Hey guys it seems as though everytime i try to do something good to or for my car something goes wrong. The other day i cleaned my throttle body and it ran better than ever for 30mins, not i get a p0505 which is idle control system, i have a high idle and when the car is fully warm and i let it idle, it goes into like this backup mode and idles at1500 rpms and if i give it just a little gas it surges almost sounds like a 2 step. and is very jerky to drive. also before it goes into this mode when i free rev it it will rev nice and drop down to 1000 or so and then climb right back up to 1500 and then slowly drop. I have a scanner and all the sensors are ok and reading fine. Whats weird is that when i force the throttle plate down to close more snuggly the idle drops a bit? Any suggestions i was thinking to take the throttle body off and clean it a little better but could it be that the throttle plate is not sealing now that ive removed all the carbon and stuff around it? it would explain the idle drop. Any suggestions are awsome. Cheers!!
High idle and P0505 after cleaning TB
- Thread starter ri.S.I.R.
- Start date
sounds like an vacuum leak. the why id always check for leaks is by having the car run and then spray brake cleaner in certain areas. and if there is a leak rev goes up or bogs and presto! found the vacuum leak. 
again. thats how Ive done it LOL
again. thats how Ive done it LOL
I found out that there is an adjustment for the throttle plate. I think i had to do it like 12 times but it finally feels right and it seems to have fixed it. Well see on the drive to work but yeah. Its pretty amazing casue its such a precise fit if you loosen it too much where the plate comes in tighter to the walls it actually sticks. thanks for all your help.
I'm basically having the same problem your having. I have a car scanner and everytime the check engine light comes on I delete the code and idling returns to normal. Do you delete the code and does it run fine for you?When I've deleted the code I'll be at a red light and the check engine light will come on and the car will idle at 1500rpm and when I gas the rpms will bounce from 1500 to about 1600 and I really gotta give it more gas to get moving.
Yeah at a red light it will come on and it will surge everytime i give it gas. When i delete the code the idles drops down. I adjusted that throttle stop and it actually fixed my problem, I havent had the code come on for about 2 days and it idles normally at 800rpm. did you clean ur TB recently Mad-Mike? casue mine happened right after i cleaned mine. My theory is that after i cleaned it, the throttle plate wasnt sealing anymore becasue it didnt have that carbon and soot around it. Just my theory dont start flaming me about it. RonJ howcome your not supposed to adjust it?
RonJ
Banned
It's set at the factory to ensure the perfect position of the throttle plate at closed throttle. When the idle is off, you should adjust the idle screw on the TB not the throttle stop screw. People who mess with the stop screw often can never get the idle set properly again. You got lucky, at least for now.
I just sprayed Carb cleaner all over the TB but the high idle problem still existed. I believe I have a vacuum leak in one of the lines but don't know which one...I wanna fix it cause I can't go a whole day without having the light going on and having my car shaking like a b***h when driving. I feel that I'm gonna f**k up my engine mounts cause the car jerks really bad.
RonJ
Banned
Pull off the intake when the engine is idling too high and P0505 is thrown. Then use your finger to cover the lower port hole inside the throttle body leading to the IACV. Does the idle speed drop when you do this?