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Discussion Starter #1
Well what causes the car to rev itself to 2500rpm wile driving or changing gears? And thats whithout pressing the pedal.

I can be driving down the road in first gear, ill press the clutch and put it in neutral WHITHOUT pressing the gas pedal, now although the car is crusing down the road inneutral, the engine rpm reaches 2500rpm, and after almost 8 seconds the rpms goes down to normal..
 

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FITV/IACV/Floor mat/Size 18 Jordans/Throttle Cable/Dirty TB/ Shitty OBD2 Y7/Y8 2 wire vs. 3 wire swap issues, Batman vs. Superman, Zika Virus, unladen air speed velocity of a swallow.

To be driving in first gear, and press in the clutch, your clubber foot will be on the loud pedal or you have a throttle hang issue.

What year Pontiac?
 

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Discussion Starter #4
It idles at 2500 rpm.. And if im still waiting for the light, it takes a few seconds for the idle to automatically drop to normal..

Wouldnt know how to explain it the best I can is everytime before I shift the car idle goes up(like it revs itself) even when I come to a complete stop and put it neutral the rpm reaches 2500 and stays there for a few seconds..
 

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ΩM£GA;4978378 said:
It idles at 2500 rpm.. And if im still waiting for the light, it takes a few seconds for the idle to automatically drop to normal..

Wouldnt know how to explain it the best I can is everytime before I shift the car idle goes up(like it revs itself) even when I come to a complete stop and put it neutral the rpm reaches 2500 and stays there for a few seconds..
fast idle air control messing up
vacuum leak
crome chip in the ecu
or iacv going out.

You car is hunting. meaning the rpms will go up and down till it finds out how to get the idle it is looking for.
the problem is cause by one of those things i said up there ^
 

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Discussion Starter #7
fast idle air control messing up
vacuum leak
crome chip in the ecu
or iacv going out.

You car is hunting. meaning the rpms will go up and down till it finds out how to get the idle it is looking for.
the problem is cause by one of those things i said up there ^
Well... I beleive I finally found the problem... Hopefully. After replacing the map sensor(with rubber gasket), ECU, IACV, I came across something that I didnt noticed before... Near the intake manifold there is a vacumm leak, you can clearly hear it and dont understand how I missed it...

Anyways with the engine hot ...:willy_nilly: I sprayed carburetor cleaner, and paid close attention to any idle difference... Nada.. And by accident I moved the PVC hose and wala! I move the pvc hose and the pvc valve moves because more Im able to hear more air escaping..

Since the pvc valve is new it either came loose, or its not sealing properly...
 

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Discussion Starter #8
Almost forgot, the car is a 2000 civic ex 5spd..

Well fixed the pvc valve leak... Car idles a lot better when iys parked, BUT the issue is still there.... Whats worse I can still hear an air leak near the intake, checked each hose individually and nada...

Well after hours of frustration I made my brother drive the car.. And I paid attention on the RPMs and here's whats going on...

1: Car gets placed on 1st gear, and begins to drive.
2: Clutch is pressed, wile gas pedal is released, getting ready to shift in to second gear... The car suddenly revs itself to 2500rpm, and it will stay there until he either waits for it to drop, or shifts in to 2nd..
3: Again clutch is pressed, yet again with the gas pedal released, getting ready to shift in to 3rd, same thing the RPMs suddenly rise to 2500
4: And same thing for the rest of the shifts/down shifts..

Basically everytime hes getting ready to shift the RPM's suddenly rise to 2500 and will stay there for a few secs. At a stop the car's RPM's will be at 2500 and will take a few seconds for it to drop to mormal..

*Checked the throttle cable, and made sure it wasnt tight..
*Adjusted multiple times the throttle screw
*Checked each hose individually for for any sings of a leak
*Replaced the IACV, disconnected the IACV valve and my RPM's dropped from 800 to 400ish so it is working
* Replaced my map sensor(with rubber O-ring)
* Cleaned the throttle body
* Checked for a fast idle air control valve... My throttle body doesnt have one(or I coulnt find it)
* Removed any air in my coolant(at least I think so)

Any other suggestions? Im lost dont know what else to check... As a last resort im going to install the old ECU(even though it has 2 burned resistors for the IACV) im going to test it...
 

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Discussion Starter #11
Do the idle relearn. You dont just adjust the idle screw.

Check for vac leaks.
Most common is cruise control line on rear or manifold.
try cab cleaner around all vac lines and lower fuel injector orings
Well I finally found it.. I replaced the throttle mounting gasket and decided to install the old ECU... Problem fixed...

Installed the new ECU and almost imediateley it starting having idle surges, and yet again it yould rev up to 2500rpm..

My old ECU has 2 burned resistors which brings up p1508 "manufactuer control" ill replace the new ECU for yet another one, hopefully tomorrow and see how that goes.
 

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read the label on the ecu's


what are they?

why do you say 2 burnt resistors? can you get a multimeter tip in there to check for sure? some ecu's look nasty, but its 20+ year old flux discoloring
 

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Discussion Starter #13
read the label on the ecu's


what are they?

why do you say 2 burnt resistors? can you get a multimeter tip in there to check for sure? some ecu's look nasty, but its 20+ year old flux discoloring

Ill check the labels when I get home. Well im saying that there burned because the hole board looks fine, no signs of discoloring, BUT in one part it looks like 2 resistors did gave out and/or someone tried to re-solder them, leaving an obvious burnd spot, not to mention it does have a burned smell.

Im trying to post images and a video BUT its telling me I need grater post to post any links...so...
 

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post the http links to the images with a space somewhere, and slo or someone will edit the posts and show the images for ya
 

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post the http links to the images with a space somewhere, and slo or someone will edit the posts and show the images for ya
Ok the first image is the old fudged up ECU which is currently installed:



The second image is the new ECU I aquired, it doesnt throw a code, it idles worse than my fucked up one, not to mention the RPM isssue wile driving. Will replace it tomorrow morning.:


And last but not least the burns...:

 

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Discussion Starter #16
Bump.......

Well..... I managed to try 3 different computers(All P2P-A12)
And SAME results..so what are the odds of all of them having the exact same issue?(High rpm wile shifting and no cel) so .. either im suppppper unlucky OR the ECUs are in good working condition and my problem is with the IACV, vac lines or wiring...

For now im going to stop working on this issue since its been a headache... Ill figure this out later..
 

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Without touching the gas pedal start the car. What does it idle at? Does the idle stay at a constant speed?
 

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Discussion Starter #18
Without touching the gas pedal start the car. What does it idle at? Does the idle stay at a constant speed?
Well each ECU had slight different idles... This last ECU seems like its the best one since the car idles perfect from what I can tell(800ish).. But as soon as I started driving the car 2500 rpm... Yay!

It would seem like if the throttle was staying a bit open or if the idle air valve would get stuck open for a few seconds causing the sudden RPM increase.... BUT why does it only happen wile driving and NOT wile in park..

I talked to my local mechanic... And told me that my tranni was slipping.... Well I told him mine was manual and just gave me an "Oh" and then suggested the IACV was bad... Well I tested a few as well and nada..

Well tomorrow as a last attempt... Im going to disconnect the IACV and drive it with the new ECU... If the rpms dont go up while shifting Ill start from there... I cant beleive I didnt thought of that before...:whistling:
 

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Discussion Starter #19
Well i feel dumb... Dont hurt me XD

Sorry for double post, tried it, something I should of done first... And well yeah having the IACV disconnected solves the problem with the high rpm while shifting..
 
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