Hey,
I noticed that when i put the car in neutral whilst the car is still moving, the engine revs automatically. when the car is in gear it is as if i have my foot on the accelerator but in actual fact i don't and the car still moves. i dunno if something with the sensors or accelerator? please can you help me?

how far up does it rev? if your in traffic for example moving slowly with the clutch up the revs will flick up about 100rpm tops if you dip it, also its actually possible on a flat bit of road to get a punto through the gears from a standstill up to 5th gear without using the throttle and not stall it. Also if its not as simple as that the guys who would know more would need the mark of your car and engine type

most probably the ICV... the ICV controls the engine speed when your idling (i.e. whenever you foot is off the throttle.)

ICVs are contained within the throttle body and can't be renewed seperatly - you'll need a throttle body from a known good engine unless you want to speed £300+ on a new one

mk2 punto?

i have a 1.2 8v MK2 model. i changed the oxygen sensor at the front of the car and then cleaned the carb. the car is kinda sorted but at times u can still hear it reving. i dont know how much it revs by cos i dnt hv a rev counter but i would say about 1000rpm. i just hope this problem corrects itself!

depending on year there was a issue with the TPS.

someone mentioned it could be the new air filter i recently installed. if i replace the old one, do you think it would make a difference and hopefully work as normal?

could possibly be. id give it a go - it wont cost you anything

iv installed the original air filter back in but the car still revs and cuts out when in neutral for to long. should i try and get the car into a habit f breathing in air through a different filter? does anyone think in time it would sort it self out?

try reset the ECU - disconnect the negative terminal and leave it overnight

within a couple of days, it should be running smooth if thats the problem.

kk il give it a go. do you think the problem is to do with the new air filter i installed? or just one of those things?

no such thing as 'one of those things'....something is causing it.

T14086 said:

no such thing as 'one of those things'....something is causing it.

Click to expand...

yea if only things fixed them selves our job would be so much easier

as said only thing that can cause revving are tps and icv

and there was a service new about the tps sensors a wile back

This could be a million miles off but the first post describing the problem reminded me of exactly the same problem I had with a Ford Sierra about, er crikey, 20 years ago.

It was a company car so the dealers saw it regularly and never worked out what is was. Very noticeable in spring and autumn and always went away after a 6k service and returned about 3k later.

After several years and about 90k miles I bought the car for next to nothing and decided to investigate the problem myself. It turned out to be a very thin vacuum pipe between the carb and the block - something to do with early emission management stuff. It as often trapped under the air filter housing when it came back from service - the tube was only just long enough for the job.

But the real problem was that at the block end the 'fit' involved 3 section of increasing size rubbery hose to match the tube size to the connector on the block. This could work loose, compromising the vacuum at tickover, but with out falling off or even appearing to be loose.

Once I fixed that the car was thrashed for another 20k+ miles in the next year with no recurrence of the problem at all.

I have no idea if there is something similar on the 8V - never needed to look at ours yet - but if there is it would be worth checking. In fact anything that might be subject to loss of vacuum effect.


Grant

thanks for that. i can kinda relate to it in a way.

Could this problem be caused by a faulty throttle body or lamba sensor, ( see 'errativ revving' thread on the punto forum .