ph1 172 intermittent misfire

[clio_rs]

hi all,

my car seems to misfire when it feels like it at low revs or gear changes and also when i slow down and turn left? it doesnt do it all the time but is annoyin me, about 2 days ago it happened and the orrange engine light come on so i pulled over and checked the fault with my fault reader, it said:

fault 1= p0120 tps/pedal position sensor a curcuit malfunction
fault 2= p0505 idle control system mulfunction

what does that mean and will that cause a misfire??? the car still goes like stink just ever so often misfires for abit.

please help i dont wonna spend money buying thing i dont need too.

 

[benl172]

mine does the same when you put your foot down at low rpm it misses a couple of times then goes.

 

[clio_rs]

yeah if you sit at idle a rev hard it misfires nearly every time. have you investigated teh problem??

 

[GarethM]

could be your coil pack

 

[clio_rs]

ive changed the coil pack, leads and spark plugs.

 

[clio_rs]

anyone else got any ideas what this could be??

 

[GarethM]

could be a number of things tbh

compression test next maybe?

 

[clio_rs]

ive also done a compression test and all cylinders are working fine.

 

[tom130691]

fault 1= p0120 tps/pedal position sensor a curcuit malfunction
fault 2= p0505 idle control system mulfunction
these are the problems! car has to mix air and feul these are where it gets signals from to calculate the mixture needed
take it to a garage n let um sort it out

 

[clio_rs]

a garage will charge the earth to fix the fault if its a part on it way out id rather know without a garage so i can just buy that part.

 

[GarethM]

youll have to get a diagnostic check done, no way of finding out

unless your lucky when you replace something

 

[y0z2a]

lambda sensor?

if the idle control circuit fails, you will normally find it will go into limp mode.

Fuel / Fuel filter?

/y0z

 

[clio_rs]

so how much would you say a good price is for a diagnosic check would be? and can any local garage take this on or does it have to be renault dealers only??

 

[crofty66]

I had mine done for 140 quid. that was with a dyno run at the end. it was a check of all the sensors and a physical check of all leads, coilpack etc and an inspection of the engine. turned out to be a ht lead that was sparking onto the manifold. not cheap but i now know every little fault the car has so i would say its worth it.