Ford focus rs går ojämt

[MikaelRS]

Har en Ford focus rs 2009. autotech trimmad.
För några mil sedan så går den ojämt när jag ligger på samma varv.
Det känns som om man skulle släppa lite på gasen hela tiden.

Någon som vet vad det kan bero på?

[dannemare]

Har en Ford focus rs 2009. autotech trimmad.
För några mil sedan så går den ojämt när jag ligger på samma varv.
Det känns som om man skulle släppa lite på gasen hela tiden.

Någon som vet vad det kan bero på?

Jag hade ett liknande problem när min IAT/MAP-mätare var defekt. Har skrivit om det på focusrsoc.com: http://www.focusrsoc.com/forums/topic/1 ... peratures/ :

I'm using a DashDAQ to monitor various values, including inlet air temperatures (IAT).

However, during the past two months the registered IAT has gone up, up, up (gradually over time).

Back in April it would typically tell me IAT was around 30C when it was 20C ambient temp. Fair enough.
This morning it was around 20C ambient temp as well, but the DashDAQ claimed an IAT temp of 54C !! And this is even before I started the engine! Even if the RS has been sitting in the garage for 2-3 days, it claims IAT to be around 30-40C higher than ambient temp.

A month ago it would typically say "only" 15-20C higher than ambient temp after sitting in the garage over night, but after a couple of trackdays the past few weeks (where the IAT value went up a fair bit to around 50C), it has simply just stayed in that temp region.

Has anybody else experience similar from an OBD-II tool?

Okay, so today I went on with changing the IAT sensor. It was 19C ambient temp. In order to have a before value to compare with, I switched on the electronics in the car without starting the engine. Then I switched on my DashDAQ and it showed - hold on! - 83C.

Switched it off again and started working on the car. I had already removed the two undertrays the other day so it was just a 5 min job to change the sensor itself.



Switched on the electronics again as well as the DashDAQ. Almost couldn't believe my eyes! It was now reading 19C. Same as ambient.

Took it for a little drive and all was fine. No stupid readings anywhere to be seen. Thanks once again, Smoky, for mentioning the sensor as a possible source of my problem.

On a side-note (already mentioned in another thread but should really be added here as well): When I was running with the faulty sensor, very often - on cold starts - the standard Ford oil temp gauge and oil pressure gauge did not work. I always had to switch off the engine and start it up again 5-10 minutes into my commute to make the gauges work. After changing the sensor in question, this hasn't happened since. Weird...

Finally, I experienced "erratic" boost behavior in the past during fairly steady highway driving where the boost would come on/off/on/off with the slightest change in engine load (road going slightly uphill, for instance). Haven't seen this issue since I changed the faulty IAT/MAP sensor.