So i have a few problems with my VY, that at a guess are related. Firstly it has started revving at much higher rpm than usual in idle. Generally at around 1500 rpm. This drops to around 900 in reverse. Secondly when cruising along and you take your foot off the accelerator, say for example to start slowing down coming up to a set of lights, there is virtually no slowing of the car at all. Gear changes are at times rather jerky. Also when you go to take off from a stop it pretty well takes off where before it would hardly move. Any suggestions to what might be wrong would be appreciated, but im guessing there is something wrong in the transmission.
I don't think there's anything you have described effected by the transmission , it's taking off faster due to the elevated revs at idle. It could be 1000 things but it's ain't the tranny in my experience, maybe ask google but probably lims, vacuum , throttle, filters ect
It's also not slowing because the transmission is changing on revs, yours are too high for it to down shift as it should. Possible timming issue also
Should add, that i recently replaced throttle position sensor, as before idling it would rev high ever so breifly and feel like it wanted to lurch forward. Still does that occassionly but rarely. That was a few weeks ago now. This has developed over the last few days.
I wish I could be of more help in diagnostics as I'm fairly new to post 90s cars, but however from similar issues in different cars I have come to a pretty fair certancy it's not the transmission. It may be worth paying for a quick diagnostics too, sorry I couldn't be of more help
All good. the imput is appreciated. I was told by a mechanic once when i had a different issue however that theres no point running a diagnostic unless the car throws a fault code. Not sure how true this is, but im not getting any fault codes. Would have thought that a mechanic could have a look at certain readings and potentially see an issue. But i could be wrong
id go find another mechanic then if all he wants is fault codes to fix, you can still run a scanner of it and if you know what to look for you can check plenty of things, watch the TPS % and voltage as you move the throttle blade and make sure it's smooth, make sure it's around 0.45 - 0.50 volts with no throttle, otherwise it may do what you describe.
When i installed the TPS i when standing at the front of the car rotated it in my hand anticlockwise towards the battery until the slot lined up with the adaptor. I then slide it on and then twisted it back towards the passenger side until the screw holes lined up. Is that the correct procedure ?
that's fine though if the stop screw isn't adjusted properly you might have high or low idle. hence checking with a scantool or multimeter, also checking the IAC valve steps is a good idea if you have a scantool on it. You can also do it all yourself with a laptop if you want, you can buy the ALDL usb adapters here and the software is free, you can scan fault codes and will be able to see the TPS voltages, % and IAC steps. http://pcmhacking.net/forums/download/file.php?id=10930 pcmhacking.net - View topic - FS: USB ALDL Interface
Yeah you can buy Bluetooth compatible ones that go one your dash and give you a heap of readings right there. If anyone with tuning aspect had a look they could tell you where the issue was comming from, I would agree to get a second opinion.
Wondering if i need to install the TPS in the opposite way i did. as in clockwise past attaching screws and twisting back towards battery until they line up ? would this make a difference ?
no will only go one way. Just keep in mind Bluetooth ones are likely OBD2 which isn't going to work in VY V6 and older.
So i thought i was getting on top of it. Found oil was low, so i topped it up and it ran alot better. cleaned maf sensor, shook out the air filter, and cleaned the throttle body. Was behaving fairly well. Now it does it nearly all the time. However a few quick pumps of the accelerator and revs come down to normal and it behaves and runs ok. I am beyond what is wrong. I have had a fault code come up this morning so i hope this sheds some light and isn't an unrelated problem. Was hoping somebody might have a clue rather than forking out for a diagnostic.
the idle speed is set in the tune, it's auto adjusted by the IAC valve, unless you have a vac leak which then the IAC Valve can't control the idle speed as it will be out of range.
I did think to myself it sounds like cable might be getting a bit stuck, but im not sure now as the revs have also being pulsating until it settles down. Seems worse when cold and seems to idle fine after its had a run and up to temp. Engine does sound a bit funny like it has an airy sound. So yeah guessing it may be a vacuum leak.
