Hello all,

I have been doing a lot of reading of old posts. I have an issue of 'rev hang' where the revs do not drop once I release the accelerator pedal. I also have strange revs at idle where it can sit at 1k or 1.5k or even 2k sometimes, until I turn the engine off and on again and it seems to reset back to its normal at around 0.8k. At first I thought it was perhaps a vacuum leek but I have smoke tested and found none. Today I used a multimeter on the TPS pins to read the resistance between pin 1 and pin 2 whilst moving the throttle body and found near 0 ohms in every position. This suggests to me that the sensor now is telling the ECU that the throttle is idling all of the time.

Is my interpretation correct? Is it time for a new throttle body? In which case, does anyone have any recommendations for a replacement for 030 133 064 D?

Thank you

10 hours ago, TrentBarton said:

I also have strange revs at idle where it can sit at 1k or 1.5k or even 2k sometimes, until I turn the engine off and on again and it seems to reset back to its normal at around 0.8k. At first I thought it was perhaps a vacuum leek but I have smoke tested and found none. Today I used a multimeter on the TPS pins to read the resistance between pin 1 and pin 2 whilst moving the throttle body and found near 0 ohms in every position. This suggests to me that the sensor now is telling the ECU that the throttle is idling all of the time.

1.6?

Hey @Thefeliciahacker , that's right. 1.6l 2000.

its old school engine from 1980-is, modernized and fuel injected with cat.

constructional not different from old model with carburetter.

that engine was also in vw golf 1 GTI with MPI injection pump, 110 hp. my friend had all those GTI-s till todays new mode. later replaced with 1.8.

Edited 27 January27 Jan by imart143

Yes that is all true. But I was wondering if anyone has had experience doing the pin test on the throttle position sensor, if my diagnosis is correct, and experience replacing the body.

According to schematics, pins 1 and 2 are for actuator. Potentiometer pins are 4, 5 and 7 for absolute position and 4, 8 and 7 for idle position (two potentiometers, 7 is common ground, 4 is common voltage input from ECU and 5 and 8 are outputs of each potentiometer).

On 27/01/2026 at 08:55, imart143 said:

its old school engine from 1980-is, modernized and fuel injected with cat.

constructional not different from old model with carburetter.

that engine was also in vw golf 1 GTI with MPI injection pump, 110 hp. my friend had all those GTI-s till todays new mode. later replaced with 1.8.

The engine on the photo is EA827. Felicia has an entirely different engine, EA111, which was derived from 0.9-1.3 engines used in Polos.

Edited 29 January29 Jan by Papez

On 26/01/2026 at 19:49, TrentBarton said:

I have an issue of 'rev hang' where the revs do not drop once I release the accelerator pedal. I also have strange revs at idle where it can sit at 1k or 1.5k or even 2k sometimes, until I turn the engine off and on again and it seems to reset back to its normal at around 0.8k. At first I thought it was perhaps a vacuum leek but I have smoke tested and found none. Today I used a multimeter on the TPS pins to read the resistance between pin 1 and pin 2 whilst moving the throttle body and found near 0 ohms in every position. This suggests to me that the sensor now is telling the ECU that the throttle is idling all of the time.

Is my interpretation correct? Is it time for a new throttle body? In which case, does anyone have any recommendations for a replacement for 030 133 064 D?

Thank you

Hi,

I have a similar issue where the engine starts at around 1.5k revs and stays there. Once the engine gets warm it can (but not always) start to hunt. I was wandering if you found anymore instructions on how to do a pin test for the throttle body and where you’ve got to with your own issue?

Regards Rob

5 hours ago, Rsedmonds said:

Hi,

I have a similar issue where the engine starts at around 1.5k revs and stays there. Once the engine gets warm it can (but not always) start to hunt. I was wandering if you found anymore instructions on how to do a pin test for the throttle body and where you’ve got to with your own issue?

Regards Rob

Right,

Expanding on my previous post and hoping @TrentBarton doesn't mind me highjacking his thread, I’ve done a few measurements and was wandering what other thoughts are of my findings. I’ve put a multimeter across the pins that were mentioned by @Papez and these are the readings I got when opening and closing the throttle body..

Actuator pin 1, open 6.52v closed 7.27v

Actuator pin 2, open 5.21v closed 4.54v

Voltage pin 4, ignition on 5.14v & off 0.0v

Ground pin 7, ignition on 0.12v & off 0.0v

Absolute pin 5, open 0.92v closed 3.98v

Idle position pin 8, open 2.48v closed 2.48v

Is the idle potentiometer bad?

Regards Rob

Can't say, I've never inspected the throttle body, but my guess is that the idle potentiometer is feedback of the actuator, so it doesn't move with the throttle valve, but only when the ECU tries to regulate the idle RPM

5 hours ago, Papez said:

Can't say, I've never inspected the throttle body, but my guess is that the idle potentiometer is feedback of the actuator, so it doesn't move with the throttle valve, but only when the ECU tries to regulate the idle RPM

What I've seen but not confirmed and was hoping someone on here could.

Is that the absolute and idle should read opposite to each other so that when the throttle is open the absolute reads 0.92v the idle should be around 4v. And when the throttle is closed the absolute reads around 4v and the idle somewhere in the region of 0.9v.

Hey @Rsedmonds . Not at all, all the help we can get here is helpful. Sounds like you have a very similar problem to me. Mine started in the way you describe and has recently developed into this intermittent 'rev hang' thing. Pondering whether to get a replacement throttle body and just give it a go if there isn't a clear diagnostic pathway.

12 minutes ago, TrentBarton said:

Hey @Rsedmonds . Not at all, all the help we can get here is helpful. Sounds like you have a very similar problem to me. Mine started in the way you describe and has recently developed into this intermittent 'rev hang' thing. Pondering whether to get a replacement throttle body and just give it a go if there isn't a clear diagnostic pathway.

I agree, hopefully someone more knowledgeable will come along soon and give us both the answers we need.

I did most my research on YouTube and there’s a lot on there but most people are only talking about an 3 pin connector and nothing like the 7 pins we have. I then came across a guy called ECU TESTING and he cover a bad throttle position sensor and explains the idle and absolute potentiometer position. Now it’s early days as I haven’t found anything else yet but going by what he’s saying I should have a fluctuating reading and not static on the idle.

Ah nice one. Can you put a link to that youtube video so I can catch up?

7 minutes ago, TrentBarton said:

Ah nice one. Can you put a link to that youtube video so I can catch up?

That took some doing.

16 hours ago, Rsedmonds said:

What I've seen but not confirmed and was hoping someone on here could.

Is that the absolute and idle should read opposite to each other so that when the throttle is open the absolute reads 0.92v the idle should be around 4v. And when the throttle is closed the absolute reads around 4v and the idle somewhere in the region of 0.9v.

That's redundant TPS for electronic throttle control. In schematics, it's just marked as TPS-1 and TPS-2, not idle throttle position and throttle position.

Felicia uses this weird in-between, where idle position is controlled by the ECU in limited range, but the rest is controlled by cable, independently from the ECU - so it would make sense that position sensors would be independent, too.

Also, potentiometers don't fail like this, unless there's a mechanical failure that would keep the wiper stuck in position. They usually fail open or show irregular values over the range.

How did you get measurements while powered? Would you be able to get measurements with the engine started?

2 hours ago, Papez said:

That's redundant TPS for electronic throttle control. In schematics, it's just marked as TPS-1 and TPS-2, not idle throttle position and throttle position.

How did you get measurements while powered? Would you be able to get measurements with the engine started?

when you say redundant are you saying the video doesn’t relate to the Skodas TPS?

I got the readings with the ignition on but the engine not running.

I’m happy to get the closed readings with the engine on but for obvious reasons I can’t get the open ones. I’ll get them later and post.

34 minutes ago, Rsedmonds said:

when you say redundant are you saying the video doesn’t relate to the Skodas TPS?

Yes, the video covers newer cars with fully electrically driven throttle valve. They use two potentiometers in tandem in both the throttle pedal and valve body to detect fault if one of the potentiometers fail, because stuck throttle valve could be dangerous.

These older cars are different, the throttle is moved directly by the pedal and the idle adjustment is basically just adjustable stopper with limited range. This is opened throttle body, where you can see range of the brown part that's controlled by the ECU:

Also, forgot to add that there's an idle switch on pin 3 - that lets the ECU know, that driver has let go of the throttle pedal.

Unfortunately I still cannot say how do the potentiometers work. I may be wrong about them being independent, but my guess is that the idle sensor only detects movement of the brown part.

Btw, you should be able to see some fault codes or weird values in diagnostics, if one of the sensors is bad.

Edit: found a video (though it's a 1.3), where you can see the independent movement of the valve and the adjuster. It also shows irregular movement caused by vacuum leak.

Edited 6 February6 Feb by Papez

That’s not a bad video to be fair. I like the idea of removing the vacuum pipe then capping it off to see what happens.

I attached my laptop with Delphi on and it couldn’t talk to the ECU. The previous owner had something either deleted or added to the ECU due to an ignition key/barrel issue but I don’t know anymore. I do have a computer in the garage that has vagcom on but that hasn’t been used in around 8yrs.

1 hour ago, Rsedmonds said:

The previous owner had something either deleted or added to the ECU due to an ignition key/barrel issue but I don’t know anymore

Could it be the immobilizer? Diagnostic data line goes through the immo unit, if it's faulty (or removed and deactivated in the ECU), diagnostics won't communicate with the ECU.

9 hours ago, Papez said:

Could it be the immobilizer? Diagnostic data line goes through the immo unit, if it's faulty (or removed and deactivated in the ECU), diagnostics won't communicate with the ECU.

I remember him saying something about the coil/ring around the ignition failing and its purpose being deactivated in the ECU. He gave it a name saying something like “I’ve had ***** added to the ECU. As you say most likely to do with the immobiliser as I have 3 keys one for each door and one for the ignition, all different. But as they say if it ain’t broke don’t try to fix it.

Edited 7 February7 Feb by Rsedmonds

5 hours ago, Rsedmonds said:

remember him saying something about the coil/ring around the ignition failing and its purpose being deactivated in the ECU.

If the immo unit was removed, the diagnostics cable ends in the connector. Has the diag ever been working?

Hi guys,

Just an update, I did some more testing over the weekend with the engine running and got some other/different readings.

At first the throttle body was doing the same thing of running fast and fluctuating.

But while doing the testing I had a big discovery, the engine lifting eye that has 2 earths connected to fell off. Once refitted the fluctuation seemed to settle down and only really happened after that when the cooling fan kicked in. I also noticed that there was tension in the throttle cable that didn’t seem quite right, it was tighter than I would like and had no slack in it. So with the slack removed the revs dropped to 800rpm and everything seemed to run smoothly.

Early days yet but fingers crossed 🤞

On 07/02/2026 at 14:08, Papez said:

If the immo unit was removed, the diagnostics cable ends in the connector. Has the diag ever been working?

Looking under the dash at the ignition switch there’s a 3 (I think) pin brown plug that’s not connected to anything which I assume is part of the immobiler.

16 hours ago, Rsedmonds said:

Looking under the dash at the ignition switch there’s a 3 (I think) pin brown plug that’s not connected to anything which I assume is part of the immobiler.

That's the plug that connects the pickup coil to the immobilizer unit. The unit was then connected by a 6-pin plug to ECU. One of the pins in the 6-pin plug is data wire from the diagnostic socket, so if it's unplugged (which is possible, since you found the 3-pin plug), there's no way for ECU to communicate with the diagnostic tool.

Hello all,

Thank you @Papez for all the information. I have the same issue as @Rsedmonds with no diagnostics, see here. Perhaps also related to immobilizer, interesting to read about this.
Glad you got your sorted @Rsedmonds .
I'm still struggling with mine, seems tricky to get a clear method of diagnosing using the multimeter.

Tempted to just put a new throttle body on and hope for the best unless anyone has any other ideas?

There's a few brands out there for 030 133 064 D.
- £50 - Allcarb, Apriciter
- £75 - Lucas, Intermotor, Vika, Lemark
- £120 - Febi

Anyone got experience with any of these and how they have found them? From what I can tell, there is no gasket, just a ring seal? Correct?