Rep Power: 563

Ok here we go again. There was once a thread on this issue but I can't find it and I want to know if there have been any new discoveries.

My 2001 Si (EX US) is having problems sustaining idle when I stop. Last night it rained and with the car soaked I went out for coffee this morning and the car would not only lose proper idle it totally stalled out twice!

Here are two ideas that I have along with a pdf that I found.

1) Brake Booster malfunction: Since this only normally occurs when stopping I thought that the Booseter may be done.

2) o2 Sensor: My Air/Fuel guage is not wired into the o2 properly and may be messing with the idle of the car. When the wires are damp the car actually stalls. Any thoughts on this one?

3)

 
Rep Power: 310

Could be brake booster.. but I think if its malfunctioning that it would be hard to stop the car.

Could be 02 sensor telling the ECU to tweak the timing and A/F mixture. Makes me wonder if you put it back to stock for testing purposes if it would fix it.

Definately could be like the TSB says.

 
Rep Power: 563

Yeah, I talked to a Honda tech and he basically told me that I should remove the Air/Fuel guage wire and see if it helps. He hasn't got that bulletin number because it was raised in the US and not Canada....wtf, don't they share information or anything. Either way, he said that if removiong the wire doesn't work that he'll investigate the bulletin.

 
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Gonna sticky this.

This is the first time I have actually seen a TSB for the stalling problem. This should give people who have this problem some ammunition to use against their dealers.

... thanks to Pharoh

 
Rep Power: 563

Yeah, hope we can get some results as this is one of the most annoying problems I have ever encountered.

 
Rep Power: 563

Ok, here's an update on the whole issue.

I talked to my dealers shop manager (Marco) and he told me that he actually followed the procedure in the TSB the last time I went in to get the alternator changed out. So by process of elimination we have concluded that the o2 sensor is gone.

1) Idle drops and sometimes stalls completely when the car stops.

2) Car hesitates at high RPM's

3) Gas getting eaten like cake at a Jenny Craig convention

They are gonna do the work as a warranty repair and hope that Honda doesn't come back saying that the part they replaced was defective only because the Air/Fuel guage was tapped improperly into the sensors wires. I don't beleive it was but if you look at the wires they actually change color from the bottom to the top so I guess it's possible.

But it's worth mentioning that the TSB is legit and all those with similar problems should get that checked out and failing that replace the o2 sensor.

I'll keep y'all posted on the outcome as I'm hoping to get her in after work tomorrow.

 
Rep Power: 563

Ok, here is the long and ongoing process to this point....

The o2 sensor was replaced and I have seen the following results:

1) gas mileage has improved
2) hesitation at high RPM's has gone

But....

They took the car out and tested it with the AC on.. The first thing I did when I got the car back was turn it off and about 10 minutes later the idle dropped out again.
Beleive me when I tell you that waiting in a two hour traffic jamm twice (thanks to the blackout) with a car that can't sustain idle is NOT FUN!

Went back to the shop the next morning and we did the following:

1) drove the car while toggling the AC on and off to demonstrate the problem.
2) tightened a screw (sorry, the name of it escapes me) by the throttle cable bracket to adjust for possible recoil problem.

Results: Nothing...problem persists....

I have this lovely TSB attached at the beginning of this thread which unfortunately is no good in Canada since it was made in the US and the warranties are different there I'm told.

BUT...

They have finally decided to listen to me and replace the IAC valve as per the TSB. I go in Wednesday morning to have it changed. If they can prove that this has been done enough times in Canada then we'll be able to get a TSB made for Canada...Fingers crossed.
For those who don't know what the IAC valve is it's the module attached to the base of the left of the throttle body with the two small black hoses going into it.

Definition: The IAC valve increases engine speed when engine temperature is low by venting air into the air duct behind the throttle plate.
The IAC valve is incorporated into the throttle body.

Again, I'll keep this updated.

 
Rep Power: 0

I don't understand how they can say this TSB does not apply to Canada. That's one of the dumbest things I've ever heard. That bulletin clearly says ALL 2001-2002 Civics. From their crazy logic, this must mean that all Civic coupes are excluded from this warranty in Canada since all coupes are made in the US. And I have never seen a TSB specifically released for Honda Canada only.

BTW, that TSB does not mention anything about replacing the IAC valve. It just recommends udpating the software.

 
Rep Power: 563

Yeah, I don't get the logic behind the whole US/Canada thing either.
They updated the software when I went in for the o2 sensor. But the TSB is what made us think to replace the part. Hopefully we can get to the end of this and figure out what the hell is wrong with the car....

 
Rep Power: 0

Did it work? How often does the idle drop? Where does it drop from and to? Thanx.

 
Rep Power: 563

Good news, the IAC valve did the trick. The car was road tested with the AC off for 30 minutes hooked up to the EGPM. It was taken on the highway, in residential and went through hard braking trying to replicate the problem. Happy to report that it behaved well. I drove the car home and did the same testing and got the same positive results.
So I think that's it folks...This is likely the source of the problem for other members that have been having the same problems.

Hopefully this thread will help some as I can atest to how big a pain in the *** it is.

Any questions, please don't hesitate to ask them here and I will answer them as quick as I can....

Cheers!

 
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what is the TSB

 
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see the attachment in the 1st post of this thread

 
Rep Power: 563

Thanks Ronin...that TSB is pretty helpful and I'm glad I found it as I credit it for solving my problems with the idle which is still strong by the way....he he he.

 
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I had only one wire of the IAT sensor not hooked up and it didn't stall.... just a thought

 
Rep Power: 349

Hey, pharoh, was your check engine light on when you were having these issues? I'm afraid that because I've boosted the car, they won't honor any kind of warranty.

 
Rep Power: 563

Nope, the IAC won't trigger the "Check Engine" light at all. I don't know what to tell you about the boost but it prolly depends on the dealer. I don't know that boost is related to the IAC valve anyway..

 
Rep Power: 0

the ICV will trigger the cell if its a problem. It did it with my car. i took it to the dealer and they pulled the code and it said the ICV had something wrong, but it fixed itself cuz my car doesnt rev up and down anymore. Dont know how, besides resetting the ECU.