Hey guys i recently bought an 2000 si with 50,000 miles on it . when i first bought it nothing seemed wrong and it would run fine. i'm very new to these cars and dont know a whole lot about them. the problem happend about a month ago and i cant stand it anymore so i need some help trying to diaignos the problem. It normally starts when i'm sitting at a stop light, my rpms will sit at about 1600 or so and when i slightly touch the guys it starts to bounce. while driving its really really jerky with just the lightest touch of the throttle weather it be accelartaing or letting off the gas ! but when i turn off my engine and turn it back on it'll stop for a lil while and sometimes it'll come back and sometimes it wont. i've read a few posts about people having this problem with SI's and they say its IACV or Fast idle !?!? and for some reason the posts dont end with a solution. if anyone knows which it is or had this problem and fixed it please let me know !! thanx

 

i had a simliar problem, and never got an answer. It seems to have stopped for now, but the idle is still shitty. Bump for you

 

Is the car stock? If not what bolt-on's are done to it?

 

i have a similar problem as well

 

i know .. everytime i read a post and think i'm getting somewhere they just stop ... but yes for the most part the car is stock ... it only has short ram intake !!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JM_Vtec &raquo;</TD></TR><TR><TD CLASS="quote"> when i slightly touch the guys it starts to bounce.</TD></TR></TABLE>

not cool.. lol anyway...

so you come to a stop on a warm motor and the rpms bounce.. could be a whole mess of reasons.. does the rpm ever bounce when you arent touching the gas? it sounds like you have an iac problem which i know you are aware of.. is your car throwing any codes? 14 is iac (reminder) to clean iac just take it off spray the expletive out of it with carb cleaner make that lil screen metal looking again. make sure the o ring is good. (you cant take the screen out so dont try) put back on adn if it still happens check the connectivity of the wires of the plug and the ecu. (using voltmeter check resistance (in ohlms (greek symbol omega on the voltmeter)) resistance should read 0 ohlms if the wire has NO breaks in it. it will settle to 0 so be patient.. should take afew seconds. Make sure the iac is also getting proper voltage. but non connectivity in the wires would result in a CEL unless the previous owner disabled the CEL. quick check for that would be to unplug the IAC and start the car CEL should of course be on then.

If there is no luck with the IAC try to burp your coolant.. a bubble in the coolant can cause idle problems and problems like the ones you are experiencing.

TO fix FITV you should be able to find it in the archived H-T searches. It's pretty basic nothing to bad

need more help feel free to pm

 

thanx alot man !! i'll def try and clean out my iac .... and yes it happens when the engine is warm and it only happens everyonce in awhile sometimes it'll go a few days without doing it and some weeks it'll do it everyday !! the weird thing is as soon as i turn off the engine and turn it back on it'll go away for a lil while and somtimes it'll come back and sometimes it wont . but thanx for all your help !! i'll def give it a try and i'll post the results !!

 

Its your IACV for sure dude. sometimes that problem can be caused by a bad TPS (throttle body sensor). but what you describe to me sounds like a bad IACV. Before you go and replace the sensor (which is located on the backside of the intake manifold, facing the fire wall) i would go to a NAPA or any close autoparts store, and get some 3M Throttle Body cleaner. some people will tell you to get brake cleaner, DONT. Brake cleaner will deteriorate the insides of the throttle body. get a specific throttle body cleaner, and turn the car on and have someone help you keep the car reved at a higher RPM, that way the car doesnt die on you. and just spray the 3m directly into the manifold through the throttle body. if this doesnt work... take the IACV off, by disconnecting the coolant hoses under-neath it and the two bolt on top... and filter some 3m or a simple green degreaser through it and clean it out. Give it about 20 minutes to dry out before re-installing it. Disconnect your batter to reset your cel sensor. If that doesnt fix the problem, then you are going to have to buy a new IACV, which will run you about 130 new from HONDA, or about 40-50 bux used from someone else. Hope it all works out good for you man. lemme know how it goes. later.

 

ohh yea ... and yes last time one of my friends checked the code it was some kind of idle code !! i cant quite member but i'll have someone check it again next time i'm around my friends

 

On mine, the code is an evap code, but the symptoms are very similar

 

evap system will not make ur car run any differently...it has to do with emissions

 

If it's happening when driving, it's more likely your TPS as opposed to the IDLE air control valve or fast IDLE valve.
Or maybe not.

What's the code?

 

Regarding your RPM fluctuating, it might be the ECU. Are you running a stock P2T for your EM1 or something else? My EM1 had a P06 chipped for DOHC VTEC when I bought it. The RPM was "bouncy" too, exactly like how you described your RPM. I switched my P06 for a P2T and it idle perfectly.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Screwtape Sr. &raquo;</TD></TR><TR><TD CLASS="quote">If it's happening when driving, it's more likely your TPS as opposed to the IDLE air control valve or fast IDLE valve.
Or maybe not.</TD></TR></TABLE>

Its true that while the car is running it is common that the tps creates irregular idles however from what it sounds like the car has trouble adjusting to the amount of air being allowed into the engine because of the iac valve. at part open throttle and mostlikely from 2-3krpm a rpm bounce has been known to be caused by an iac not functioning properly. ive had similiar problems like this one that also had a cel for the iac on. turned out to be a burnt out driver in that ecu and crossed wires in my harness. fixed both problems and car runs fine

 

on my car something similiar happened the idle would bounce up and down and couldn't figure it out.. one day i looked behind the intake manifold and the cruise control vacuum hose wasn't on all the way on the back of the intake manifold...and it has stopped ever since......

 

Its your IACV for sure... the bouncing should occur between 1k-2-2.5k and as soon as it hits 2k rpms it will kind of shoot up real fast in rpm... almost like its stuck bouncing between 1-2. im 99% sure its your IACV. the 99-00 si are notorious for this problem. clean your IACV or replace it and watch ur problems go away. lemme know how it goes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ohbebe75 &raquo;</TD></TR><TR><TD CLASS="quote">Its your IACV for sure... </TD></TR></TABLE>

oh its never for sure.. although i brought it up first and am pretty sure its caused by the iac not functioning properly. we still cannot rule out a whole mess of other possibilities. that is simply the one that should be checked.. fir.. well second.. first would be vaccum leaks.. a vaccum leak would produce a simliar problem.. when the iac is not functioning its letting in too much air because the iac cannot see how much air is actually needed by the engine.. then the engine sees this sudden increase in rpms and cuts the fuel to the injectors then once the rpms drop to a reasonable range for the %throttle opening the injectors fire again and then the rpms shoot up .. hence the bouncing... so if the iac is letting in too much air.. that would be almost equivalent to having a vaccum leak.

a good way to check for a leak is to cover the tb but NOT WITH YOUR HAND.. get something large and flat to cover it with that has no chance of getting sucked into the tb and something that isnt your hand.. it doestn feel nice... if the tb is covered and the motor is still running then you have a leak.. all air induction should be coming through the tb and with thta closed off the motor should die within a few cycles... but careful of your hands or whatever u use to do this with..

 

what ohbebe said is exactly what mine does !! once it hits past 2000 rpms it kinda shoots up ... and i can hold the rpms just fine past 2000 rpms !!! and it only happens every now and then and its crazy as soon as i posted something about it to help me figure it out it hasnt came back ... YET !! lol but i've been really busy with work and school so i'm hoping sometime tomorrow i can get to it ... what kind of cleaner do you guys recommend ?!? thanx again for everyones help !!

 

what should i use to to cover the tb with !?? lol anybody try it and found something that is safe to try and cover it with ?

 

i used a big a platics plate from the kitchen

 

If this is anything like my gf's 00 si, it will idle a little high, and if you barely put pressure on the gas, the rpm's will begin to jump up and down by about 3-400rpm... but really violently.

The other symptom is stupid-jerky throttle responce. The car will not allow level throttle control. It either shuts throttle or opens it. It feels almost like an on-off switch.

I have heard iacv and fast idle. her car is not throwing either code, and a friend said both are clean and fine.

I recently heard vacuum leak and either throttle body gasket or intake manifold gasket. I have not had time to look into these.

I am hoping that someone on here has had this problem and actually fixed it. I am at my wit's end with it.

Any thoughts??

 

throttle body gasket ( or other vac leak) FTW! my old EG did the EXACT same thing.. it was pretty violent actually.. it would thrash the engine around a ****.. tore a mount

anyway.. make sure the TB is tight.. if not replace the gasket.... check for other vac leaks

the car also might be making a high pitched whistle noise?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by claytonsmith &raquo;</TD></TR><TR><TD CLASS="quote">throttle body gasket ( or other vac leak) FTW! my old EG did the EXACT same thing.. it was pretty violent actually.. it would thrash the engine around a ****.. tore a mount

anyway.. make sure the TB is tight.. if not replace the gasket.... check for other vac leaks

the car also might be making a high pitched whistle noise?</TD></TR></TABLE>

Yeah... as a matter of fact, sometimes it will whistle a little... usually right after you shift and get back onto the gas....

 

yep TB gasket that **** took me like 2 weeks to figure out.. i cleaned EVERY damn idle valve and everything.. turned out to be a $10 gasket

get one from the dealer for $10.. or make one out of a beer box

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by claytonsmith &raquo;</TD></TR><TR><TD CLASS="quote">yep TB gasket that **** took me like 2 weeks to figure out.. i cleaned EVERY damn idle valve and everything.. turned out to be a $10 gasket

get one from the dealer for $10.. or make one out of a beer box </TD></TR></TABLE>

Thanks... she is working tonight, so no light when she gets home.

BUT... tomorrow she has the morning off, so I am going to use daylight to check all of the vacuum lines *if I can get an accurate diagram of all of them* and I am going to call my friend at a local parts store and see if a tb gasket can fall off the shelf and into my pocket.

Hit you on pm.