Ok, I have sarted to prepare a spare throttle body, EBB style, intended to improve performance on my 1.0
As you can see the butterfly valve 'stem' has been reduced in its proportions to reduce the blockage it represents when fully open. The smallest diameter at the bottom of the TB is 46mm. I don't know how big the 1.5 or 1.6 Tb's are, perhaps this is a 'halfway house' flow capacity improvement? I couldn't undo the screws holding the brass disc so I just atacked it with my dremmel and left a bit of the head behind.
I have removed the waxstat - the wax is in that bottle shaped piece with the plunger in the top, it is heated by the flow of coolant passing by in the two rubber pipes visible right and left. The bit with the big green spring wound around it connects it to the butterfly valve. It's job is to be to prevent the throttle from closing fully until the engine is warmed up. Removing the piece with the green spring disconnects it. The coolant pipes can be connected together so the tb heats up less in use giving the engine marginally colder denser air to breath. The tb temp will still rise in use due to conduction from the cylinder head via the intake manifold but hey, every little helps.
Next came the intake air valve IAV
It hs a rubber O ring that sits on the top of it which was stuck in the casting. I removed the pair of lock screws but it wouldn't come apart any further. The inside of this rotates to open and close a pair of small windows (one visible, one opposite),you can work it with the tip of a finger and I read it should be free and easy to do so, fortunately mine is. Clearly it's connected to a motor which is controlled by a signal from the ecu to open and close it. I understand this is also to keep the engine running while it warms up and it can operate in conflict with the waxstat, particularly if the waxstat sticks in it's cold start position. I read that it can do the cold starting job perfectly well without additional assistance of the waxstat, giving further confidence to waxtstat deletion.
Next the TPS Throttle position senor
Clearly a simple potentiometer which sends a signal to the ecu to tell it how much the throttle is open. It does however have slotted mounting holes, and can be rotated when installed. I don't know where to positon it and I'd like to know how to put it back properly. That's what prompted this post in the first place! lol
This TB is off a '98 1.3 which had covered 54k miles. It worked nicely when I parked it hence I don't feel the need to open it up and resolder the maf connectons. I attempted to clean a maf on a vag tdi recently and somehow, by wiping i with soaked cotton buds, I managed to damage it. That was describd as a 'hot film' type. Is there any likelihood that could happen in this case?
Anyhow I enjoyed my afternoon dismantling and trying to understand a throttle body. Is there anything else I can do to enhance it's performance and reliability?
As you can see the butterfly valve 'stem' has been reduced in its proportions to reduce the blockage it represents when fully open. The smallest diameter at the bottom of the TB is 46mm. I don't know how big the 1.5 or 1.6 Tb's are, perhaps this is a 'halfway house' flow capacity improvement? I couldn't undo the screws holding the brass disc so I just atacked it with my dremmel and left a bit of the head behind.
I have removed the waxstat - the wax is in that bottle shaped piece with the plunger in the top, it is heated by the flow of coolant passing by in the two rubber pipes visible right and left. The bit with the big green spring wound around it connects it to the butterfly valve. It's job is to be to prevent the throttle from closing fully until the engine is warmed up. Removing the piece with the green spring disconnects it. The coolant pipes can be connected together so the tb heats up less in use giving the engine marginally colder denser air to breath. The tb temp will still rise in use due to conduction from the cylinder head via the intake manifold but hey, every little helps.
Next came the intake air valve IAV
It hs a rubber O ring that sits on the top of it which was stuck in the casting. I removed the pair of lock screws but it wouldn't come apart any further. The inside of this rotates to open and close a pair of small windows (one visible, one opposite),you can work it with the tip of a finger and I read it should be free and easy to do so, fortunately mine is. Clearly it's connected to a motor which is controlled by a signal from the ecu to open and close it. I understand this is also to keep the engine running while it warms up and it can operate in conflict with the waxstat, particularly if the waxstat sticks in it's cold start position. I read that it can do the cold starting job perfectly well without additional assistance of the waxstat, giving further confidence to waxtstat deletion.
Next the TPS Throttle position senor
Clearly a simple potentiometer which sends a signal to the ecu to tell it how much the throttle is open. It does however have slotted mounting holes, and can be rotated when installed. I don't know where to positon it and I'd like to know how to put it back properly. That's what prompted this post in the first place! lol
This TB is off a '98 1.3 which had covered 54k miles. It worked nicely when I parked it hence I don't feel the need to open it up and resolder the maf connectons. I attempted to clean a maf on a vag tdi recently and somehow, by wiping i with soaked cotton buds, I managed to damage it. That was describd as a 'hot film' type. Is there any likelihood that could happen in this case?
Anyhow I enjoyed my afternoon dismantling and trying to understand a throttle body. Is there anything else I can do to enhance it's performance and reliability?
