idle issue
949
Senior Wagonist
my idle keep bouncing and then it stalls out after a while. i dont want to have to keep my idle really high just so it doesnt stall out.
anyone know what it could be.
anyone know what it could be.
Comments
The quick easy way to check for a vacuum leak is to spray some carb or brake cleaner wherever it could be leaking (intake manifold gasket,vacuum lines,etc) and if the idle changes when you spray at a certain spot that is where the leak it.
i agree with you guys, it does seem like a vacuum leak because its all working parts. it was idleing fine when i took the engine out. i would assume that all the parts wouldnt just not work by having it sitting there while the engine is being worked on.
what does FITV stand for?
ill try to clean it. out as for what they call it its different from everywhere i look. i downloaded a free shop manual and they call it the EACV.
basically i just understand it as the idle control valve.
anywhoo...
why does spraying cleaner on the leak make the idle change. please explain more.
as eldonciv777 said "check the sensor on the intake manifold that has coolant lines running to it. It has a little valve inside "
what does the valve look like?
does it come out?
fond this site.
http://www.team-integra.net/sections/ar ... cleID=1174
i guess this could help.
not sure if i can spary brake cleaner all over and in all the holes?
will it damage any sensors in there?
i know the site says too but i know brake cleaner is pretty strong stuff and sensors are usually known to be sensative.
I forgot you just changed your engine. In that case I would bet my life it's a vacuum leak. Spraying brake cleaner won't hurt a thing and it will evaporate at a very high rate. It changes your idle because it is also flammable and when you spray it on the vacuum leak it gets sucked into the intake and burnt. Its not flammable enough to start on fire upon contact with the motor though, so no need to worry about that. You can also listen/feel for the leak if it is large enough.
Look 2 places for leaks:1. Intake manifold gasket if you removed your intake manifold during this swap and 2. You forgot to put a line on somewhere.
This could be sensor related but if you used your same manifold on both engines this is very, very unlikely. So ignore all that crap until you rule out a vacuum leak.
if i unplug the green wire, do i just plug it right back again with the engine still running?
i am also thinking maybe the iacv gasket might need to be replaced. i guess if i spay it with cleaner then it should tell me if there is a leak. if it is a bad gasket on there because when i took it off, it looked kinda flat and no longer a round. the gasket that looks like an "8" behind the iacv.
do they even sell the iacv "gasket" by itself?
I was just saying you can tell if its the IACV if your idle normals out when you unplug it. You are going to have to reset the ECU after you plug it in. What you need to do when you plug it back in is:
1. Car needs to be off.
2. Re-install plug
3. Remove your Hazard Lights fuse from the main fuse box under the hood for 30 secs or so, then replace (This resets the ECU and any CEL codes)
4. Start car and CEL should be off.
When I have this problem it usually happens after a motor swap. My theory is because the IACV dries out and just kills it. When its operational it has coolant in it. I usually pick a couple up at the junkyard every time I go. I'm pretty sure they are the same for DPFI and MPFI but I could be wrong.
Oh oops! Yes you can just plug it back it in with the car running but the ECU will be in safe mode so you need to reset the computer anyways.
sidenote: I've heard that is best to reset your ECU when you switch to different grades of fuel and after oil changes because the ECU will change slighty to adjust to different conditions. A sort of optimization that is built in.
nice, i didnt know that.
so far what i have done was i took off the IACV and the FITV.
I took some brake cleaner and have been just cleaning them out.
also i noticed the O'rings that mate the two to the intake manifold seems like flat. so i am attempting to replace those.
the one that is on the IACV is like a figure "8". that seems kinda specialized so i ordered it from a honda dealership. it will be there by tomorrow.
they have discontinued the one on the FITV but it looks just like a regular round "O" ring so ill go pick one up at a local homedepot or autozone. im thinking autozone or kragen is my best bet because the rings might be more tempered for the higher heat.
nope
how?
when i forgot to replug it back to the harness wire, i got a cel.
what did you do?
after i took out the engine to work on it, i put back everything and ever since it just wont idle correctly.
i checked the IACV and FITV.
i cleaned them out with brake cleaner.
i tested the IACV to hear if it will click. there is a motor which just opens and closes it.
i cleaned out the FITV with brake cleaner as well.
still nothing
recently i sprayed the pcv valve
the same one that is connected to the oil breather chamber.
it did seem to make a small difference but later during the day after driving a few hours it did it again.
i dont want to just repalce all these parts since the parts are super expensive for what they are. i dont mind replacing them with new parts but i only want to replace what is needed for now.
so i am lost, what do i do now?
i was looking around youtube and i found one video of my exact problem but on another car.
it looks like this one.
http://youtube.com/watch?v=bH6bf3kZiZU&feature=related
one of the post on there says this:
To assess the rollercoaster(up and down) idle problem you have to find out two things.
Does it idle up and down when the engine is cold?
Does it idle up and down when the engine is warm?
If it only does it when the engine is cold (first started) then the idle air control valve needs to be replaced (NOT CLEANED) Cleaning does little and it most likely a "temporary fix".
If it does it when it's warm as well you have one of the two problems.
1. A bad MAP sensor.
2. A bad TPS sensor.
mine is when its warmed up.
i also found another place that said to test the tps all i have to do is unplug the tps harness. if it idles out fine then thats your broken part.
...mine now idles fine with out the plug. now your thinking why not just leave the plug off and keep driving.
i dont recommend that because with out the plug hooked up, the car will eat up your gas in no time.
i justed gas up, the car has been only driven around town about 98 miles. the rest is sitting there idling so i can diagnose it. i am almost empty in gas.
when the tps sensor is unplugged the ecu goes into limp mode and just dumps a whole ton of fuel all the time into the engine. so even at idle it thinks im at wot. the plug tells the ecu how much fuel to give the engine at what ever the position the throttle is at.
so i am searching for a new tps but there are so many versions. and the dealership does not sell these by themselves. they sell them with a brand new throttle body. which is pretty expensive.
if you ever need to replace yours here a great video that will teach you how to put one back on and recalibrate it.
the video is for a brand new throttle body install but it also shows how to take off and reinstall the tps sensor.
http://youtube.com/watch?v=ukPoe5E4Fqg&feature=related
dr. charles uses the OHM method and not the volt method to reinstall the tps. mine is obviously messed up, so i dont trust the reading right now.
if anyone has a manual book and can tell me the ohm i would totally appreciate it.
or if someone has a mutlimeter and can just unplug the harness and test what the ohm is with the engine off. that works great.
make sure that you have the same car i do cause i dont know if the readings are the same with other versions of the car.
i have the 1991 4wd wagon d16a6.
also this needs to be a stock throttle body and stock tps.
if your not sure how to test it or what i am talking about just watch the video with DR. charles from skunk2.
thanks.
i hope this will help others find their idle issues too.
i also changed out the pcv valve too. that help a ton.
very cheap. at kragen its only 5 bucks. if your car is old you should just change the parts to new and not try to brake cleaner it out. its just a temp fix and it can come back.
it only does it after its kinda warmed up.
at this point im thinking its either the maps sensor or something else.
anyone know how to test the map sensor?
Also, on your IACV there is a screen inside that you can clean out that sometimes gets clogged. If that area s leaking, just use Hondabond and reseal it up.
basically before i get into that here is what has been done so far.
ever since i put the engine back together the idle happened. before it all the parts worked and nothing was broken. the idle was just perfect before i removed the engine.
symptoms, the idle will be kinda higher then normal. when i adjust it, it will bounce and roller coaster up and down. then eventually it stalls out. i can restart but it will do it again. the roller coaster only happends after it either warms up or i gas it a little and release it.
i removed the aicv and cleaned it with brake cleaner. cleaned it out the metal screen. replanced the o ring in there so it will have a new secure fit.
tested the aicv with the cars battery, placed it on there and the little motor moved. not sure how much its supposed to have moved but it did. so i assume that it is working properly.
i removed and cleaned the fitv. also replaced the o ring to just to make sure it is ok.
nothing here to test out really. or at least i know of.
i then checked to see if there is any leak. i used the brake cleaner can and spraying generously around connections and parts that mated up to anything that was linked to the intake manifold. as far as i know i am supposed to look for things like fluctuation of the idle. i saw nothing change. im not sure if im spraying at all the correct places so it might not be the best test.
then i replaced the pcv valve. that did make a small change. but after a run on the road the symptoms came back but a little less.
its a pcv valve from kragen.
then i was told to test the tps sensor by removing the plug. if the idle was stable then its the tps sensor. it did stable out. so i thought its the tps.
i bought a blox tps sensor from ebay. i put it in. i just calibrated it. the idle now just drops. after i start it up it will idle low like how i like it then after i gas it, it just stalls out. if i drive and try to keep it up by feathering the gas it will just stall out. sometimes it keeps it level for a few sec but it will stall out again.
so now im lost. i thought if there is a lose hose the idle will just jump up. but the idle just stall out. its stalls out too early that the bouncing doesnt have time to react. so what does that mean?
I'm not having exactly the issues you are/were, but I'm getting erratic ECM 7 codes and they reset on key-off. simple fix but they're getting more frequent.
also the mileage doesn't seem to suffer while the code is active. still in the 40+ mpg range, hiway.
AFAIK, stock ECM, throttle body and TPS. just researching and found your thread.
thanks,
...jm.
but so far since i have posted on this thread.
-adjusted cam lash, set it to 6 in 8 out.
-readjusted idle screw
-readjusted dizzy, advanced it
with all these adjustements it kinda helped but didnt fix the problem.
i do have an idea what it is. it will be fixed within a couple more months.
Recently my wagon has been showing signs of the same sort of problem starting up. I may reassemble the spare dizzy that came with the CRX's replacement motor and try swapping that on. That's the great thing about having 2 cars with exactly the same motor and spare parts for both. 8)
lots of good info! thanks guys, mine is when it is cold...
bowz