mattssi

Before the search pollice come out I would just like to say that i spent the better part of the morning searching through all the iacv topics for an answer to my question, so if you want to be a doush bag about it, please do not post.
I have a y7 block and a z6 head. sk2 intake manifold. I am currently using an iac off of a y8(not sure of the year) It was on my last setup and worked just fine. Now on this setup, the revs just bounce between 1500 and 1700 regardless whether or not the iac is plugged in or not? I tried to adjust the idle screw on the throttle body, No dice. It is all the way tight and it didn't een make a difference. The car surges when you are just trying to cruise like in 3rd(every gear) it will all of a sudden just cut out like you let off the gas, then you really have to put the pedal down to get it to start going again and it causes the car to jolt. It also has a bad sputter around 1500 rpms.. Please somebody help me diagnose this..

JDM-97CX

Unplug the TPS and take it for a drive.

mattssi

What will that do? Won't that put the car in limp mode?

mattssi

I forgot to mention. This is a obd1 94 civic HB. Running a p28 ecu.

mattssi

I'm sure somebody has resolved an issue like this before?

mattssi

This is what i am talking about, of course this should help get my thread noticed...

Luserkid

That IAC is dirty as all hell. Also it looks like its OBD0.

Did you try your fast idle?

mattssi

That isn't my iac, just a pic of one. I haven't bothered with my fitv, do you think it could be the culprit. Side note, I took off the line going to my fpr, and it did nothing to my motor, the idle didn't go up or anything?

mattssi

So far tonight I changed the iacv and took the back off the fitv and turned the round plastic thingy till it was completely tight, Hooked back up the iac and bolted it all together. Started it up and it idled at 2k, but after the car was warm, it never dropped, it just stayed at 2k even if you tap the gas. It would go up then drop to like 1200 and go straight back to 2k??? any ideas. I used carb cleaner to find a vac leak, but no luck. I am using a dx harness on this setup. The only cel's i have are for vtec(that isn't hooked up yet)

CrotchRocket

First, make sure you don't have air in your cooling system.

Your FITV might be bad. It adjusts the idle when your engine reaches operating temperature, bringing it down to 750rpm.

mattssi

I don't see how it could be bad all a sunned, it was just on my last setup and worked just fine. Is there any wiring issues associated with using a dx harness and a p28 ecu? I have to add vtec wires i know, Haven't done that yet, but all other cel are clear. I had one for a iacv, but i replaced and now that cel is gone.

Relic1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mattssi &raquo;</TD></TR><TR><TD CLASS="quote">I took off the line going to my fpr, and it did nothing to my motor, the idle didn't go up or anything? </TD></TR></TABLE>
that is a sign of a vacuum leak in that hose. (not sealing up to the FPR correct which ups the fuel and would make it idle high)

mattssi

I checked for a vac leak there by spraying carb cleaner all over that area. I am stumped here. I have solved alot of these issues before, I have't had this much trouble getting an idle right before. It is doing that whole sputter at 1500. Like if you light throttle it at 1500 the revs will just bounce. And if you are driving light throttle at 1500 is makes the whole car lurch

b18ccivics

check the voltage for the tps at closed throttle and wide open throttle

PINEAPPLE

bump this topic up cuz I have the exact same problem.

mattssi

I am using a dx Throttle body that has a riveted in tps. It shouldn't be messed up. I was using this Throttle body on the stock motor no probs just a few days ago. No issues. Besides the fact that the rings let go.

egyolk

iTrader: (1)

Bump, i have the same problem as well, i've cleaned my iacv really well but havent messed with fitv yet.. sigh still bouncing

mattssi

Does it cut out when you are driving in part throttle? Like you took your foot off the gas? It makes driving really stressful.

Steps25

hello all....Yes, my first post here. I post regularly on Mustang forums as owner of an '05GT.

I recently acquired a 2000 Civic CX and I'm experiencing this exact same problem. Bouncing revs up then down etc. and a sputter that causes the car to nearly stall at about 1500

-I figured it was some kind of vaccum leak but I can't seem to locate a leak.
-I've scanned the OBD for codes and no codes are being thrown.
-I've removed the throttle body, removed the sensors and thoroughly cleaned the throttle body/IAC etc. and put it back together with a new gasket to be sure I had a good air seal. This still didn't fix the problem
-I hooked the scanner back up and noticed that the MAP sensor readings were jumping all over the place. Then, when I would hold the throttle open a bit the MAP sensor would read consistent. So I pulled the MAP sensor connection and the car stopped the up & down idle for about 5 seconds.
-I keep thinking it must be a vacuum leak I just can't find. Anyone?

mattssi

Sounds pretty much the same. I know that somebody here has the answer.. They just need to chime in.

Steps25

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Steps25 &raquo;</TD></TR><TR><TD CLASS="quote">hello all....Yes, my first post here. I post regularly on Mustang forums as owner of an '05GT.

I recently acquired a 2000 Civic CX and I'm experiencing this exact same problem. Bouncing revs up then down etc. and a sputter that causes the car to nearly stall at about 1500

-I figured it was some kind of vaccum leak but I can't seem to locate a leak.
-I've scanned the OBD for codes and no codes are being thrown.
-I've removed the throttle body, removed the sensors and thoroughly cleaned the throttle body/IAC etc. and put it back together with a new gasket to be sure I had a good air seal. This still didn't fix the problem
-I hooked the scanner back up and noticed that the MAP sensor readings were jumping all over the place. Then, when I would hold the throttle open a bit the MAP sensor would read consistent. So I pulled the MAP sensor connection and the car stopped the up & down idle for about 5 seconds.
-I keep thinking it must be a vacuum leak I just can't find. Anyone?
</TD></TR></TABLE>

"Your FITV might be bad. It adjusts the idle when your engine reaches operating temperature, bringing it down to 750rpm. " -crotch rocket


OK. It was the FITV on mine. I may have a slightly different set up than you but it sounds like the same problem. My FITV is bolted to the throttle body with four 8mm bolts. The last time I took off the thottle body to clean it I didn't mess around with the FITV too much because of the way that the electrical sensor sealed on the FITV. This time I first removed the hoses running coolant to the FITV and plugged it with a golf tee. The car ran fine. So I took off the FITV, took off the sensors and cleaned everything, especially the "little spinning rod thingy?" inside the FITV. I put it all back together, went for a long test ride...she's running fine.

Your FITV may be set up differently but I'd check into it. Here is a thread that helped in my research. I have a different FITV but the concept is the same.
https://honda-tech.com/zerothread?id=699787

CrotchRocket

oversteerINGS - you can clean your IACV all you want but if the mechanism does not function properly, you will get a bouncing idle problem.