Hi there,

I have a 2004 Ford KA which doesn't like hot weather. It will start from cold fine and drive fine as well. But if I park it up for any longer than 10 minutes on a hot day, it will really struggle to start, seems to be worse the hotter the weather is. It will still do it on cooler days just not as bad. I have changed the oxygen sensor which made no difference. All I can think of is the idle control valve but it looks like it's a pain to get to! If I start it with say a 1/4 throttle it starts perfectly.

Poor Starting:

Really Poor Starting, here it was taking ages to start, but as soon as I touch the throttle it starts straight away:

Good Starting But Dodgy Idle, as you can see after a while it picks itself up:

How It Should Be:

My Ka has been doing this for ages so if anyone has any ideas please let me know,

Cheers,

Ben

Have you tried cleaning the throttle body? It may be a pita but is it not better than worrying about other problems it may be?

Have you checked your spark plugs? (Assume its a petrol?)

Have you checked your air filter?

Fuel filter?

Coil pack?

The fact it's related to the temp of the engine rules out a few of the above but it won't hurt it to give it a good overall service whilst troubleshooting

idle control valve will be a good one to clean as a simple job to do. also change plugs leads and air filter as previous poster said.

always do the simple things first.

Cheers for that, I did service the car last year but still did the same thing, didn't do the leads though so I'll get them changed. Also my idle control valve looks like it's under the intake manifold so it looks a pain to get to. Throttle bodies easy though I'll clean that out.

it's the same on my boys fiesta the idle valve. you can get to it easy enough with a small socket if you have small hands or can pull some of the wires and pipes out the way. the idle valve sticks and when ticking over it keeps revving & losing revvs (irratic) if its not doing that then it maynot need touching. if it in doubt clean it with brake cleaner or wd 40 .

Try cleaning the MAP sensor.