Idle problem after high altitude trip
Moderators: RedRacer, spiffyguido
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- Lude Dude
- Posts: 17
- Joined: Mon Aug 09, 2010 11:57 am
- Prelude Model: JDM 94 Si VTEC
- Location: Peru
Idle problem after high altitude trip
Hi, please I need some advice. I have a 94 JDM H22A Honda Prelude. Until saturday my car was fine, Idle was at 800 RPM but yesterday I went to a trip to a city located at high altitude, when I got there the idle was crazy it goes from 1500 RPM to 3000 RPM, I thought It will be fixed after going back to my home town but nothing, it is the same, I have tried to reset the ECU and reset the idle but nothing works the idle keeps like crazy.
I have stage 2 brian crower cams, p28 ECU tuned with crome.
Please somebody help me.
Thank you!
I have stage 2 brian crower cams, p28 ECU tuned with crome.
Please somebody help me.
Thank you!
- spiffyguido
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Re: Idle problem after high altitude trip
Does the idle fluctuate? When you say 1500rpm to 3000rpm, do you mean that the idle surges between those two values, or does it hold steady?
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- Lude Dude
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- Prelude Model: JDM 94 Si VTEC
- Location: Peru
Re: Idle problem after high altitude trip
Hi, yes it surges between those two values. Exactly it goes from 1000 to 2000 RPM. Here is a video I have uploaded to youtube where you can see the problem.
http://www.youtube.com/watch?v=klOSWm-dvfY
Thank you.
http://www.youtube.com/watch?v=klOSWm-dvfY
Thank you.
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- Lude Dude
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- Prelude Model: JDM 94 Si VTEC
- Location: Peru
Re: Idle problem after high altitude trip
Also I have discovered that if I turn the ligths on the idle stays at 2000 RPM and it don't surges anymore.
- spiffyguido
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Re: Idle problem after high altitude trip
Nearly always, fluctuating idle problems are caused by a faulty Fast Idle Valve (Idle Air Control valve). In many cases, the valve itself is fine, but the coolant has run down and there is a bubble of air stuck in the valve causing it to work incorrectly. I'd try bleeding your coolant according to the service manual to see if that helps. It's possible some air might have snuck into the coolant lines during your trip. Is the coolant reservoir topped up?
- RedRacer
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Re: Idle problem after high altitude trip
Could also be that the FIT valve has worked it's way out of seat from the factory placement and the springs isn't in place where it needs to be and is creating a vacuum leak which is causing the up and down idle.
The process I am going to recommend is exactly the same as what is detailed in this AWESOME write up from SUPERHONDA.COM. Please note I am giving them ALL credit for their forum article.
Superhonda.com member Cautela has taken a lot of time and effort to make this super-great write-up, complete with imagery, etc. to help fix what I bet is your problem.
Check this link on their site and definitely give them props for the write-up if it helps you out.
http://www.superhonda.com/forum/f55/tro ... ms-259965/
I'm just too lazy right now to go into the detail that he has.
~ RR
The process I am going to recommend is exactly the same as what is detailed in this AWESOME write up from SUPERHONDA.COM. Please note I am giving them ALL credit for their forum article.
Superhonda.com member Cautela has taken a lot of time and effort to make this super-great write-up, complete with imagery, etc. to help fix what I bet is your problem.
Check this link on their site and definitely give them props for the write-up if it helps you out.
http://www.superhonda.com/forum/f55/tro ... ms-259965/
I'm just too lazy right now to go into the detail that he has.
~ RR
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- Lude Dude
- Posts: 17
- Joined: Mon Aug 09, 2010 11:57 am
- Prelude Model: JDM 94 Si VTEC
- Location: Peru
Re: Idle problem after high altitude trip
Thanks, I will check the IAC Valve, I hope it is ok because in my contry there are not replacements for this car. I will bleed the coolant. The reservoir tank is not topped it is half.spiffyguido wrote:Nearly always, fluctuating idle problems are caused by a faulty Fast Idle Valve (Idle Air Control valve). In many cases, the valve itself is fine, but the coolant has run down and there is a bubble of air stuck in the valve causing it to work incorrectly. I'd try bleeding your coolant according to the service manual to see if that helps. It's possible some air might have snuck into the coolant lines during your trip. Is the coolant reservoir topped up?
Thanks man I will also check the FIT valve, thats an awesome write up, I will follow the steps, I hope it fixes the problem.RedRacer wrote:Could also be that the FIT valve has worked it's way out of seat from the factory placement and the springs isn't in place where it needs to be and is creating a vacuum leak which is causing the up and down idle.
The process I am going to recommend is exactly the same as what is detailed in this AWESOME write up from SUPERHONDA.COM. Please note I am giving them ALL credit for their forum article.
Superhonda.com member Cautela has taken a lot of time and effort to make this super-great write-up, complete with imagery, etc. to help fix what I bet is your problem.
Check this link on their site and definitely give them props for the write-up if it helps you out.
http://www.superhonda.com/forum/f55/tro ... ms-259965/
I'm just too lazy right now to go into the detail that he has.
~ RR
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- Lude Dude
- Posts: 17
- Joined: Mon Aug 09, 2010 11:57 am
- Prelude Model: JDM 94 Si VTEC
- Location: Peru
Re: Idle problem after high altitude trip
Problem solved. It was the intake manifold gasket. I've changed it and problem solved.
Thanks for the help.
Thanks for the help.
- RedRacer
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Re: Idle problem after high altitude trip
Glad you got your problem resolved.
Thanks for letting us know what the upshot was.
Curious though, what led to the diagnosis of the gasket? How did you come to learn that was the problem?
Thanks for letting us know what the upshot was.
Curious though, what led to the diagnosis of the gasket? How did you come to learn that was the problem?
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- Lude Dude
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- Prelude Model: JDM 94 Si VTEC
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Re: Idle problem after high altitude trip
Sorry for the delay, I thought this post was closed. First I did what spiffyguido told me an also what you told me to do but those things were Ok, so I decided to disassemble the intake manifold, and there was the problem, the intake manifold gastket was broken. Thanks for all the help.RedRacer wrote:Glad you got your problem resolved.
Thanks for letting us know what the upshot was.
Curious though, what led to the diagnosis of the gasket? How did you come to learn that was the problem?
- RedRacer
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Re: Idle problem after high altitude trip
Ah! Ok, that's great to know. Thanks for the follow up and glad you got it working right.
No problems since you made the repair?
No problems since you made the repair?
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- Lude Dude
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- Prelude Model: JDM 94 Si VTEC
- Location: Peru
Re: Idle problem after high altitude trip
Since the repair I have no problems with idle , but since 2 days ago I have a little problem with the clutch, everytime I push the cluth theres is a sound like a bird or something like that.
- RedRacer
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Re: Idle problem after high altitude trip
Uh oh. Bad throwout/release bearing. Not such a bad thing, especially if you are able to do transmission repair work yourself.
You can drive it until it stops working, or you can fix it now. At this point I'd suggest going on and replacing all the major components, and check the rear seal and make sure there are no leaks from the engine onto the clutch plate. Good time to replace that too if you have any leakage. If you've got questions though, just post them in a new topic window.... I don't want a good transmission thread to be missed because we started talking about it under your FIT failure topic.
You can drive it until it stops working, or you can fix it now. At this point I'd suggest going on and replacing all the major components, and check the rear seal and make sure there are no leaks from the engine onto the clutch plate. Good time to replace that too if you have any leakage. If you've got questions though, just post them in a new topic window.... I don't want a good transmission thread to be missed because we started talking about it under your FIT failure topic.
- spiffyguido
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Re: Idle problem after high altitude trip
Also a good chance to swap out the axle seals.
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- Lude Dude
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- Prelude Model: JDM 94 Si VTEC
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Re: Idle problem after high altitude trip
Ok, I will start a new topic, thanks for the help.RedRacer wrote:Uh oh. Bad throwout/release bearing. Not such a bad thing, especially if you are able to do transmission repair work yourself.
You can drive it until it stops working, or you can fix it now. At this point I'd suggest going on and replacing all the major components, and check the rear seal and make sure there are no leaks from the engine onto the clutch plate. Good time to replace that too if you have any leakage. If you've got questions though, just post them in a new topic window.... I don't want a good transmission thread to be missed because we started talking about it under your FIT failure topic.
Thank you, I will look for that replacements.spiffyguido wrote:Also a good chance to swap out the axle seals.