idle high/surge after cleaning throttle body

[codym]

So today I cleaned my throttle body out, removing a good 1mm of carbon build up inside. After doing so I put everything back together and it is idling at 3000 rpm. It will fluctuate a bit, and when I tap the accelerator it will rev a bit and go down to 1, and back up to 3. I have double and triple checked all connections and hoses. Please keep in mind it is a 420a so from what I know there is no BISS screw and if there is I haven't been able to locate it.

 

[psx]

did you use a new gasket?
Because i remember changing out my TB and it had some weird idle problems.
And are you sure their isn't any vacuum lines missing?

 

[MotorHead265]

Sounds to me like you have a leak somewhere or a sensor unplugged. Did you replace the TB gasket when you cleaned it up?

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

this can be used to help diagnose a idle issue, some good stuff here that may apply.

 

[codym]

I took it apart this mornig and found that the gasket was in about 5 different pieces, so I went and got a new one. It's idling perfect now no surges or nothig. While I'm on, is there any easier way of cleaning the intake manifold other than lifting the engine out?

 

[92AWDHX40]

Maybe pulling it off? do your best to clean it with it on, lots of work.

 

[Chief-72]

Did you take the (IAC?) off of the throttle body before you cleaned it? If you didnt its possible that some of the gunk got down in there and is not letting it work like it should. You can take that off and clean it up as well, if the rest of the throttle body was dirty, its almost a sure bet that the idle control is dirty as well.

 

[Wil_OwnU]

Mineral spirits does wonders on cleaning automotive stuff up just a thought.

 

[codym]

I did take the IAC off. I just found my little wire brushes so I'm going to attempt to clean out the intake manifold tomorrow. The only problem is that it bolts together from the bottom not from the top. It should be easier since I trashed my windshield fluid resevoir(forgot how to spell that)

 

[ENICKB]

i recommend DeepCreep/Seafoam from advanced auto for cleaning out intake manifolds! it does your injectors and many other parts at the same time, put 10% in your oil, 30% in your gas, and rest should be sucked up using brake booster hose... see youtube videos of how to deep creep. itll change your car for the best. improves gas mileage etc

 

[codym]

I might have to check it out bro. To other posters- the gasket was the issue I replaced it and its wonderful

 

[Beastman]

I'm having the same issue with my RS, I had to change out my throttle body due to mine not able to pass California emissions because it's not stock and has no EOS number and now I'm getting the same idle issue as OP. I'm going to check out my gasket in a few and let you know the result.

 

[Fotowntalon]

I took it apart this mornig and found that the gasket was in about 5 different pieces, so I went and got a new one. It's idling perfect now no surges or nothig. While I'm on, is there any easier way of cleaning the intake manifold other than lifting the engine out?

Best way to take the IM off is through jacking the jack up and using 1-2 foot of 3/8th's ratchet extensions.

 

[jpmxrider489]

Spray starter fluid and and if the idle picks up, then you found the leak.

 

[Beastman]

I replaced the gasket, cleaned the throttle body but now it wont fire :/

 

[96eclipse_rst]

Same thing happened to me in my 99 GS. I took the whole thing off and cleaned the entire thing. Put it back on and my rpm's were back to normal