Engine rev's by itself

1st January 2009, 12:53

sup gang,

the engine on the car went a bit weird yesterday, in a nutshell at about 3.5rpm to 5k rpm I could remove my foot completely from the throttle and find the rev's would loosely hold themselves at that engine speed, give or take 700rpm either side.

Now my first instinct is that the ECU is being a spacker, but then that probably means the Lambda's, ICV, TPS or any other sensor the ECU reads from could be buggered

Any ideas what to check first before I go buying new sensors?

There is NO engine management light coming interestingly enough...

cheers

ads

1st January 2009, 12:57

when this happened we put it on a diagnostics machine, it showed up afew faults.
ended up with lambda sensors and ICV
got them all cheap enough though

1st January 2009, 13:05

Does it ever stall or struggle to idle, On my S the ICV died so it would stall and have sticky revs.
On my old 1.4 the engine would rev by itself, that was the water temp sensor.

1st January 2009, 13:09

funny enough this started happening mine a few days ago.it hunts when your idleing btween 1 and 2000 revs then it holds at 2 when stopped.blit the throttle a few times and it settles down for a few hours and starts over.i cleaded the icv and throttle position sensors but didnt work

1st January 2009, 13:34

map sensor issues can cause the car to rev up on it's own
mine went from idle to about 4k on it's own daily regularly

1st January 2009, 13:35

on my vtr if im parked in neutral and tap the throttle then the revs go to 1200 then goes down to 500 and setles at 700, but sometimes after i tap the throttle it will just keep going between 500 and 1200 automatically up and down. it sometimes also will do this when i come to a stop or put the clutch in whilst driving along, but mainly when i tap the throttle.
what would that be?

1st January 2009, 13:37

hapend to my old 306, only from cold thouhg, the revs shot up to 2k rmp and could go down the road at 30 without doing a thing, changed the icv and lambda and made no difference, crashed into befour i worked out what it was though lol.

1st January 2009, 13:38

Quote:

Originally Posted by NICK2506

on my vtr if im parked in neutral and tap the throttle then the revs go to 1200 then goes down to 500 and setles at 700, but sometimes after i tap the throttle it will just keep going between 500 and 1200 automatically up and down. it sometimes also will do this when i come to a stop or put the clutch in whilst driving along, but mainly when i tap the throttle.
what would that be?

if it continues to do it then it sounds like your icv is shot, allthough if it just does it a couple of times and then settles and doesnt move then its nothing to worry about.

1st January 2009, 13:41

sometimes it does it a couple of times, the other day when i tapped it it just went straight back to idle and sat at that, but sometimes it will just keep doing it till i put my foot on the accelerator and almost kick the revs up out the cycle.

1st January 2009, 13:45

idle control valve? could even be a sticky throttleplate or cable.

1st January 2009, 13:49

yeh may be cable.cos one time when i started my car i put my foot down to rev it as it didnt start first time. took my foot off the pedal and the revs stayed at 2000 where it peaked when i reved it. i then put my foot down to 4000 to kick it out of it being stuck at 2000 but it just stuck at 4000. hmmm

1st January 2009, 14:25

it does it my 1.1 but goes all way 2 redline sometimes, turn it off den back on its fine for about 3week. its my idle valve whats doing it on mine.

1st January 2009, 14:40

Quote:

Originally Posted by spencer_cammedvts

idle control valve? could even be a sticky throttleplate or cable.

Thats what it was on mine. (idle control valve)

1st January 2009, 16:14

mine did this made made a few threads on here. Best advice is to put it on diagnostic (sp) machine see what it comes up with. I replaces loads off censors before i did and wasted too much money lol. Eventually got it sorted.

1st January 2009, 16:32

it turned out to be the coolant temp sensor on my vtr when this happened to it,

quite scary when i was on motorway and easing off the gas but car doing oppisite lol.

1st January 2009, 16:34

first thing id do is remove the airbox and check that its not something like the butterfly sticking slightly, all that is easy to do.

then go down the diagnositc route and get sensors checked

1st January 2009, 17:09

Quote:

Originally Posted by adsayer

sup gang,

the engine on the car went a bit weird yesterday, in a nutshell at about 3.5rpm to 5k rpm I could remove my foot completely from the throttle and find the rev's would loosely hold themselves at that engine speed, give or take 700rpm either side.

Now my first instinct is that the ECU is being a spacker, but then that probably means the Lambda's, ICV, TPS or any other sensor the ECU reads from could be buggered

Any ideas what to check first before I go buying new sensors?

There is NO engine management light coming interestingly enough...

cheers

ads

i had this, still get it back now and then.

But no where near as bad.

Mine turned out to be loose inlet manifold bolts as they can work them selves loose.
Same with the C2's.

Best cleaning all the sensors on the throttle body aswel dude. I also cleaned my map sensor at the same time.

1st January 2009, 17:15

Quote:

Originally Posted by vtss

funny enough this started happening mine a few days ago.it hunts when your idleing btween 1 and 2000 revs then it holds at 2 when stopped.blit the throttle a few times and it settles down for a few hours and starts over.i cleaded the icv and throttle position sensors but didnt work

anyone with this problem have a look at this thread

http://www.saxperience.com/forum/sho...d.php?t=195050

1st January 2009, 18:25

i have all engine sensors if you need any!!

2nd January 2009, 21:09

clean up the idle control valve

2nd January 2009, 21:22

Mine went tits once mate, revved itself silly as I was in a queue of traffic in a busy high street. Rather embarrassing. Disconnected the battery, left it over night, never did it again. Just resets the eeseeyou I believe. Worth a shot

3rd April 2009, 03:21

how did you get on mate?

i had a similar problem happen tonight, first time its happened in 5 years of ownership, thought i was getting away with it lol.

Drove up to the gf's house, no probs, half an hour later we bailed out for a trip to the chinese. Started car and just rev'd itself upto 3k and sat there, hadn't even put my foot on the pedal.

messed about with the revs but kept falling back to 3kish as if that was where it idled, no drop at all. checked the throttle cable wasn't sticking and turned all off again.

Tried again but this time shot up to 3k and bounced about like a nut, reving upto about 3.5k every second, losing the rag at this point cos i was starving and couldnt stop thinking about my chicken fried rice so turned it off again in despair.

"Right!!" i says "this fucker better work" and tried it again...sorted, idling perfect, i looked like i'd just found michael jacksons nose. and on i went to get my grub with a relieved gf, whos genuinely concerned about my welfare cos when things go wrong i lose the plot lol.

would like to have found out what it was tho, wee bugger better not play up when i'm sitting trying to look cool at the traffic lights.

3rd April 2009, 10:07

apparantly its the coolant temp sensor.

I am struggling to find one for a 3 plug as they are different, shitroen were totally clueless when i was there.

Only had them for the single plugs.