mani and nothing...


What else can i look into doing/checking to find out this problem... Timing or what, belt does look like it has some play in it when running and when off you can push the belt a bit more then you should..

 

Have you cleaned the IACV? It may be dirty or bad. Any CEL codes?

 

no cel on, iacv didnt look bad or clogged... gonna take it back off and clean it since i have stuff to clean it with now..

 

anyone...

 

When the engine is warm, you're saying the idle sits at 1650rpm and doesn't surge?

If yes, check the TPS/throttle stop screw. Sounds like your throttle is being held open more than it should be.

 

is there a gasket between the intake mani and the throttle body? correct torque?

 

yes, there is a paper gasket in between

 

Yes thats what im saying, once and a while it will surge about 3 times up and down then stop when i come to a stop light..

What are you referring to also, the only screw that ive seen was the gold flathead screw on/above the throttle body and ive adjusted that all the way to the lower idle side and it only took it down probally 300 RPM...


As i said ive sprayed brake cleaner over every vac. line and intake mani and throttle body for leaks and the idle didnt die down or the car didnt die out, so thats where im lost..

Ive searched trough various threads on here tried everything that someone has suggested to other ppl to do and im at a stand still not knowing what else to try..

 

If you follow the throttle cable, it's attached to a cam/rotor on the throttle body. When your foot is off the gas, that piece has to rest against something...that something is the screw I was referring to. Most people 'not in the know' start messing with this because it directly affects the position of the throttle. The screw you messed was the correct one (there's usually a plastic cap covering it).

Grab a meter and measure your TPS voltage @ idle. Should be .49v or less. If that measures ok, and you're sure your coolant has been bled properly, unplug the ECT and measure its resistance. Should be ~300ohms on a hot engine (<180*F). On a cold engine, the IAT and ECT will measure about the same resistance, so you can use that as a sanity check of sorts.

P.S. I'm also making the assumption that you're running a stock engine and matching ECU as I'm pretty sure the D15B7 didn't come in a 92-95 Civic Ex...the D16Z6 did.

 

Theres 2 nuts on there that i have checked and still have factory paint markings and have not been adjusted cause the paint markings match up.. Those where the only things i could think of that you was referring to..

Yes, the last owner blew the stock z6 on a 125shot (douche) and then installed a d15b7 and the po6 ecu..

From the looks of the dizzy the timing had been advanced, and i twisted it back to where the stock bolt marks was on the dizzy and it calmed the idle down some then after i adjusted the idle screw all the way to lower the idle.. After all that i went from 2k rpm to 1650 rpm..

Ive read over all the tps voltage and ect, but i was just to lazy to find a meter and tap wires ect to even find out.. Guess ill have to get unlazy and check all that..

Another thing the last owner left the thermostat out so its running no t-stat also.. Im wanting to put one in due to the fact its snowing here and it only gets really hot when sitting at idle for 5 mins other wise it blows warm/cool air.. I was wondering if that had something to do with the idle also, read a old thread on here where ppl was talking about it but i dunno..

thx for all the info, im going to find a meter since the fuse blew in mine..

 

Mine was idling high the plastic piece was completly loose. did you tightin the plastic piece of your FITV.

https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/how-fix-your-idleing-woes-fitv-iacv-2153910/

 

I will check into that thx for the link..


Took the iacv off and cleaned it earlier, put it back on no worky.. sprayed BP cleaner around everything once again just to see if i missed anything nothing..

So i pull my tps sensor plug off and map sensor plug off and it will idle around 1100rpm, then if i plug my finger over the iacv hole in the intake mani it idles alot lower around 800rpm..

Will it hurt just to run the damn car without tps and map sensors plugged in, it ran fine for 5 mins without them plugged in and when i hit the gas it didnt die out or act funny..

But also now when i plugged them both back in im having a surging idle 1k-2k rpm constantly, this happened after i cleaned the iacv and checked for leaks around the manifold with BP cleaner..


So TPS maybe bad? dunno didnt get the volt meter guage to test them, will do that tomorrow and find out..

 

see step number 5 on that link i pretty sure thats your problem.

 

Done that tightened it up a few turns till it was snug and put it back on and it idled at 2k for about 10 mins then it would start idling from 1k-2k..

hell i dunno, picking up another used throttle body with sensors for cheap and im gonna try that..

 

No thermostat - yikes...which also might mean you need to re-bleed your coolant. Air bubbles in the coolant system will cause a surging idle too.

 

Yea i just rebled the whole system shot out some big air/coolant and whatnot, done it for about 5 mins till just coolant was coming out..

Started it still idles high, then when i gas it the car will start to iratic idle and wont stop..

Got fuse put in my meter but im not sure that its working right, also which wires to i tap into every single one of them or what.. I seen the thread a while back but i cant remember off top my head..

 

picked up another throttle body with all sensors, put it on and made it worse..

Idles 3krpm and the tps sensor whistles loud as hell, so i put the old one back on with high irratic idle..

Also from the looks of it they have a d15b7 motor and the intake mani is from a z6 motor, had to buy a gasket today luckily i took the t-body with me and a b7 gasket was clearly to small so i had them get me a z6 gasket and wa bam it fit..

So im not sure if that may have something to do with the high idle ect..

Also after i took the t-body off the car to put the old one back on i noticed something, on the old one when i took it off and pulled the line off the back of the FITV no coolant shot out.. Well when i put the t-body on that i just picked up and took it back off coolant shot out of the rear hose from the FITV.. seems like its not flowing trough the one that was on the car from the start.