Rep Power: 0

i have a problem i dont know how to fix!!! i have a 2000 civic with a d16y7. the car runs great while its driving, but as soon as its at idle, it just stumbles bad. i have changed fuel injectors, plugs, wires, rotor, and dist. cap. i cant figure out what it is. if anyone knows what this problem might be, please let me know. it is definately killing me.

Thanks
Damian

 
Rep Power: 811

did you clean out the intake parts like throttle body, IAC (idle air control) valve, and fast idle valve? they are all bolted around the throttle body or intake mani and can be disassembled for cleaning. most likely thats what it is. too much carbon inside the parts so get a can of carb cleaner and spray them down.

 
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i havent done that yet but i will. thanks gearbox. i also have heard something about an iat sensor? im fairly new to honda so i need all the advice i can get. where is the iac valve located, and what does it look like. thanks again.

 
Rep Power: 811

iac valve is a small sensor piece bolted to the throttle body and usually has coolant lines going into it. iat is the intake air temp sensor which is unrelated to idle, usually located in the air intake somewhere.

 
Rep Power: 0

sounds like a vacuum leak in the intake manifold.

 
Rep Power: 0

ok cool, thanks. is there a way i can test to see if the sensor is bad? i put a obd scanner on it and it said that the maf and iac sensor had high output and it was misfiring 3 out of 4 cylinders. im so confused.

 
Rep Power: 811

well if cleaning the iac doesnt fix the problem , chances are you need a new one. and usually they are not sold separately, so you will have to find a whole throttle body assembly. theyre fairly cheap on ebay for used piece. maf sensor can be cleaned as far as i know, but get the special MAF spray cleaner because the carb cleaner will destroy it. misfire could be related, but usually is due to plugs or wires gone bad.

 
Rep Power: 0

i replaced the map sensor today and still stumbling. i was wondering if it was some internal part of the distributor that might be causing it? i have replaced the rotor and cap so far. thanks again

 
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i replaced the iac valve and it smoothed out and then all of a sudden it threw a check engine code saying low input. i bought it used. but on the green casing on the valve it had a large number that said 54. the one i replaced it with said 52. idk but im confused. can someone plz help asap. thanks

 
Rep Power: 811

make sure the iac valve is the correct one. theres two different ones for auto and manual trans.

 
Rep Power: 0

ooh ok!!. thanks again.

 
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ok so i replaced it today and its surging. idk but it seems like the computer is trying to catch up to it or something. but i desperately need help!!!!

 
Rep Power: 811

well try disconnecting the battery and then letting the car idle at normal temp til it relearns the idle. other than that, it sounds more like a vacuum leak now.

 
Rep Power: 0

yeah i tried that but it still does the same thing. ill look for a leak but i havent found one yet. thanks for the help

 
Rep Power: 213

Is that the Idle Learn process?


-Thanks

 
Rep Power: 811

idle learn process:

1. drive the car til its warmed up.
2. turn car off, either disconnect battery or pull FI ECU fuse, then reconnect.
3. start car, make sure all accessories are OFF and do not press the gas. close hood.
4. let car idle for 10 mins.
5. turn car off
6. turn car on and drive like you normally do. it will take upto a tank of gas to completely relearn the fuel trims. but the idle will be set already.

 
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ok. so i have done the idle learn process twice now. i have had it vaccum tested and it still sputters. i think im just gonna give up on it. i have tried just about everything except maybe the distributor might be causing it. or maybe a bad valve, but i just had the head redone. i dont know, but im totally lost. please help. thanks

 
Rep Power: 213

I wonder if i floor it the whole time for step 6^^^ if it'll think I'm a speed demon and add hp!

 
Rep Power: 811

i forgot you have an older civic. it might be the other valves on the throttle body, the fast idle thermo valve and one other. they are bolted around the tb and intake mani. be sure to clean them all. and check all the vacuum lines. it could also be the distributor rotor button is worn out or the cap too. if those dont work, try adjusting the ignition timing.

 
Rep Power: 0

i have replaced every sensor except the tps. it doesnt have fitv because its an obd2 .it has an iac valve bolted to the tb. the cap and rotor are new also. i have tried adjusting the timing also. lol. sorry for the trouble. im just trying to figure this out. thx

 
Rep Power: 213

Is there a DIY for this?

-Thanks

 
Rep Power: 213

I took the throttle body and the IAC Valve off today and clean them pretty good with simple green. The intake manifold had a lot of carbon build up, but i didn't know how to clean it out properly. Put everything back on and seems good so far. Now my question is how to clean out inside of intake manifold without taking it off? (if there is a way?)

-Thanks