Ford Focus Mk2 1.8 Sport - Ford Focus Mk2 1.8 Idle/running issue - symonh

Hello Everyone, I have receently bought a Mk2 Focus 1.8 as a second car.

It seems to have a slight running issue.

When cold the throttle feels very sensitive, and intially when you press it the revs drop slightly. This makes the car easy to stall when cold. The idle also bounces slightly until the engine is up to temperature.

When warm the car does seem to run ok, but there is still a very slight hesitation when accelerating hard.

So far I have done the following. Changed the spark plugs, read the ECU to see if there are any codes. None were found.

I have checked around all of the hoses and I couldn't find any obvious air leaks

I have also hooked the car up to Torque, the Lambda voltage is around 0.7v (RMS I think), the coolant temp sensor seems to work ok, as does the ambient air temp sensor.

The intake air sensor gave a pretty constant reading of 30ºC, even though I would have expected it to be lower. (Ambient was 18ºC)

One other thing I did see is that the throttle position sensor was reading 13% open even with no throttle applied. I have read that on some cars this is normal but I have no idea if this applies to my car.

has anyone else got any suggestions as to what the problem may be?

I am planning on taking the inlet hose off tomorrow and making sure that the throttle plate is closing properly.

Many Thanks.

Ford Focus Mk2 1.8 Sport - Ford Focus Mk2 1.8 Idle/running issue - FP

This may be irrelevant, but on my Mk2 2-litre Focus there was an engine management software update a few years ago; the issue in my case was difficulty in starting with the engine hot.

Might be worth investigating?

Ford Focus Mk2 1.8 Sport - Ford Focus Mk2 1.8 Idle/running issue - symonh

Thanks for that, I hadn't heard about it.

I will do a bit of research, but certainly hot starting isn't a problem on this car at least.