- This topic has 10 replies, 6 voices, and was last updated 8 years, 9 months ago by
.
-
Topic
-
I’m in need of help. I have a 94 accord with and (i guess) common surging idle. I replaced the IAC and clean as much as I could of the intake. I pretty sure there is no air in the cooling system. When I cover the lower port on the throttle body, the car idles normal. Same thing happens when I cover the upper port. Now when I cover both ports the car almost dies, but keeps running. Edit: The car does not die when both ports are covered
This problem started when I developed a leak in my old radiator. This happened while I was away so I had no choose but to drive it home with the leak.
Sometimes when the car is warmed up, the surging isn’t as bad (1500-2000). Other times its (2000-3000).Right now I’m at a lost. I tried everything I can with limited tool and limited knowledge.
Any help would be grateful. Thanks.
-
Replies
-
Here is ETCG Idle speech that may help you –
Idle speech
There are a lot of things that can contribute to an idle issue, in fact in the end it may still be there to some degree because of the nature of that engine however here are some things to start with.
First start with a good tune up, use NGK or Nippon Denso plugs, don’t change the wires if they are OE, if they aren’t OE you might consider NGK wires as they are very good and less expensive then OE. A quality cap and rotor should be good. A new air filter also helps.
Don’t change the PCV valve, if you see an aftermarket PCV valve in there put a Honda in, believe it or not I’ve seen idle issues caused by aftermarket PCV valves, the OE’s last just about forever so you can easily justify the expense.
Next a good valve adjustment, this goes a long way to smooth out the idle if done correctly, mess it up and things can get a lot worse though.
While you have the valve cover off check the timing belt tension, if you feel a lot of slack this can cause the cam to ‘chunk’ as it spins causing a rough idle. If you think the belt has been on there for some time then you might consider changing it and resetting the tension properly, if it’s not ready for replacement you can reset the tension to take up the slack.
DO NOT adjust the idle screw under any circumstances, it is set at the factory and that is the reason it was sealed in the first place. If you find that the seal has been broken and you have a low idle and you have done all of the above then you might turn the screw out a little to see if that helps the idle but only enough to try and bring it back to where it was before it was adjusted in the first place.
Last clean the screen in the Idle Air Control valve, this can get clogged up with carbon over time and cause the flow through it to be restricted which can cause idle issues.
If you still have a ‘rough’ idle after all of this THEN look to the engine mounts as you want to be sure the engine is running correctly before you go for those as the one in the back is a real pain to replace.
http://www.youtube.com/watch?v=L788jKEVblY will also help C8-)
Have you reset the ECU by unplugging the battery for a few minutes? It sounds like the engine is ‘hunting’. This could be Electronic or Mechanical.
Unplug the battery for a few minutes. Then restart and let idle a few times for it to ‘re-learn’ where it needs to be.
Next to try would be the Fast Idle Thermal valve. It is another one of those common Honda valves that needs to be cleaned and tightened (plastic housing supporting valve seat inside.) Commonly referred to as FITV. Eric has a video on where it is, how to clean, and how tight to adjust.
A long shot would be your TPS or Throttle Position Sensor. If it is not giving the ECU a good reading of the plate in closed position, then it would tell the computer to compensate (causing a hunt cycle) when not necessary.
I read the idle speech. I’ll check the plugs and PCV, but I can’t do a valve adjustment.
I watched that video along with the coolant video. I have a new IACV and the FITV seems good.
I researched the re-learning steps, but everyone has different instructions. I tried one, but it didnt help.
Sovled!!!
FITV was clogged.
I removed it, cleaned it with TB clean and seafoam. Let dry then reinstall.
It idles normal now, but when I’m coasting it still hunts. Going from 1000-1500. I’m guessing its has to relearn now that its unclogged.Also, I installed a new IACV, should i keep it or reinstall the old one. It cost me about $150. (someone xmas gift is sitting on my TB)
Thanks for the help.
If it has been installed, then likely you won’t be able to return it. However, if you can and your old one has been cleaned, by all means return it.
Eric has stated in a video that he normally replaces that part rather than cleaning it, but only because his experience at a dealership. Dealers make money on installing new parts more than cleaning old ones. If the part is returnable, go for it.
Quoted From TejasNW:
If it has been installed, then likely you won’t be able to return it. However, if you can and your old one has been cleaned, by all means return it.
Eric has stated in a video that he normally replaces that part rather than cleaning it, but only because his experience at a dealership. Dealers make money on installing new parts more than cleaning old ones. If the part is returnable, go for it.
That’s not the entire reason actually as I really haven’t known cleaning those valves to do much good, in fact if you just do a quick search of this site using the search function for ‘Honda Idle’ I’m sure you will see many instances where people have tried to clean those valves and still had the same problem till they replaced the.
I know that you state this problem was solved but the fact that the idle is still hunting would indicate otherwise. It does sound like you’re getting too much air and I don’t recall you mentioning that you checked for vacuum leaks. In addition since you ‘messed with’ the FITV and it got better this might be the culprit all along, at the very least you might want to check it to see if it’s loose but be warned and I recommend watching that video response to my idle video to get an idea of how that valve is suppose to work or better yet how it WON’T work on cold start up if you turn it in all the way.
I have a ’94 Accord, it also surges at idle, Something else though. When I push on the brake peddle, All of the lights either turn off, or get really dim. The electrical latch the would release the shifter also won’t work. This tells me I have an electronic issue somewhere. I am not very familiar with Hondas, So I am a bit out of my element. Any ideas to help me with this are great appreciated.
I was coming home in my 95 Odyssey last Sunday night as I hit a metal expansion joint on a Bridge doing 60mph a loud shaking and bang scared the :woohoo: out of me. Not wanting to stop on this bridge I slowed down and put on the 4 ways and limped to other side where I pulled over where it was safer. It seemed to me OK as the noise wasn’t as bad so I was 2 miles from home I decided to limp on. I got close to home and it started to make a worse grinding sound so I stopped and called AAA for a tow. The driver looked under the hood with his light and told me it was my rad fan, it had 2 blades left and the shroud was broken as well. With the fan disconnected I sailed home 😆 . I picked up a new fan unit at the Wreckers and once I put new felt on the sides I will get it put in.
I drove a 100 miles on the highway to get the new fan and had no problems, kept the heat on except one time today it went up a little and I got out of the traffic jam I was in and got the heat on and it came back to normal temp fast. I did have a brief idle surging when I parked it but when it was cooled a bit it was fine.
I must have had some debris fly up and knock the fan out, I thought at first it was because it was loose. I am missing the splash guard.
- You must be logged in to reply to this topic.