Hi there,

I have been encountering a few problems with my 1998 MK4 Fiesta 1.4 zetec.

Firstly, i cannot get the idle speed to drop below 1000rpm, i have fitted a new idle valve and engine coolant temp sensor but has made no difference. I also replaced the throttle position sensor but to no avail. The car had a recent full service using 5-30w oil, new coil leads and plugs.

Another problem, which may be related to the first is once the car is warm pulling up at junctions causes the revs to rise to about 1800-2000rpm for about 5secs and then it returns to idle. Also, at some times the car will rev to 3000rpm before dying and being a nightmare to restart(flooded?).

I have replaced the power steering connector and wiring as that was broken when i bought the car.

I am starting to lose my patience in soughting these probs out, can anyone help?

 

Air leak perhaps?

Was your idle valve new or a 2nd hand item?

 

check a switch under your clutch pedal. this causes the revs to rise when the clutch is engaged.

Make sure its in the holder properly.

 

Idle valve was new from ford.

Checked all hoses, inlet manifold & throttle housing seal seem good to.

I am starting to suspect the vechile speed sensor that sits on top of the gearbox

 

have bleeped the clutch position switch out on a multimeter and it seems to be working fine. Will check its in its holder properly tho, i suppose the holder may have been bent from a stray size 10 also.

 

haha theres been loads of posts like this on UK FIESTA NETWORK and they all seem to be that switch, also ive had mine, brothers and mates do this due to that switch.

 

these fiestas seem riddled with electrical problems. this has been the most unreliable car i have owned. i thought buying a fiesta was a fairly safe bet.

i checked the switch and all seems fine. the revs rise to just under 2k when the clutch is pressed or you put it in neutral then take ages to drop to idle. a speed sensor is going to be over £80 with vat so a little apprehensive on buying it if unsure will solve problem.