Dodgy Reving

[Virtual_Unknown]

my cars been playing up over the last couple of weeks and really needs to go into the garage when i have time but today when i was sat at some traffic lights it started doing something dodgy -
my foot was lightly resting on the accelerator pedal and the engine just started reving itself which it has been doing quite alot, but this time everytime it reved by itself the accelerator pedal was going up and down aswell - any ideas guys?

Joe

 

[viceroy]

Sticky accelerator...check it for wear at the pedal end (loose strands, cable not tightly wound)

If you find anything like that, replace the cable ASAP.

 

[Virtual_Unknown]

the accelerator pedal has always been very jerky and stiff but i didnt think anything about it till it started moving on its own....

 

[viceroy]

Sounds exactly like what happened to my 172 recently...started getting sticky, then the revs started bouncing, then the revs would stick at about 4k rpm...If Id left it any longer it woulda snapped on me.

 

[Virtual_Unknown]

my revs are sticking at 2k - so u reckon its a fooked acelerator cable?

 

[viceroy]

yeah...all the symptoms are what happened to mine...

 

[Paul C]

yep change the cable mate and you will be amazed at the difference!! took me a week to get used to it!!

 

[BenR]

what about if your not resting your foot on the throttle?

and is yours SPi?

 

[Virtual_Unknown]

it still does it if my foots not resting on the pedal - ive just had a quick look, it doesnt do it all the time but once or twice a day

whats SPi?

 

[BenR]

well, if it does it with your foot on or off, then its not your cable.

SPi = single point injection.......

Is yours SPi?

 

[Virtual_Unknown]

i think its SPi mate - its a Mk1 pahse 3 1.4 sport

 

[BenR]

then its your stepper motor going nuts.

Its confused and trying to correct your idle speed. By resting your foot on the throttle its just following the movement of the motor.

Usually a problem with the speedo sender, potentiometer, CTS or the stepper motor itself.

 

[Virtual_Unknown]

cheers mate,

would that also explain why its been idleing at 700rpm and juddering when im driving around 2000rpm?

 

[BenR]

yup, probably potentiometer and speedo sender in that case.

 

[Virtual_Unknown]

cheers mate - cant say ive ever heard of them before but ill make a note of it and let the garage know when i get chance to book her in

 

[beatjunkie]

i got exactly the same car as u i think, and my clutch has gone cos it judders every time i pull away from a junction.what uv sed above mine does that when i turn the steering wheel it revs up and sometimes it revs loads wen i touch the accelerater really gently!crazy renaults!

 

[JAY172]

Your revs should go up (@idle) as you operate the steering to compensate for the load of the pas pump.

rally joe-a few possibilities,

1,stepper moter fault

2,stepper moter signal amplifier faulty

3,throttle potentiometer

4,map sensor