code p0505???

[TheNewGuy98]

ok my chech engine light came on.. so i took my car down to the shop to get it checked out and it ran the code p0505(idle air control) i looked around at some other forums and it seems like almost everyone else with this problem is also having problems with bad idle or stalling.. but my cars not runing any different. the idle hasent changed at all sence the light came on... whats the problem???? do i just need to clean out my TB or something???

 

[Rice Over Wheat]

Very common problem. I have it too but it's not absolutely crucial so I just ignore it. You can replace the idle air control unit with a new one for about $200. Some people disable it altogether.

 

[luv2rallye]

Does the idle drop when you turn on a bunch of accessories or is it too high/low when engine is warm/cold? If you wish the test proceedure send me a PM.

 

[TheNewGuy98]

no thats the thing that i dont understand the cars not runing any different. it idle dosent drop below about 850-900. ive turnd on every electronic in the car(A/C, lights, radio, ext...) and still no difference. the only time the idle is above 1100 rpm is on warm up on a cold morning. other than that theres nothing wrong. i read another forum, and the guy said that he solved the problem by taking the T/B off and cleaning everything real good. would that work.. or just a wast of time??

 

[silvah_gsx]

Well cleaning it is never a waste of time, but 850-900 is a tad high for a warm engine. Mitsubishi set it to be around 750, give or take 50 rpm.

 

[TheNewGuy98]

i know its alitle high, i adjusted it a few monthes ago.. IDK why but it makes it easyer to put in 1st at a stop... but could that be the problem??

 

[DSMunknown]

no thats the thing that i dont understand the cars not runing any different. it idle dosent drop below about 850-900. ive turnd on every electronic in the car(A/C, lights, radio, ext...) and still no difference. the only time the idle is above 1100 rpm is on warm up on a cold morning. other than that theres nothing wrong. i read another forum, and the guy said that he solved the problem by taking the T/B off and cleaning everything real good. would that work.. or just a wast of time??

It's odd to me that your CEL came on. I am experiencing the same thing, but as it has been said before, I just ignore it. I cleaned out my TB, TB elbow, and a few other things (check my mod list) back in September. It helped smooth out my idle because there was so much grime just sitting there. So again, it's not a bad thing to be proactive and do some maintenance every once in a while. But adjusting your BISS screw should help out quite a bit. And make sure you don't have any air leaks.


Boost leak test #1
Boost leak test #2
Idle surging and ISC unit
TPS adjustment

Very common problem. I have it too but it's not absolutely crucial so I just ignore it. You can replace the idle air control unit with a new one for about $200. Some people disable it altogether.

Yup.

 

[luv2rallye]

P0505 will be generated when the "actual idle speed has continued to be higher than the target idle speed by 300 r/min or more for 10 sec" (this from 99 Mitsu service manual). So if you force the idle speed higher (by Biss or whatever) you may get P0505's when this condition is met. So you could ignore it (since you forced it) but the problem then becomes how do you know your CEL isn't on for something else?