jertum Posted July 15, 2014 Share Posted July 15, 2014 Hi all, back again with yet another problem. I have a 2002 Fiesta Finesse 1.3 (Early mk6 shape) While the car is stationary, it continuously revs itself up and down - from 1000 to 3500rpm - making me look like a complete a**ehole boy racer at the lights. The trouble is, when I put the car in gear, the revs are totally unpredictable and can cause the car to shoot forward when lifting the clutch - quite dangerous I'm sure you'll agree. Also, when accelerating, if I lift off the accelerator pedal it can take up to 2 seconds to recognise that I have - causing it to continue accelerating after I've taken my foot off the gas. I have had problems with the car cutting out when idle/slowing down at junctions before but cleaning the throttle body seems to have cured this. Any ideas? I'm clueless when it comes to cars but a quick Google points to a possible problem with the throttle position sensor? Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 15, 2014 Share Posted July 15, 2014 sounds like a throttle issue, either a potentimeter issue or Throttle Body itself. Quote Link to comment Share on other sites More sharing options...
mick85 Posted July 15, 2014 Share Posted July 15, 2014 Yeah agree wit James potentiometer most likely culprit Sent from my iPhone using Ford OC Quote Link to comment Share on other sites More sharing options...
stef123 Posted July 15, 2014 Share Posted July 15, 2014 Idle control valve is where I'm putting my money Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 16, 2014 Share Posted July 16, 2014 I completely missed the word "Stationary" in the description, but having re-read it, I am now more inclined to agree with Stef as the first option, then mine might be a second look! Quote Link to comment Share on other sites More sharing options...
jertum Posted July 16, 2014 Author Share Posted July 16, 2014 Thanks for your replies - much appreciated. I should probably mention that it seems to rev high when pressing the clutch between gear changes too; something that I only noticed last night. I managed to get a video of it doing its crazy idle revving, please see link below. Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 16, 2014 Share Posted July 16, 2014 Definately seems to be ICV related. If you have a Haynes manual I suggest you remove and clean the ICV (Idle Control Valve) Quote Link to comment Share on other sites More sharing options...
jertum Posted July 16, 2014 Author Share Posted July 16, 2014 We've already cleaned the ICV, I guess the next step is to replace it altogether. Would this explain the throttle 'sticking' when the car is in motion? There's a 2 second delay between me taking my foot off the throttle and the car recognising that I have done so. I gather there is no throttle cable on these cars, meaning it is controlled by some kind of sensor. The mechanic I've taken it to has sourced a whole new (used) throttle body, including sensor, which he's going to fit to see if this solves the problem. Quote Link to comment Share on other sites More sharing options...
mick85 Posted July 16, 2014 Share Posted July 16, 2014 Throttle potentiometer give hassle on them Sent from my iPhone using Ford OC Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 16, 2014 Share Posted July 16, 2014 As mick says, the potentimeter is the culprit for throttle stick but if you cleaned the ICV then its worth looking at the tedal assembly. Quote Link to comment Share on other sites More sharing options...
jertum Posted July 16, 2014 Author Share Posted July 16, 2014 Excuse me for being a bit dim, but what is the potentiometer? Is this the same thing as the throttle position sensor? Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 16, 2014 Share Posted July 16, 2014 Potentimeter is the sensor on the pedal that translates how heavy your foot is, to a signal to the throttle body. The throttle body takes this signal and conveys it to the PCM to say "we want to go this fast" and then the PCM works to deliver the power. Your best and cheapest bet is to find a used accelerator assembly kit and fit it to your car, if its the sensor as could well be the case, its a cheap fix, undo the old, on with the new and hopefully no more boy racer appearance :p Although I must say, if my car was revving like that I would have to look at the neighbour in the car next to me with a panicked face mouthing "its trying to kill me!" 2 Quote Link to comment Share on other sites More sharing options...
mick85 Posted July 16, 2014 Share Posted July 16, 2014 It's on throttle body little black sensor Sent from my iPhone using Ford OC Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 16, 2014 Share Posted July 16, 2014 I was under the impression that the potentimeter was on the pedal as well and the reciever on the throttle body assembly? if that is wrong Mick, what is the sensor on the pedal? Quote Link to comment Share on other sites More sharing options...
jertum Posted July 16, 2014 Author Share Posted July 16, 2014 If you're both correct, could this mean that both the potentiometer and the throttle position sensor have failed or possibly just one of them. I guess it's a case of trial and error really. When I bought the car, the EML was on for a failed lambda sensor. The dealership fella replaced the sensor before I picked up the car and the EML has not appeared since. He actually gave me the old sensor as proof that the work had been carried out. Now I'm wondering if he just removed it. Could this cause any of the problems I've had? I've no idea what the lambda sensor actually does. Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 16, 2014 Share Posted July 16, 2014 lambda sensor is part of the emissions monitoring, As for the sensor, it could be either the potentimeter or the TPS sensor is duff, but I dont know the correct way to distinguish which is most likely at fault. I would say if you can get a pedal assembly cheap then its always worth swapping it over. Quote Link to comment Share on other sites More sharing options...
mick85 Posted July 16, 2014 Share Posted July 16, 2014 Potentiometer measures position of throttle flap throttle position measures position of pedal Sent from my iPhone using Ford OC Quote Link to comment Share on other sites More sharing options...
jeebowhite Posted July 16, 2014 Share Posted July 16, 2014 D'oh, had the two the wrong way around! Quote Link to comment Share on other sites More sharing options...
jertum Posted July 16, 2014 Author Share Posted July 16, 2014 Is the throttle position sensor built in to the pedal mechanism itself, or is it attached to the throttle body? Don't suppose anyone has a link to an image of the location of the TPS? Cheers Quote Link to comment Share on other sites More sharing options...
kevzs960 Posted July 16, 2014 Share Posted July 16, 2014 Had a similar problem on myn. But when i slowed down (brake an clutch down to pin point fault) my rpm would drop to about 200-300rpm. And i had to blip the throttle to stop it from dying on me. Turned out to be the throttle body. They got the tps built in. Replaced it, reprogrammed me pcm (ecu) to my driving style an worked a treat Sent from my GT-I9195 using Ford OC mobile app Quote Link to comment Share on other sites More sharing options...
jertum Posted July 16, 2014 Author Share Posted July 16, 2014 Yep - sounds like mine. My local mechanic is in the process of sourcing a replacement throttle body so hopefully that'll sort it. Did you go to a specialist Ford place to get your ECU reprogrammed or just do it yourself? Quote Link to comment Share on other sites More sharing options...
kevzs960 Posted July 16, 2014 Share Posted July 16, 2014 I work at a ford garage so done it myself lol changed the part within warranty so it didnt cost me the 300+ quid lol. You dont have to get it programmed. I just done it to suit my driving style cus i was sick of the mpg figures i was getting. They were around 25ish. An after i was gettin 30's an thats with a led foot Sent from my GT-I9195 using Ford OC mobile app Quote Link to comment Share on other sites More sharing options...
paul_focus Posted July 16, 2014 Share Posted July 16, 2014 Think the best thing to do could be to plug a diagnostics device into your car and see what it comes back with that way it will find what is causing this problem and tell u what sensor need replacing Sent from my iPhone using Ford OC Quote Link to comment Share on other sites More sharing options...
kevzs960 Posted July 16, 2014 Share Posted July 16, 2014 If the eml isnt on then it might not produce a code. The flucuating revs still might be within tollerence for it to not produce a dtc. Its abit of common knowledge an gettin help iff my master tech that faulted my part. As long as its duagnosed by a technician then you wont be chucking parts at it Sent from my GT-I9195 using Ford OC mobile app Quote Link to comment Share on other sites More sharing options...
paul_focus Posted July 17, 2014 Share Posted July 17, 2014 Most diagnostic machines can read sensors and things with out the EML light been lit Sent from my iPhone using Ford OC Quote Link to comment Share on other sites More sharing options...
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