8 years later and this is still the Go to video for all service techs dealing with old ass Honda's.. Truly a testament to scanner Danners knowledge and his journey to the answers.
In my country the bigest problem is a lack of knowledge, a lack of information, without desire for learning....that's why most of professional mechanics are part changers
Thanks for the tip. I think as long as the engine doesn't stall or give you any driveability issues when cold, then do we really care if the cold fast idle isn't to spec? As long as it is not too high of an RPM then I really don't care at all. If it is a paying customers car, let them know what you did and any future issues that the valve will need to be replaced. I still like the fix. Thanks again
as soon as you figured out the the cold-fast idle valve was open and you could thread it in I was yelling at my screen saying, "YES! YES! That;s it dude!!" that issue was killing me and I went and did the exact same thing you did! right on brother. thanks for your videos
Thank you, Mr. Danner, for making this video it came to a huge help to me just yesterday dealing with excessive idle problems with my Honda after adjusting the fast idle valve the idle problem has gone away completely. Thank you.
I’m thinking of just deleting the fast idle valve on my Acura cl. I always warm my engine a bit before I drive it and I feel like it would be better to not have 2k rpm on a cold engine and I just want it to idle low weather it’s hot or cold. Does that sound like a good/bad idea?
on a MAP engine there really isn't un-metered air like you would have on a MAF engine. This IAC leak is exactly what a vacuum leak would be on this design. so, yes, in a sense, it is a vacuum leak
ScannerDanner hi i have this same problem with my honda civic 2001. I dont have the part that u tightend with the screw, i took out the tb but dont have that ??? Thanks
Ya my friend had the same problem on his 93 integra and I adjusted it n BAM ran fine I think that's crazy. I'm guessing over the years it gradually loosens up then it starts rev high
For sure man, and I truly value your input on this. I am still not convinced that this seat didn't work its way loose on this one, but not sure if I will know for sure until I see more of them. And this is a dying system, so I don't expect too many more. For anyone else reading this, be careful with this "fix" and please understand the variables here.
my husband bought a 97 dodge neon with the same thing it surged he sent it to a garage and they wanted to charge $2000.00 to rebuild the motor we took the car back he went to check the air filter and found the massive air flow boot was split on the underside he changed it the car ran perfect so that shows how much garages try to scew ppl
This fix worked for me. Turned out my diaphragm was backed almost completely out in the valve. Was difficult to screw in. Used a quarter instead of a flat head. Worked great
2000 crv surging idle. Don't buy any parts. I know what it is. Take off the big air hose, now see a small water hose going from near the upper rad hose where it connects to the engine. Follow that hose up and around to a connection on the throttle body. From there the water is supposed run through the fast idle thermal solenoid (that first cap, then through another hose to the IAC motor, then return to the cooling system. Short explanation, that water system is plugged up, which never allows the fast idle thermal solenoid to close and the computer tries to compensate with the IAC. Can't do it, so it goes into an oscillation. OK, so now you kinda know how it works. Take the whole throttle body off; it's easy, two bolts, two nuts, two little hoses, two electrical connections. Take off the parts that the water runs through and clear each part with drill bits, scrapers, or whatever you have. Clean everything up so you can blow air through it. Cap, fast air solenoid, must be removed and cleaned out including the water passage in the throttle body. Put it all back together and enjoy the car running like new.
:-) After I shot this video, I did watch one where Eric was adjusting one of these. I don't remember what he said about it or what his setting was. I'll have to watch it again.
I like the comments and feedback! Keep them coming. I looks as though valve replacement would have been the proper fix hear. I will update this in a few months and let you guys know how our "fix" is doing, as this car is owned by one of our students.
@@ScannerDanner I have a 2004 honda jazz, in Australia. The IACV under and attached to the throttle body is water/coolant , magnetic, electronic (it plugs in), the spindle was seized hard. It took 3 days of soaking with carby cleaner, squirts of wd40 and ,eventually, a firm but gentle twist with pliers to start moving the spindle that appears to be magnetically controlled too, (what a pffft idea). So, the engine would idle fine at start up. Once warn/running temperature, the idle would fluctuate between 900 & 3,300. crazy. After repairing the IACV, the idle has been good for about 4 weeks. 1.5 l 5sp manual idle @ 750. well, yesterday the erratic idle restarted. With all the variables of possibilities it could be any of a dozen things. Think I'll start with cold idle valve adjustment. 2nd will be the IACV again (apparently if replacing, it has to be oem or the computer won't recognise it, what a pita). A new part here is over $900, about $550-$650 US depending on the day. Lots of 2nd hand refurbished? parts, don't trust those. It comes to a point when the parts to fix these cars are way more expensive than what the car is worth. It's a shame. When they run well, they are good cars. When they don't, well, bonfire night looks good. Thanks for the in depth analysis you have provided. Hopefully, at some point, this offset idle can be sorted for a reasonable cost. Mechanics here are way too expensive, as in, they want money even if they can't fix it. I don't mind paying labor costs, that's business, but, $1,000 or more for a non repair, supposedly diagnosing with no fix, I'll stick to you tube and try and try again until victory
I had a mechanic replace my idle air control valve and the engine still surges very slightly and the check engine light turns on and off occasionally with that P0507 code. I need to find a good mechanic to try to do this 🤔 but any idea why the code would turn on and off as well?
My dodge ram 1500 was just doing the same thing. I changed the throttle body and it fixed it 90%. The other 10% I think is because it's from the junk yard. But it's no problem at all
that is because most "professional mechanics" don't know with 100% certainty what the problem is. Truthfully there are times when I make a call, that I am not 100% either. I strive to be, I show methods on how to be but we are still human. Think about a doctor and how many times they get it wrong. Why don't we hear the same thing? I'll tell you why, because insurance companies foot the bill. When a doctor makes a bad call how many of us tell the doctor we want our money back?
Adjusting the TPS until idling smootly solved the same problem. Maybe the surface of the TPS's resistor is worn, and needed to be adjusted slightly. It's running for a few days now like a dream. Hope it helps.
Why dont you start your diagnostics with the Keep It Simple method. Checking for vaccum leaks, checking intake lines and your intake manifold gasket for a leak, ive seen the same problem this car is having be caused by leaking injector o rings.. though your computer can save your ass in certain situations, keeping it simple first will save you a lot of time if the problem is something small.
You are a real Pro ! Many "mechanics" these days make fixing cars really troublesome...Thank God for guys like you that are real Pro's and allso are generous with us help seekers and post issue fix videos on RU-vid . God Bless you and Hello from Romania in 2019. I have same issue with 2002 Toyota Yaris 1.0 4cyl vvti engine . will check tomorrow about this control valve.
a vacuum leak on a speed density engine (MAP engine) generally will not cause a lean condition (at least smaller leaks anyway). the reason is the MAP sensors "sees" the manifold psi increase and sends an increasing load signal to the PCM, the PCM in turn provides more fuel. So now you have more air and more fuel = RPM rise! The O2 is really not in play as part of the high idle here. It is a factor but no the main cause of more fuel being added.
Thank you so much for this video, I've tried everything to fix my idle problem, from the pcv to the iac and nothing worked. This video helped me and it was easy to understand. I was able to do it in an hour after watching your video. I appreciate it so much, you've earned another subscriber. Keep up the good work!
close, i didn't say it would be rich. i just said the PCM will add fuel in reaction to MAP voltage increase. If you think about it you have extra air (vacuum leak) and the fuel to go with it. so it balances out in a sense. this is why map engines idle high with vacuum leaks. Section 1 in my eBook under vacuum leak testing I have a good case study on this.
good thought. I would say no on the coast comment. Decel fuel cut-off is a function caused by a rapid closing of the TPS along with a high RPM. So with no TPS activity, I don't see this being the issue. Of course, the main point which we can all agree on is the surge is being caused by injector shut down
good question, I am not 100% sure on all of the inputs that are being "watched" before the ECU decides it doesn't like the idle speed anymore. I know ECT and TPS are involved and also a run timer.
@ScannerDanner great video you’re very educated I love your video, first one I’ve seen but am impressed with the amount of knowledge you give people instead of just summarizing the problem🙏🏼🙌🏻👊🏻
makes sense for sure, so if this is the case with this one, all I did was put a band-aid on it. Do you think the seat could have moved? It turned pretty easy on this one.
One thing that always bothered me on older Hondas is that the TPS is riveted to the throttle body....slightly annoying And yeah, I've ran into this exact scenario a couple of times. Another awesome video Paul
I believe the injector cut is actually just the DFCO logic - if the throttle is closed and the engine speed is above some threshold RPM, it'll stop injecting fuel. It just happens that when the idle is fast enough (say due to a vacuum leak), it'll hit that threshold and start oscillating,
Good question my friend. RTN = return. SIG RTN = signal return, this is another name for a sensor ground. MAF RTN is MAF return. This is a unique design in that there are two grounds. One ground is the PCM MAF signal voltage sensing circuit and the other is a block ground. So the MAF grounds to the block and the PCM MAF sensing circuit grounds through the MAF sensor. (noise prevention is all) Hope that makes sense.
no problem at all my friend. it is still up for debate as to why this method of control is used, but at least we know for sure now what is causing the surging.
You can actually hear it without undoing a bolt, especially with aftermarket air intakes, sounds like a massive vacuum leak! Great video, this should be shared on all those awesome Honda forums.
I drive a 95 honda accord and it just started doing this bullshit. Thanks for the info i just went and checked under my hood for that cold fast idle valve and its there. I know what i gotta do now👍
Thanks for this video, immediately solved my idle problem! I adjusted the valve to the max bottom and left it there. It's probably only temporary fix, but it will do the job until i buy new one.
Thank you for this information. I have an Accord that has been do this since I got it. I purged cooling system, cleaned IAC but all it needed was the FITV adjustment!
Hi Paul, Eric the Car Guy had one of these valves on one of his videos, he screwed it right in then undone it about 1/4 turn and it cured hi..so think you done the right thing...I actually thought to start with when it surged it was slowing down and the IAV was opening it up to keep it running, but you proved it was the other way round..good work - Fred.
ScannerDanner i've had quite a few hondas with this exact same issue, and ive had great success on disassembing the valve and cleaning it out with carb cleaner or brake clean, and reinstalling. after that it worked perfectly everytime with no adjustments required. just for future reference maybe give that a shot.
thanks jerry! i really appreciate the comment. let me know if there is any other lecture video you would like to view again. I'll open it up for you at no cost. BTW as a loyal customer, do you think 45 days is long enough for the streaming videos? i was thinking of increasing it
loving the video, my integra has a surging idle and i think this might be my problem, i had cleaned my idle air control valve and the problem never left so hopefully this can help me tomorrow
Mr Scanner That was a life saver so far. I have a 92 honda accord. And I have a blown head gasket which obviously leads to alot of over heating and coolant leaks. I'm in the process of getting it fixed but recently this idle surge just started happening. I'm wondering if its due to the head gasket and coolant issues? I'm definetely going to do the air test Saturday
Hi, thank you for all your video's help us , I have Toyota corolla 2008 1.8 XLI Japanese made, I have vibrate engine when I put my gear on D or R ( at Traffic stop) RPM = + - 625 ,Iv changed ( torque convertor, gear , plugs , coils , fuel ump , Injectors , ETPS (Throttle) , MAF , EGR, purge valve solenoid ,Intake Air manifold gasket , but useless , no any check engine light . can you help please?
My daughters 95 accord w/4 cyl v-tech has surging idle. I've flushed coolant and checked for vacuum leaks. the car starts fine but within about 5 minutes the idle goes back and forth from 1,000 to 1,200 rpms. While it's doing it if I disconnect the Absolute Pressure Sensor it misses a little then settles down. Nice quick fix but I DON'T LIKE DISCONNECTING THINGS because I don't know what new problem I may create. I want to clean or possibly replace the IAC but the engine is right up against the firewall and very hard to get at. Is there an indication of what may be wrong by unplugging the MAP sensor?
I just bought a 1999 Civic ex with the idle surging and reads the P1509 code. Cleaned the IACV it didn’t do anything and verified it works by testing it. I’m Lost🤦🏻♂️
love your videos scannerdanner, help me learn alot, i hope you read this, those fitvalves are adjustable that brass ring you can turn in or out, i know they have a problem with them working themselves out and causing same symptoms , i did scope test before and after i adjusted the valve in and was a good fix just by adjusting the brass ring in, no need to replace, please get back to me and confirm, ive done on 2 different cars and no problems, without replacement, id id love for you to test this fix100% so i know for future
Just found this video better later than never.I’m having a serious up & down idle on my B20b.changed iacv,fast idle valve,tps,map sensor,ecu and other sensors an the problem is still there..it’s idling from 500rpm up to 3000rpm but wen I block off the lower hole in my throttle body like wat you did the problem goes away how can I fix this problem bcuz I changed the fast idle valve and it still doesn’t help..can you give me some advice on this please your help will be kindly appreciated or any one in the comments please thank you 🙏
Tps at idle position with rpm higher than 2k will kick the deceleration fuel cut, that's how all 80's and 90's Japanese used to work. Any vacuum leak or stuck idke valve will cause that.
I wonder if a lot of country guys can understand the way you explain all this most guys can't afford the modern aqippment and the Hi Tec way you explain it like its a Rocket Ship all due respect
Have a 2005 honda civic which started this idle issue day before. When i block the hole in the throttle body, the idle returns to normal. So I figured it’s a bad idle valve stuck open. Waiting for replacement part
(am not saying that is a vaccum leak) i am saying that this "mimic" a vaccum leak, and is to far to much air for the idle control valve to compensate. i am asking if thecnically this could be considered unmetered air also.not sure if i am getting my point across here. the idle control is set to allow certain amount of air right? if you develop a intake leak the idle control will try to close right ? with that been said "this condition and an intake leak will be considered unmetered air"
Excellent! learned so much here! Thanks Paul! Great explaination and investigation! Its not just hondas, this happened to my suzuki g16b motor from a baleno
Very educational video I learnt a lot from it and me being a Honda enthusiast. Just having a low idle issue on a H series engine that I need to fix. Pretty sure it's the Idle air control valve on the front intake that should be my issue.
IACV. Which dance for idle air control valve. That wasn't the cause of my problem it was just a dirty throttle body. Needed extremely good clean She runs like a dream now. I even made my own video on my own personal experience with this problem. If anyone's interested.😉
I do not understand why do the car have both electronic and mechanical air bypasses for a first rapid thinking only electronic unit can do perfectly the job (according to cooling liquid sensor) isnt it Paul?
ok....when the cold fast idle gets stuck open is like a vacuum leak then, it trows engine lean, o2 detects lean condition and change the injector pulse at idle? so an intake manifold leak will show the exact same simptoms?
that did nothing on my 1995 integra or new manifold gaskets changed all other sensors re soldered the sending box i will never buy another japanise car. all cars now have to many problems.
So why there is a need for MAP sensors on the maniold, on engines with MAF sensors , If MAF meassures exactly the cfm flowing trough the engine why is there a need for a MAP.my engine has both.
ok i correct myself the garages where i live there always looking to make a buck specially if they think you dont know anything about machanics, so sorry there are a few good garages out there
Thank you Professor Paul for this case study, I’m having this problem on my ‘03 Honda Odyssey w/3.5l engine. Following Mitchell1 DIY instructions I don’t get to radiator fan coming on point before my TCS light comes on the dash. Will be diving into your book.
i try many things change many parts for idle issue nothing worked then i ran the fuel down to half tank ran the car and the idle fixed itself i think the problem with honda or acura idle starts with full tank of fuel swishing into or blocking the return pressure fuel line or fuel clogging the venting canister.so never fill your acura over 3/4 tank .
Christopher Elrod did u ever figure it out, same problem mine idles great even when it’s warm, soon as I pump the breaks the surging starts when warmed up.. I have replaced everything from the hoses to the check valve, booster, master cylinder, tps, iacv twice, new temp sensors, new water pump burped the radiator did everything said to do even adjusted the idle and still surges at warm up when I apply the brakes no vacuum leaks new throttle body gasket as well I’m hella stuck
Nope sorry bro, all parts are brand new so dont know wtf the problem is. I just found my jumper to my ECU is fucked up so Im hoping it was a lose wire, should have it installed in a week or two.. Try looking at everything bro from sensors to the plug on the wiring one could be not putting out the right voltage, replace all your hoses to the intake, gasket to throttle body etc.. Ive replaced everything that goes to my engine accept my starter, but Ive had this problem for over 3 yrs now, so the last thing was my harness.. I even ripped out all the brake lines and ran new ones replaced booster master cylinder, check valve so Im stuck at harness (wiring) possibly
Have the same surging issue but on a Mazda B2200 1993. Pretty much did what you did here except you can adjust the IACV without taking anything apart by just adjusting a screw on the outside, it runs so much smoother now. I have been trying to fix this surging issue for almost a month now and my next step was a new IACV which runs between $300-$500 new. Thanks for the video!
I took IAC sensor from the valve and their was a o-ring that came out that pretty loose in the IAC it pretty big to fit on bottom of valve were it meets sensor , what is it for
