I've got a really annoying problem going on with my car. Recently I've installed a big upgrade, Brian Crower BC002 cams, Haltech platinum pro etc.
After everything was installed and the Haltech tuned, the car was running great, but I've seem to gain a new headeach also!

My TB is an OBX 72mm. The build quality isn't great, and I've always noticed some butterfly "play". Sometimes it seemed to be a little stuck at idle, but a little more pressure on the accelerator pedal would resolve it. But now the car's idle is completly nuts! It never goes down 1300rpm , and the "normal" is being at 1500+ rpm.
Sometimes I'm driving normaly and the car stucks the rev's on 5000rpm without me touching the accelerator!

To stop this I have to accelerate a bit hard, and then It goes back to 1500rpm +/-

Why is this happening? Could it be from the TB's butterfly not being precise? Or is this a problem with the Idle control vavle?

I really need some help with this one, I can't drive my S like this :-(

I'm thinking of taking the Throttle Body off, and getting a new butterfly for it done.

 

Sounds like a mechanical issue with the TB, cable too tight, or TPS "rest" value not tuned.

 

Remove the inlet pipe to the throttle body. Use your finger to partially block the port in front of the throttle plate that goes to the idle motor/valve. If you can put your finger completely on it then the high idle is due to air leaking past the throttle plate.

If you can bring the idle down by blocking the port then its an idle motor, or more likely the Haltech configuration. the idle part of the program has stuff like min/max duty, initial position, throttle/rpm where it goes into idle mode etc etc. Its not difficult to get some parameters wrong causing the idle to hang on a high rpm.

 

But if it's the Haltech configuration, shouldn't it always say at high idle?

I'll do those checks. I'm thinking of TPS values maybe or dirty Idle control valve...so I hope!

Thanks for the awnsers

 

It depends on the haltech idle configuration.

For example, if your initial idle duty cycle is set too high the revs can get stuck above the idle control below rpm figure. If something like the radiator fan kicks in or headlamps are on, or you are slow to push in the clutch the rpm may get below the idle control below rpm figure and closed loop idle will kick in. There are several things that need to fall into place for idle control to kick in.

 

Thanks for the help Chris!

 

If you only had the big bore throttle body upgrade as the only change I would say the TPS settings are out of whack on the TB. But I can't speak to the changes introduced by the Haltech.

I had the same high idle issue when I installed my J's Racing TB, the TPS open % was set too high. It was an easy fix by loosening the TPS bolts and turning the TPS downwards to lower the opening %. As soon as I turned the TPS downwards the idle lowered to a more reasonable level.

The sticking throttle plate is common with low quality modified throttle bodies. The throttle plate is closing too far back and too tight into the throttle body bore. The TB should have a lower adjustment bolt to stop the plate from closing too tight into the bore. You would normally raise up the bolt a very tiny amount to stop the throttle plate at the correct spot, don't go crazy though because if you raise it too high the throttle plate won't seal up tight enough and you will get too much air flow around the plate causing high idle conditions. You need to play with it a bit to get a happy medium between a good sealing plate that isn't too tight in the bore.

I can't believe how many manufacturers send out modded throttle bodies with incorrectly set TPS and throttle plates. This should be a quality control check before the part is released rather than expecting the customer to make the adjustments. Bad service IMO.

 

I finally found out what was my problem. The screws that hold the butterfly on the obx throttle body are smaller than the ones on the stock Honda throttle body's, and they seem to be prone to unscrew themselfs.

After re-screwing them and aplying some screw specific glew, everything worked fine!!!

Problem solved!