i recently replaced a fuel pipe on my car and now it likes to sit around 1500rpm but does drop down but is still on the 1000rpm mark

i have cleaned the MAF and also cleaned the ISCV out and reset the ECU
does it take a few miles for the ECU to re-learn as i have done around 16 or so since i cleaned these parts.
could it be an air leak somewhere but how do you test this if all the pipes are tight and there is no sign of damage

any help mucho appreciated

 

Do you mean it's just at 1500rpm when cold, but drops to 1000rpm when hot ?
Resetting the cu can take a few miles sometimes up to 100, as it learns from varying conditions.
tabetha

 

thanks for the reply
sorry didnt really make my question that clear lol

the car seems to be hanging at around 1500 when it is fully warmed up but it will drop when i come to a halt eventually but not straight away
other than this there is no difference in performance and it doesnt seem lumpy in any way
someone has said could be the butterfly in the throttle body sticking and need resetting by loosening the 2 screws in there and snapping shut a couple of times, the TPS needing a clean or even the temp sensor near the stat housing playing up

 

It's none of those things, most likely it is a duff speed sensor, these give a reading to the ecu when you are above a certain speed for better gearchanges they keep the revs around 1500 whilst changing, if one is duff it is having to wait for other info that it is actually stopped and idling, if you stop quick enough you can catch them out as well.
tabetha

 

cheers for that

sorry to be a pain but any ideas where these are located on a Fiesta Si?

 

No clue on SI sorry.
tabetha