Throttle position sensor issue?

[gort]

Hi all

Ford Focus Mk1 1.6.
Can a faulty Throttle Position Sensor cause the rpm to increase when moving in neutral in the period of wanting to go up or down a gear?

I ask as if I'm in a gear at say 2000rpm and put the clutch pedal down, in that period the rpm creeps up, where as before it would immediately drop.

As a test I coasted at 25mph from 3rd gear and the rpm kept creeping up to over 3500rpm until I had to brake and drop down a gear.

A new Idle control valve was put in recently due to some rough idling and cold starts but no issues with starting or idling now. When stationary and I rev the engine it immediatly drops to normal idle rpms. Possibly crap replacement ICV?

I've tried an OBD scan and no errors are coming up.

However, a new sensor is a tenner so might just try a new one anyway.

Ta

 

[gort]

Thanks all, think I sorted it, however to answer the questions, possibly to help anyone else in a search in the future......

I'd be looking at the clutch switch potentially, by coast are you referring to having the clutch down whilst in gear? Or selecting neutral and clutch up?

It was either, coasting with clutch up or down.

Do revs increase or just hold? Could be a sticky throttle body.

Revs were increasing but I didn't see what limit, just that it was at around 2000rpm and crept up to around 3500rpm and stopped it there.

FIX:
I had a hunch about the new ICV installation.
I did one years ago myself (2 min job) and reset the ECU to make the new ICV learn the engine.
I disconnected the battery for a while to do the reset, let the car sit at idle for a few minutes and it sorted out the whole issue. A few test drives and around 40 miles of driving later, the issue appears to have gone.
So I'm guessing the garage didn't do this reset and as such the rpms was so erratic?

Got a spare TPS now if anything comes back and could swap that of need be. Fortunately that's also a 2 minute job as it's right the front of the engine bay on the throttle body.

My chariot lives another day!