Revving dropping idle need help
Revving dropping idle need help
We have a 97 Civic dx 4 cylinder 5 speed car...
Admitted the car has sat undriven a couple months,
Now it has a weird intermitted problem it didn't have when parked.
The idle will be fine and then will start to hunt or fluctuate between 1000 and 2000 RPM ,
Then it will stop doing it for a spell then starts again,
It doesn't stall and the AC being on or off doesn't effect the problem,
Otherwise the car runs super fine,
Anyone have some ideas where to start looking to resolve this annoying problem,
Many thanks
Cheers,
P.
Admitted the car has sat undriven a couple months,
Now it has a weird intermitted problem it didn't have when parked.
The idle will be fine and then will start to hunt or fluctuate between 1000 and 2000 RPM ,
Then it will stop doing it for a spell then starts again,
It doesn't stall and the AC being on or off doesn't effect the problem,
Otherwise the car runs super fine,
Anyone have some ideas where to start looking to resolve this annoying problem,
Many thanks
Cheers,
P.
Joined: Sep 2002
Posts: 51,241
Likes: 20
From: NV
Rep Power: 812 










Re: Revving dropping idle need help
try to clean out the intake system, IAC valve, throttle body, etc. prolly just clogged up with carbon.
Re: Revving dropping idle need help
ya, im thinking ur IACV, throttle body, or ur injectors are clogged a little?
id get deep creap or some carb cleaner and spray the IACV out, as well as the TB and then run some seafoam or something through the gas tank and engine.
my GF's car was the same way after we went on vacation for 4 months to Europe and that's how i fixed it.
id get deep creap or some carb cleaner and spray the IACV out, as well as the TB and then run some seafoam or something through the gas tank and engine.
my GF's car was the same way after we went on vacation for 4 months to Europe and that's how i fixed it.
Re: Revving dropping idle need help
its on your throttle body, on the back of your engine.
it has 3 screws holding it in, and has 2 or 3 coolant lines coming out of it.
i cant find any pics on it, but if u take ur intake off and look into the tube, u will see a small hole near the throttle plate. that hole is where ur IACV lets air in, so that it gets past ur closed throttle plate.
btw, IACV: Idle air control valve.
ill see if i can find some DIYs or pics of it. give me time.
it has 3 screws holding it in, and has 2 or 3 coolant lines coming out of it.
i cant find any pics on it, but if u take ur intake off and look into the tube, u will see a small hole near the throttle plate. that hole is where ur IACV lets air in, so that it gets past ur closed throttle plate.
btw, IACV: Idle air control valve.
ill see if i can find some DIYs or pics of it. give me time.
Re: Revving dropping idle need help
Many thanks for all the help,
I believe I found the IACV but I was without my metric 1/4 socket set and didn't get in there and clean that yet,
In the meantime I stopped a small new repair shop at the end of my street,
They got in there and said at first it was one then two idle sensors on the throttle body and that you cant replace just the sensors they are built into the throttle body you have to change the entire throttle body, a 500.00 plus part,
He also said that me spraying carb cleaner down the intake is what ruined the sensors, but I had the problem before I sprayed the carb cleaner in there
Does any of that sound right to you guys seems stupid to make sensors your cant change out,
I will still clean the IACV and see what that does
I believe I found the IACV but I was without my metric 1/4 socket set and didn't get in there and clean that yet,
In the meantime I stopped a small new repair shop at the end of my street,
They got in there and said at first it was one then two idle sensors on the throttle body and that you cant replace just the sensors they are built into the throttle body you have to change the entire throttle body, a 500.00 plus part,
He also said that me spraying carb cleaner down the intake is what ruined the sensors, but I had the problem before I sprayed the carb cleaner in there
Does any of that sound right to you guys seems stupid to make sensors your cant change out,
I will still clean the IACV and see what that does
Last edited by The13bats; Oct 8, 2008 at 02:53 PM.
Joined: Sep 2002
Posts: 51,241
Likes: 20
From: NV
Rep Power: 812 










Re: Revving dropping idle need help
technically the sensors are not sold separately, but a used TB off ebay is only $50. i sprayed carb cleaner all over the place and never had a problem. i soaked the iacv in carb cleaner the first time and its still fine years later. its better to clean the tb off the car tho so you can really scrub it. just spraying cleaner wont get all the dirt off.
Re: Revving dropping idle need help
Ok,
So I pulled the throttle body and removed the IACV
It had some carbon on/in it and I cleaned it well and the valve in it moves freely,
I reinstalled everything and the idea still fluctuates, just differently now
Also when you first start it now an SRS lamp lights up on the Tach for a few moments and then goes off,
So I still have a fluctuating idle and really need to fix it what should I try next???
So I pulled the throttle body and removed the IACV
It had some carbon on/in it and I cleaned it well and the valve in it moves freely,
I reinstalled everything and the idea still fluctuates, just differently now
Also when you first start it now an SRS lamp lights up on the Tach for a few moments and then goes off,
So I still have a fluctuating idle and really need to fix it what should I try next???
Re: Revving dropping idle need help
hmm.... thats odd...
take it to a few more shops. dont even tell em what the other place said.
btw, could be sensors (but im not too sure), but could also be like a vacuum leak or something...
sea foam it, and then take it in to get looked at by another 3 or 4 shops.
take it to a few more shops. dont even tell em what the other place said.
btw, could be sensors (but im not too sure), but could also be like a vacuum leak or something...
sea foam it, and then take it in to get looked at by another 3 or 4 shops.
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
Martinez8o5
Mechanical Problems/Vehicle Issues and Fix-it Forum
10
Jul 31, 2015 10:58 PM
EM_WON
Suspension Performance Modifications
4
Jul 22, 2015 06:49 PM
671civicLX
Mechanical Problems/Vehicle Issues and Fix-it Forum
1
Jul 4, 2015 04:02 PM





