continuous fight with p0505 CEL

[jc27]

I've had the p0505 code for about a year now. My hatch would have a fluctuating idle and would jerk when I was in gear and would let of the gas. The car would no jerk in neutral, just when I was in gear and wasn't putting my foot down.

After trying to find multiple cheap ways to fix it, such as buying an eBay IACV I decided to go buy a OEM IACV. Before buying it I made sure that I had no vacuum leaks and that the throttle body and previous IACV was clean.

Since I put my OEM IACV the jerking has stopped, Finally!!! I would sometimes have to ride my clutch and always shift to neutral on a daily basis. BUT I still have the p0505 code and have a low idle. So since the jerking stopped I am certain that the new IACV is working properly. When my car is warmed up the idle drops, but it doesn't fluctuate. I don't have a tachometer so im guessing it drops to 800-700, enough to make the engine shake and cause vibration throughout the car. I notice one of the reasons for the p0505 code could be electrical. Also once the idle drops if I give I gas I will go back up. So my guess is that the connector that connects to the IACV must be faulty.

Has anyone else experienced this? how do I go about fixing this? The vibration is very annoying and it causes my hood to vibrate loudly and I worry about the engine idling so low.

 

[Esotericimage]

Have you tried to adjust your idle manually?

Clean your throttle body?

 

[jc27]

Yes I have cleaned my throttle body and I'm worried about adjusting the iacv. I don't want to mess it up especially since it cost me a pretty penny

 

[ekcoupeproject]

Check for an intake leaks,grab a can of brake cleaner and start the motor and while on spray all around intake manifold

 

[jc27]

Check for an intake leaks,grab a can of brake cleaner and start the motor and while on spray all around intake manifold

I'll try that out. My problem is that the car is throwing me the CEL so its screaming for my attention and has narrowed it down. I don't think fixing an intake leak would turn the light off because it doesn't show as something that would trigger the code P0505

 

[ekcoupeproject]

P0505 idle air control malfunction meaning it's not regulate the air come in engine there's an extra air coming in somehow ,you change the lac two time's , unless there's a problem with the wiring or the ECU most likely not but it does happened going thru the same still working on my

 

[ekcoupeproject]

There's a harness connection under the intake manifold that connects the main engine harness to the ecm they tend to bend or crack you can check there but I doubt it because the fact that is thrown a p0505 code meaning its communicating with the computer

 

[jc27]

There's a harness connection under the intake manifold that connects the main engine harness to the ecm they tend to bend or crack you can check there but I doubt it because the fact that is thrown a p0505 code meaning its communicating with the computer

I checked for leaks. I sprayed brake cleaner all over my intake manifold while the car was on, it just evaporated right away. I didn't see any bubbles or notice any change. This code is driving me crazy

 

[jc27]

There's a harness connection under the intake manifold that connects the main engine harness to the ecm they tend to bend or crack you can check there but I doubt it because the fact that is thrown a p0505 code meaning its communicating with the computer

could it possibly be the tps or map? I changed them awhile back before I bought a new iacv but it didn't do anything so I just returned them.