Ahhhlee

Hi everybody, hope everyone is well; so let me get straight to it...Vehicle= 1993 civic si hb engine=d16z6 (Canadian version)

1) My previous idle problem was whenever i stopped at a random stop sign, the idle would surge/hunt going down and then up between 400-800rpm.

So did some research, and came to the conclusion that i need to clean my i)EACV ii)FITV iii) TB (while i was at it)

Reassembled after everything was cleaned/dry and fitted new TB gasket and EACV/FITV O-rings, FITV adjusted properly, throttle cable adjusted within spec, bled cooling system. The MIL light didn't stay on after initial start-up (safe to say no codes). On initial start rpm holds great at 1500 rpm when engine is cold . Then when engine reaches operating temperature holds beautifully at 750 rpm.

2)However the second i get going and stop, or i touch the gas slightly after engine has warmed up, idle will surge/hunt up and then down between 1300-1000rpm, although eventually sometime comes back down to idle around 800rpm.

possible problems ruled out based on my limited knowledge is a vacuum leak; i read that cause the rpm to spike and stay up, seems like i don't have a vacuum leak; but for sure i could be wrong, because I don't know all the symptoms of a vacuum leak.

>>>i haven't done the inspection to see if the FITV is malfunctioning by checking if there is still suction at the lower hole/port in throttle body when engine is at operating temp.

help/advice would be greatly appreciated as to why the new idle would surge/hunt still and why its in the opposite direction?

BlackEM2

i know the problem with my teg was the iacv (idle air control valve)

blaze_125

isn't the IAC the same as the EACV?

Former User

Try unplugging the O2 sensor to see if this prevents the problem.

Also check output voltages of the TPS and resistance of the ECT sensor.

Ahhhlee

yah sorry fellas i used the terms in the Honda manual; the Honda manual names the IACV to EACV (really weird why they would do that), but both are the same.

So RonJ@HT ill try unplug the O2 sensor to see if this prevents problem, but i don't have the tools for checking the voltage of the TPS(throttle position sensor..correct me if im wrong) or ECT (not too sure what this is...am i safe to assume u want me to check the voltage of the sensors attached to the throttle body?)

will get back to you....

Former User

My low impedance digital multimeter cost me $15. This is an absolutely essential tool if you want to do your own car repairs.

The TPS is attached to the throttle body. It should output ~0.5V at closed throttle and ~4.5V at wide open throttle.

The ECT (or TW) sensor is located below and slightly forward of the distributor and has a 2-wire connector. When the engine is fully warmed up, unplug the ECT connector and then measure the resistance across the two sensor terminals. It should read 200-400 Ohms.

averyvm

iTrader: (1)

Do you know what the resistance should be on the IAT when full warmed up in hot-as-a-******** Georgia

Ahhhlee

update: my apologies, i decided to forgo all the checks regarding sensors because i had a feeling i didn't have to meddle around with those things since i had no mil/ cel on; thank God.

I instead decided to go and re-bleed my coolant system, and thank God everything is a-ok. I guess even with a minute amount of air in the coolant system, it can throw off the thermo-wax plunger in the fitv, which you all know functions by/through coolant & its temp.

Now i noticed something else; once i start the car up and when it reaches operating temp, the car idles beautifully and holds @ 750rpm solid.

but when i go for a drive or rev it gently up and let it come back down gently the idle holds just under a 1000rpm. ( i believe its around 800-900 rpm; it doesn't surge, its just i'm estimating with my dash tach)

whats weird is i read the manual, it said that under loaded conditions (ex. accessories on) that the idle should increase, but my idle on the other hand decreases depending on how many accessories are on. (for example: starting @ 900rpm, if fan is place on, rpm decrease by -50rpm, when headlights turned on another decrease by -50rpm, when rear defroster is turned on the idle will decrease by another lets say -100rpm.

to me this makes sense how my idle is behaving, since the motor is under a loaded condition it would be robbed of power, from my basic understanding.

i know if I am unhappy with my idle after i drive or rev it up, i can readjust fitv by screwing it in a little more, and then re-bleed coolant system, but is it ok for my car's idle to drop when accessories are turned on? is the honda manual right???

besides the above minor problem, i just have to reduce the slack in my throttle cable, to have a better feel in the gas pedal and i'm set.

once again thanks for all the help/advice

Ahhhlee

ttp

freeagent

i think what the manuel is trying to say is that it will try to compensate for the accessories, but im pretty sure your idle should still drop some, like it should try to idle up when power steering is active as well

Ahhhlee

yah seems all gravy fellas, much appreciate the help. {worked great for resolving my surging/hunting idle problem; i think all i had to do was clean my iacv, but im happy i cleaned everything.} just a reminder for all those who go ahead in cleaning there throttle body, iacv, and fitv.

1) make sure to have a lot of rags handy
2) make sure to have a lot of penetrating oil (Pb blaster) ready to use, especially for the 3 bolts connecting the fitv to the TB, i snapped one of those bolts because i didn't notice that two out of the three bolts have there ends exposed on the outside of the TB. So.. spray penetrating oil good on the cap of the bolt and on the end of the bolt that is exposed on the outside of the throttle body & let sit for a little while before trying to unscrew (10-20 min); this is done when trying to initially disassemble fitv from TB.***
3) screw back fitv plunger in where it was b4 (remember where white part of plunger was through the opening on fitv, not the metal *** part lol); if it was too loose in there to begin with screw it in all the way till its nice and snug
4) bleed coolant real good before starting car after reassembling. when motor is cold open rad cap, then unscrew bleeder screw on rad pipe connected in front of valve cover. Then when coolant flowing with no bubbles screw back down full rad cap and bleeder screw. Start up car, then slowly slowly unscrew bleeder screw on rad pipe connected in front of valve cover and make sure again no bubbles in coolant coming out and that coolant is flowing smoothly.

thanks again for z help/advice

***my car is originally from Ontario, whole whack of bolts are seized in my car. thank God i only snapped one so far. Oh yah by no means is this a walk through of cleaning the iacv and fitv, there is a great walk already posted within these forums. Although, this is just my experience of what i had gone through and some small recommendations to others.