seoul4korea

Well Gents Heres the basic's

Honda Civic 2005
1.7L SOHC
only thing I have done to it is Plat +4 spark plugs and a Drop in K&N filter.
60,000 Miles.

The Problem:
There are times (that happen more often then i'd like) where the car will Slowly start dropping RPM's. This rate is consistant and will drop all the way till the motor dies. While it is in the condition any Attempt to change the throttle has no effect and the car will continue to slow down.

Things i've tried:
I've tried scanning it about 100 times and have yet to get a code..... This includes taking it to a shop and having the codes run.... Zero showed. I've also had the same shop check all of the connections and for loose grounds. I've ruled out the fuel filter due to the fact it is a life time drop in filter that is apart of the pump.

other thoughts:
When engine runs there seems to be no problems, I still recieve zero codes. No crazy idol and no jerking, all and all everything seems perfect. 02 sensors are new and I haven't really had any problems. I just got done driving it from across country so I figured being that it's OBD-II maybe I need to reset the computer.... Idea on that is that OBD-II will learn a set of driving conditions and repeat it over and over when it goes into closed loop. The issue with that is that before the 02 sensors warm up to the 600+ degrees that require for closed loop it will shut down. If anyone can help with an idea or knows someone that has had this happen to them please let me know!!

seoul4korea

Also I Thought maybe it could be a Loose TPS or maybe The spark plugs but I'm not sure But I think that Plat +4 don't require to be gapped. Should I Swap out the plugs?

unTuned

that is correct. they should not need to be gapped. did you gap them?

seoul4korea

Nope of course not just making sure lol

unTuned

well from a lot of discussion on here, ive pretty much concluded that the best plugs for our car are the iridums. i just put some new ones in a few weeks ago and it runs beautifully crisp. NGK Iridium IX are the plugs and they run about 10-12$ per plug. if you have platinums and theyre still pretty new, you know that the plugs are not the problem so dont go out and buy others. an easy 5 minute check you can do though is to make sure theyre snugged in and not loose at all. if you have one thats even a little loose you can start to run into problems. its worth a try to see if it helps, especially since its easy to do and takes no time. just pop off the valve cover, undo the bolts and just check to make sure they are in there tight.

also, a bit more info if you can. does the car do this while its idle with no throttle as well? i seen you say it does it as youre driving, and will eventually drop rpms until the engine dies (im guessing you would be coasting to a stop unless you were able to start it again?)

seoul4korea

The spark plugs are about a year old now. I can take alook at them. If there was a loose spark plug wouldn't it throw a code for having like a lean burn or some thing like a misfire? Yes the car only dies when in motion. I've had it happen to me at which point I would be coasting. There was one time where I caught it right when it started and I killed the ignition put it in neutral and TRIED to start it agian. When it happen it wouldn't start again. I did have Full power to every thing else and I could hear the fuel pump pressurize but the car wouldn't turn over. and some times you can hear it trying to turn over. Both the battery and the Alt have been tested as good. after WAITING for like 5mins on the side of the road you can start the motor again no problems.

unTuned

that sounds annoying. when you check for an error...if everything at that particular time is running fine, it wont show the error. that doesnt mean that everything is always running fine though. the plug check would be a good start.

my next suggestion was to check your fuel pump, but if you know your fuel pump definitely has no problems...the next check i would do is on your injectors if youre able to. are they stock? have you ever had any problems with them?

seoul4korea

Everything on this car is stock other then the listed items before. I've run scans like a hundred times while parked, while driving, all the time. I had a code for this. I did have one in Vegas for a faulty 02 but I changed that. The injectors are stock everything is pretty much. Besides injectors are hook to the ECU so that would throw a code. hmmmmm

unTuned

damn im out of ideas. those are the things i would check for thatproblem. someone will suggest something though.

BlueEM2

iTrader: (1)

Start by cleaning your throttle body and sensors. This is most likely the problem and should be done as regular maintenance every so often. Take your throttle body apart and clean it out with a good throttle body cleaner until all the crap is gone and make sure to pull all the sensors and valves outta there and spray the crap out of them too. You will be suprised at how much crap gets in there over time.

If the problem persists check your head gasket. It also causes those symptoms. Check to see if you have white smoke coming from the exhaust.

Hope this helps, good luck.

seoul4korea

Tomorrow I will be removing the Throttle body and cleaning sensors. As for the head gasket I'm sure it's not that because I don't have any smoke and I haven't been losing radiator fluid. Hopefully I can ge this to work!

Running Riot

Is it possible for you to get your hands on another ecu? I had a problem similar but not exactly to this. I would get a wierd lope at idle and an IACV code. Swapped out the ECU problem hasn't come back. A code won't come up for it since the ecu is bad.

If not, what does your valve train sound like? Is it very noisy? My valves were looser than a las vegas hooker and it would die at idle. Adjusted them and its perfect.

You can check your ignition system while the car is running too. Have the car idle and pull a plug wire. If the car shuts off, evertyhings okidokie. If not then you got a problem. How does the car idle? Maybe the IACV is dirty? I'm just throwing out ideas.

gearbox

iTrader: (95)

get rid of the bosch plugs for some NGK