JDM_SOHC

After i put in my p28 on my d15b, like the very next time i started my car it began to bounce the idle up and down up and down ect... Than i put my stock p06 back on and it still bounced up an down... Is it possible that when i put in the p28 it changed my fuel and all that stuff and it jammed/clogged something up "fuel pump, injectors"..?? Because i've tried everything else possible and i still cant find out why my idle is doing this.. I changed all vacuum lines, sensors, coolant, everything emissions wise except for fuel pump/injectors.. Anyone have any input on this one please share...

GdmLaz

did you try ur idle control valve ???

SOHCmaster

Its either IACV or TPS, if you are sure to have no vac leaks, thats all I can think of

komat

drive around it and it should go away

since hte cu got reset its learning

Jim Truett

Have you ever set the baseline idle at 470 rpm?

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by komat &raquo;</TD></TR><TR><TD CLASS="quote">drive around it and it should go away

since hte cu got reset its learning</TD></TR></TABLE>

Why is it that everyone thinks an ECU needs to "learn" how to run an engine. The only thing it "learns" are long term fuel trim adjustments which isn't going to cause this problem.

d15bcoupe

bleed your cooling system. sounds like you got an air pocket. had this exact problem and bleeding fixed it.

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">Why is it that everyone thinks an ECU needs to "learn" how to run an engine. The only thing it "learns" are long term fuel trim adjustments which isn't going to cause this problem.</TD></TR></TABLE>

I agree on LT and STFT values being learned, however, on my bone stock 99 hatch after disconnecting the battery, I will get a bouncy idle if I just start her up and take her for a spin. Coming to a stop, my idle bounces a little but does settle down after a few seconds.

Starting the car and allowing it to fully warm up (then shutting it down) gets rid of this 'problem'.

Does that mean the Honda ECU needs to learn some idle process? I won't say yes or no because it seems with some models, this 'problem' isn't present at all but I do know that I have to do this with my car.

If you doubt the ECUs need to re-learn idling routines, don't - its something quite real on other makes of cars - my old 89 Beretta being just one example.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">

I agree on LT and STFT values being learned, however, on my bone stock 99 hatch after disconnecting the battery, I will get a bouncy idle if I just start her up and take her for a spin. Coming to a stop, my idle bounces a little but does settle down after a few seconds.

Starting the car and allowing it to fully warm up (then shutting it down) gets rid of this 'problem'.

Does that mean the Honda ECU needs to learn some idle process? I won't say yes or no because it seems with some models, this 'problem' isn't present at all but I do know that I have to do this with my car.

If you doubt the ECUs need to re-learn idling routines, don't - its something quite real on other makes of cars - my old 89 Beretta being just one example.</TD></TR></TABLE>

Your 89 berretta is quite different then a Honda ECU. And yes, I still stand by that a properly running engine shoudl require NO "learning" to get the idle correct. Period.

EE_Chris

Don't know what to tell you - the first time I did a valve adjustment at 30k, I disconnected my battery and had this happen to me. The car wasn't but 10-11 months old at that time.

So, I still stand by what I say - if you've done something to your car where you've disconnected the battery and all of a sudden you have a bouncy idle, let it warm up till the cooling fan kicks on once - its free.

komat

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">Don't know what to tell you - the first time I did a valve adjustment at 30k, I disconnected my battery and had this happen to me. The car wasn't but 10-11 months old at that time.

So, I still stand by what I say - if you've done something to your car where you've disconnected the battery and all of a sudden you have a bouncy idle, let it warm up till the cooling fan kicks on once - its free.</TD></TR></TABLE>
same here thats what i beleive too

everytime my ecu gets reseted my idle will bounce
after my car warms up . it will go away just as your stated

i know i have no vaccum leak or whatever leak

conekiller

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PK SPEED &raquo;</TD></TR><TR><TD CLASS="quote">Its either IACV or TPS, if you are sure to have no vac leaks, thats all I can think of</TD></TR></TABLE>


Vaccuum leaks won't cause surging.

EE_Chris

Vaccum leaks are a MAJOR cause of idle surging - on MAP based cars anyway.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">Don't know what to tell you - the first time I did a valve adjustment at 30k, I disconnected my battery and had this happen to me. The car wasn't but 10-11 months old at that time.

So, I still stand by what I say - if you've done something to your car where you've disconnected the battery and all of a sudden you have a bouncy idle, let it warm up till the cooling fan kicks on once - its free.</TD></TR></TABLE>

Perhaps you adjusted the valves out of spec. Poor vale adjustment WILL cause bounding idle. Sure, the ECU can learn to correct problems that it see's... but that still doesn't mean it needs to "lean" to be able to properly idle a correctly functioning engine right away. It should not need to do this. Thats all there is to it.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by komat &raquo;</TD></TR><TR><TD CLASS="quote">
same here thats what i beleive too

everytime my ecu gets reseted my idle will bounce
after my car warms up . it will go away just as your stated

i know i have no vaccum leak or whatever leak</TD></TR></TABLE>

So wait.. You know you have an issue with your car... And yet you still "believe" the ECU needs to learn to correctly idle the car under normal conditions? Its learning to compensate for the problem you have at hand. Thats completely different.

Jim Truett

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by conekiller &raquo;</TD></TR><TR><TD CLASS="quote">Vaccuum leaks won't cause surging.</TD></TR></TABLE>

Please don't post misinformation. Someone may actually believe you.

With a vacuum leak comes a lean condition at idle. The ECU will toggle the IACV from high to low in order to reach the ideal AFR. If the ECU is unable to bring the idle within spec through the IACV, it will remain in a continuous loop of surging until the vacuum leak is repaired.

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">Perhaps you adjusted the valves out of spec. Poor vale adjustment WILL cause bounding idle. Sure, the ECU can learn to correct problems that it see's... but that still doesn't mean it needs to "lean" to be able to properly idle a correctly functioning engine right away. It should not need to do this. Thats all there is to it.</TD></TR></TABLE>

Nope, sorry - I've adjusted my valves every 30k since I've had the car and it does this every time. The idle doesn't just start bouncing around upon start up - it happens when the engine is cold, you drive a short length and come to a stop - that is when the bouncing begins.

I'm not saying that the ECU has no clue on how to idle the engine - it certainly does not need to learn in that sense. However, there are ECU's that need to go through an idle re-learn procedure. It exists - don't doubt it. Its to compensate for load & temp - things like that.

It may not exist on Honda ECU's - so what? There is absolutely NO harm in promoting the idea that IF you disconnect the battery and IF you all of a sudden get a bouncy idle, then give it a try.

FERIOkid

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by conekiller &raquo;</TD></TR><TR><TD CLASS="quote">


Vaccuum leaks won't cause surging.</TD></TR></TABLE>

wow is all i have to say to this one, think before you speak.

As far as the jumpy idle you might want to check your vtec wires because when i changed my ecu in my minime swap i had a bad ground with the vtec wire and the car ran like absolute ****, bouncy idle, to much fuel ect. ect. Try folowing those wires back and make sure they are all secure. Thats the only info i can give you from my first hand knowledge

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">

Nope, sorry - I've adjusted my valves every 30k since I've had the car and it does this every time. The idle doesn't just start bouncing around upon start up - it happens when the engine is cold, you drive a short length and come to a stop - that is when the bouncing begins.

I'm not saying that the ECU has no clue on how to idle the engine - it certainly does not need to learn in that sense. However, there are ECU's that need to go through an idle re-learn procedure. It exists - don't doubt it. Its to compensate for load & temp - things like that.

It may not exist on Honda ECU's - so what? There is absolutely NO harm in promoting the idea that IF you disconnect the battery and IF you all of a sudden get a bouncy idle, then give it a try.</TD></TR></TABLE>

I come to Honda-tech to discuss issues with Hondas, not Berretta or any other makes of cars. I never said that no ECU out there needs to learn, just that a Honda should not need any time to correct issues with idle. This discussion is going no where.

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">I come to Honda-tech to discuss issues with Hondas, not Berretta or any other makes of cars. I never said that no ECU out there needs to learn, just that a Honda should not need any time to correct issues with idle. This discussion is going no where.</TD></TR></TABLE>

Yeah, I come here to talk about Honda's as well. Who is discussing a Beretta? I never said that because my old Beretta used it, that all Hondas do - but a MAP based EFI system is a MAP based EFI system - some techniques carry over through the years. Is this one of them? It 'seems' to be.

You note how some ECU's may actually use this re-learn technique yet exclude the notion that Honda might use it? I guess I see why the discussion isn't going far.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">

Yeah, I come here to talk about Honda's as well. Who is discussing a Beretta? I never said that because my old Beretta used it, that all Hondas do - but a MAP based EFI system is a MAP based EFI system - some techniques carry over through the years. Is this one of them? It 'seems' to be.

You note how some ECU's may actually use this re-learn technique yet exclude the notion that Honda might use it? I guess I see why the discussion isn't going far.</TD></TR></TABLE>

The relearning process I am speaking of are the long term fuel adjustments the ECU makes to obtain "optimal" gas mileage. I am not referring to its abiltiy, or lack-there-of, to learn how to idle the car. Is it clear now?

LSegHatchy

ok first off arent we here to help this guy out if your gunna bicker do it over pm....

To answer your question ... i have never heard of fuel pump causing this problem all though i would not 100% rule this out just yet .....

Double check ALL your vacuum lines.... also take im and throttle body cleaner and spray it lightly around the base of the manifold where it attaches to the head ... if you have a leak it will bog the engine when the cleaner comes in contact with it ..... other than that man ..... i dont really know ... Good Luck

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">The relearning process I am speaking of are the long term fuel adjustments the ECU makes to obtain "optimal" gas mileage.I'm not referring to its abiltiy, or lack-there-of, to learn how to idle the car. Is it clear now?</TD></TR></TABLE>

Yeah - remember how I agreed with that part along time ago? You mentioned how its the 'only' thing that the ECU ever needs to learn and that was the part where we began discussing the bit about idle re-learn which was my initial suggestion to the poster - reset the ECU and let the car warm-up.

JDM_SOHC

So do you think the reason i'm having the rough idle is because of something fuel wise..??? I've checked everything else i could think of....