P0505 Code, got new IACV, code returned

[JohnS.]

So I had a P0505 code and I read the most common solution was replacing the IACV. Well I bought a used one off someone on here and supposedly it was in good working condition. So I got home yesterday, put it in, reset the ECU, and prayed the code wouldn't come back. Well today it did. I haven't scanned the CEL but I know it's P0505. It hasn't been anything else for the past month or two the CEL has been on lol.

I'm positive I don't have any vacuum leaks. Other than cleaning the IACV 3-4 months ago, I haven't touched the engine bay in over a year. I did remove cruise control like 3 or 4 years ago but I covered up the nipple behind the I/M. My intake is sealed up nice and good along with all the holes in it.

What else could I do?

EDIT:
I fixed the code! It turns out I had my idle screw way too far out when I was adjusting my idle after cleaning the IACV. I read my Haynes manual to properly adjust my idle and I ended up turning the idle screw in atleast 2 full turns! Yay for no more bouncing idle and bogging!

 

[RonJ]

1) Verify P0505 before you do anything.

2) Tell us what kind of idle problem you have - high, low, hunting, none?

 

[JohnS.]

2) Tell us what kind of idle problem you have - high, low, hunting, none?

Same as before I replaced the IACV. Idle will hover between 1500 and 1700 and when I give it just a little gas, it revs up and down really fast between 1500 and 1700. If I give it a little more gas, it'll rev up normally. When I drive in gear, when I left off the gas, the engine jerks really hard. Same goes when I press the gas. And if I'm in a gear with the RPM's between 1500 and 1800, it'll bog REALLY hard. Weird part is, if I turn the car off while the problem occurs, then turn it right back on, it goes away and the RPM's drop down to normal. Then it comes back randomly, sometimes for days, sometimes for longer, sometimes quicker... It's random. But I can get rid of it if I shut the car off and turn it right back on. CEL stays on though.

I'll get it scanned tomorrow maybe. I don't have a scanner so I have to shoot down to Advanced Auto to get it scanned and cleared.

 

[d16racer88]

is this manual or auto and what iacv did you buy?

 

[JohnS.]

Manual and I bought an IACV from the exact same car as me.

 

[RonJ]

Idle will hover between 1500 and 1700 and when I give it just a little gas, it revs up and down really fast between 1500 and 1700. If I give it a little more gas, it'll rev up normally.

Does this happen when the engine is cold, hot, or either?

When I drive in gear, when I left off the gas, the engine jerks really hard. Same goes when I press the gas.

Do you mean the engine abruptly decelerates and accelerates? This is normal if you are in a low gear, right?

And if I'm in a gear with the RPM's between 1500 and 1800, it'll bog REALLY hard.

You mean the engine loses power and misfires in that specific rpm range?

I'll get it scanned tomorrow maybe. I don't have a scanner so I have to shoot down to Advanced Auto to get it scanned and cleared.

Speed this up John by jumping the service connector to see whether code 14 or some other code is thrown.

 

[mal2000si]

omgosh im literally haveing the same problem in my si, when your in low rpms (like under 2000) it feels almost as if your about to stall out, i found out that if you keep you air compressor on that it doesnt do it.

but seriously im having the same problem and i really wanna know what it is before i spend $200 on an iacv

 

[RonJ]

i really wanna know what it is

Don't hold your breath. John has had this P0505 problem for about ten years now. He replaces one part that does not fix the problem about once every three years. If my memory serves me correctly, he replaced the air filter three years ago. We hadn't heard from him until now.

 

[JohnS.]

Don't hold your breath. John has had this P0505 problem for about ten years now. He replaces one part that does not fix the problem about once every three years. If my memory serves me correctly, he replaced the air filter three ago. We hadn't heard from him until now.

Does this happen when the engine is cold, hot, or either?

It seems to only happen when the engine is warm/hot. Hasn't happened when it's cold yet.

Do you mean the engine abruptly decelerates and accelerates? This is normal if you are in a low gear, right?

No. I mean that when I'm in gear, it doesn't matter what RPM or what gear, and I let off, the entire car will jerk and shake really hard. Same goes when I press the gas. It's like abruptly letting off the gas in 1st gear at 20mph, just more violent.

You mean the engine loses power and misfires in that specific rpm range?

No. If I'm in any gear between 1500 and 1800 RPM and I try to press the gas to go, the entire car starts shaking and jerking constantly very violently. Just like when I lightly press the gas in neutral and it revs up and down really fast between 1500 and 1700. It does the same thing (even the rev'ing up and down really fast) when I'm in gear except throw on the violent shaking unless I downshift and raise the RPM past 2000.

Speed this up John by jumping the service connector to see whether code 14 or some other code is thrown.

It's too cold out to do that . Getting damn near 30 degrees at night now. I woke up with frost all over my car. I actually used the scraper on the snow brush for the first time this year.

 

[mal2000si]

haha, okay. i unplugged my iacv while the car was running and the idle messed up, so my iacv isnt bad becuase its controlling it, i must just have a vacuum leak.

 

[RonJ]

haha, okay. i unplugged my iacv while the car was running and the idle messed up, so my iacv isnt bad becuase its controlling it, i must just have a vacuum leak.

A vacuum leak causes a high or fluctuating idle not a low idle.

 

[RonJ]

It seems to only happen when the engine is warm/hot. Hasn't happened when it's cold yet.

No. I mean that when I'm in gear, it doesn't matter what RPM or what gear, and I let off, the entire car will jerk and shake really hard. Same goes when I press the gas. It's like abruptly letting off the gas in 1st gear at 20mph, just more violent.

No. If I'm in any gear between 1500 and 1800 RPM and I try to press the gas to go, the entire car starts shaking and jerking constantly very violently. Just like when I lightly press the gas in neutral and it revs up and down really fast between 1500 and 1700. It does the same thing (even the rev'ing up and down really fast) when I'm in gear except throw on the violent shaking unless I downshift and raise the RPM past 2000.

It's too cold out to do that . Getting damn near 30 degrees at night now. I woke up with frost all over my car. I actually used the scraper on the snow brush for the first time this year.

John, you may have more than one problem.

How old are the spark plugs, wires, cap, and rotor? Are you using properly-gapped basic NGK plugs?

When the engine is warm and having the fluctuating idle problem, remove the air intake and cover the port inside the throttle body leading to the IACV with you finger. Does this make the idle settle down?

Stop whining! Put on a jacket and pull the codes.

Please tell me that you own a multimeter.

 

[RonJ]

See you in three years John.

 

[Hecz]

so code P0505 is aka code 14?

Diagnose the valve? or circuitry

When the engine is warm and having the fluctuating idle problem, remove the air intake and cover the port inside the throttle body leading to the IACV with you finger. Does this make the idle settle down?

That would be the top port.

That's supposed to stall the motor, right?

 

[mal2000si]

Okay, I checked the almighty haynes manual and it said that the iacv and pretty much all other sensors are sent to the pcm, which reads al the information (like engine temp ect) and sets the idle, I do not have an 02 sensor or temp sensor, so ima replace those and see if it fixes it,

Did I comprehend the information correctly? Or am I completely wrong? Haha

 

[mal2000si]

Okay, I checked the almighty haynes manual and it said that the iacv and pretty much all other sensors are sent to the pcm, which reads al the information (like engine temp ect) and sets the idle, I do not have an 02 sensor or temp sensor, so ima replace those and see if it fixes it,

Did I comprehend the information correctly? Or am I completely wrong? Haha

 

[Hecz]

damn I think I got his code going also. Mil turned on on my way to class. Jumped it, I'm only reading on lonn flash. Increment of ten. I cleaned the valve on weekend, I have a feeling that has something to do with it. *sigh*


:edit:

in between class,

I jus re-jumped the connector. not code 14 but its code 10. Intake Air Temperature.

Sorry John, didn't mean to threadjack, just was ready to tackle this code with you.

 

[RonJ]

damn I think I got his code going also. Mil turned on on my way to class. Jumped it, I'm only reading on lonn flash. Increment of ten. I cleaned the valve on weekend, I have a feeling that has something to do with it. *sigh*


:edit:

in between class,

I jus re-jumped the connector. not code 14 but its code 10. Intake Air Temperature.

Sorry John, didn't mean to threadjack, just was ready to tackle this code with you.

Reset the ECU to see whether code 10 returns.

 

[Hecz]

Reset the ECU to see whether code 10 returns.

Alrighty, its resetting right now. i'll let you know how it goes.

 

[JohnS.]

John, you may have more than one problem.

How old are the spark plugs, wires, cap, and rotor? Are you using properly-gapped basic NGK plugs?

When the engine is warm and having the fluctuating idle problem, remove the air intake and cover the port inside the throttle body leading to the IACV with you finger. Does this make the idle settle down?

Stop whining! Put on a jacket and pull the codes.

Please tell me that you own a multimeter.

Spark plugs I just got within the last 2k. They're OEM Honda. Wires, cap, and rotor probably have around 40-60k on them.

I actually bought a new battery yesterday because my old one was starting to have problems getting the motor started in this cold weather. So the CEL is gone. Next time it comes up, I'll get it scanned and see if I'm willing to man up and do the intake thing.

I do not own a multimeter. I have no use for one. Literally. I would use it probably half a dozen times a year, if that. I bought a battery operated 12V drill around summer time last year. Guess how many times I've used that since... Less a dozen. I just don't have uses for a lot of tools except the usual hand tools to do car maintenance.

And I'm usually in bed by 10-10:30 every night since I work 7-3:30. So that's why I do not post late anymore.