Throttle problems

[Nvy]

Hello guys,
I do have some problems with the throttle pedal and i did some stuff to aid it but it didnt work i thought id ask you.

Problems:
1. When i get my foot off the throttle the car would jerk while the revs are coming down.
2. When i change the gears fast, once i press the pedal the car is gone for like 1-2 seconds(like i didnt press it at all) and then the power comes again.
3. Idk if its a problem but its strange behavior - In idle once i press the pedal just 1 cm the revs go up really fast. Never happened in any other car i drove. 1 cm = 3k+ revs, idle is around 900 and drops to 750 at times but goes up to around 900 again, once the revs drop the car would start to shake. The mechanic told me to drive around more and that the IACV can become better with the driving coz the car was stationary for a year. I did some more than 150 kms and nothing changes.

Things done:
1. Spark plugs replaced.
2. TB cleaned.
3. IACV cleaned.
4. TPS checked voltage goes up and down with the pedal press.
5. Throttle cable adjusted - it has a little bit of slack so the idle will not be affected and the pedal has a little bit of free play.

I dont have any other ideas of what to do.

The manifold was replaced with catless one and the two o2 censors were replaced, while this made the things a little bit better, it didnt cure it. I have no engine light on or any errors.

[Joesson]

Did you see the " How to" for cleaning the IACV ?

[Nvy]

Did you see the " How to" for cleaning the IACV ?

The guys cleaned it. In the text above idle valve = IACV. Ill correct it.

[shnazzle]

Sounds IACV-related to me.

Did you remove the IACV from the TB when you cleaned it?
If so, you may not have placed it back exactly right.

[Nvy]

Sounds IACV-related to me.

Did you remove the IACV from the TB when you cleaned it?
If so, you may not have placed it back exactly right.

The guys removed everything from the engine and cleaned it. I think they removed the IACV from the TB too. They said that everything was quite dirty. Is there anything that requires special attention when fitting it back on?

[shnazzle]

Sounds IACV-related to me.

Did you remove the IACV from the TB when you cleaned it?
If so, you may not have placed it back exactly right.

The guys removed everything from the engine and cleaned it. I think they removed the IACV from the TB too. They said that everything was quite dirty. Is there anything that requires special attention when fitting it back on?

Yes. It needs to be fitted EXACTLY where it was.
0.5mm out of spec either way can cause it to either idle high or "hunt". The latter of which seems to be what's happening to you.

It's supposed to be exactly in the middle, but CAN vary. Mine was offset a bit. It was a case of running the engine, lying under it, reaching up and adjusting the position of the IACV until the idle settled.

Best done on ramps.

[Nvy]

Sounds IACV-related to me.

Did you remove the IACV from the TB when you cleaned it?
If so, you may not have placed it back exactly right.

The guys removed everything from the engine and cleaned it. I think they removed the IACV from the TB too. They said that everything was quite dirty. Is there anything that requires special attention when fitting it back on?

Yes. It needs to be fitted EXACTLY where it was.
0.5mm out of spec either way can cause it to either idle high or "hunt". The latter of which seems to be what's happening to you.

It's supposed to be exactly in the middle, but CAN vary. Mine was offset a bit. It was a case of running the engine, lying under it, reaching up and adjusting the position of the IACV until the idle settled.

Best done on ramps.

It doesnt do it all the time and it was like this before. Ill try to read more on the matter.

What about the other stuff with the throttle? Is it worth to replace the whole IACV?

P.S. Ill also try facebook for some help.

[shnazzle]

Sounds IACV-related to me.

Did you remove the IACV from the TB when you cleaned it?
If so, you may not have placed it back exactly right.

The guys removed everything from the engine and cleaned it. I think they removed the IACV from the TB too. They said that everything was quite dirty. Is there anything that requires special attention when fitting it back on?

Yes. It needs to be fitted EXACTLY where it was.
0.5mm out of spec either way can cause it to either idle high or "hunt". The latter of which seems to be what's happening to you.

It's supposed to be exactly in the middle, but CAN vary. Mine was offset a bit. It was a case of running the engine, lying under it, reaching up and adjusting the position of the IACV until the idle settled.

Best done on ramps.

It doesnt do it all the time and it was like this before. Ill try to read more on the matter.

What about the other stuff with the throttle? Is it worth to replace the whole IACV?

P.S. Ill also try facebook for some help.

Hmm OK. What does it act like if you disconnect the throttle position sensor?

[Nvy]

Sounds IACV-related to me.

Did you remove the IACV from the TB when you cleaned it?
If so, you may not have placed it back exactly right.

The guys removed everything from the engine and cleaned it. I think they removed the IACV from the TB too. They said that everything was quite dirty. Is there anything that requires special attention when fitting it back on?

Yes. It needs to be fitted EXACTLY where it was.
0.5mm out of spec either way can cause it to either idle high or "hunt". The latter of which seems to be what's happening to you.

It's supposed to be exactly in the middle, but CAN vary. Mine was offset a bit. It was a case of running the engine, lying under it, reaching up and adjusting the position of the IACV until the idle settled.

Best done on ramps.

It doesnt do it all the time and it was like this before. Ill try to read more on the matter.

What about the other stuff with the throttle? Is it worth to replace the whole IACV?

P.S. Ill also try facebook for some help.

Hmm OK. What does it act like if you disconnect the throttle position sensor?

Can i disconnect and drive it like this? Or you want me to just start it with disconnected sensor?

[shnazzle]

Sounds IACV-related to me.

Did you remove the IACV from the TB when you cleaned it?
If so, you may not have placed it back exactly right.

The guys removed everything from the engine and cleaned it. I think they removed the IACV from the TB too. They said that everything was quite dirty. Is there anything that requires special attention when fitting it back on?

Yes. It needs to be fitted EXACTLY where it was.
0.5mm out of spec either way can cause it to either idle high or "hunt". The latter of which seems to be what's happening to you.

It's supposed to be exactly in the middle, but CAN vary. Mine was offset a bit. It was a case of running the engine, lying under it, reaching up and adjusting the position of the IACV until the idle settled.

Best done on ramps.

It doesnt do it all the time and it was like this before. Ill try to read more on the matter.

What about the other stuff with the throttle? Is it worth to replace the whole IACV?

P.S. Ill also try facebook for some help.

Hmm OK. What does it act like if you disconnect the throttle position sensor?

Can i disconnect and drive it like this? Or you want me to just start it with disconnected sensor?

You can drive with it disconnected.
Avoid busy areas to be extra safe.

You'll feel an initial delay on throttle. That's because the car doesnt known you've pressed the accelerator

[Nvy]

1 and 2 be engine mounts? Im sure these were never replaced on my car. Any ideas how much are the genuine ones?