Hi all, I have bought my better half a 2000 1.8 petrol focus as her first car and I am having a few issues. The car runs great when cold but when it starts getting up to temp' the problems start. It will idle around 600 rpm and miss as it is stood. Also when driving anywhere between 1 - 2000 rpm it is down on power, coughs and judders. As soon as you get above 2000 rpm it starts to behave itself. I have changed the HT leads (after getting a shock off one) and plugs. I also found a split PCV hose which I replaced. I have had a look at the MAF sensor and it looks very clean. Any ideas would be great, unsure if there are any methods for testing the MAF with a voltmeter just to make sure?

Many thanks.

 

have you had it scanned for any fault codes?

 

I scanned it and got P0113 & P0171. I checked again today and nothing has come back.

 

Unplug the MAF and take it for a drive. Engine light will come on so you will need to reset it after.


Have you changed the coil pack? Pretty common failure on the zetecs.

 

What do the codes mean?

 

Just took it out without the MAF connected and it was just as bad, I noticed today that the scanner has the Oxygen sens & Oxygen htr showing as INC instead of ok.

 

Sorry mate

P0113 - Intake Air Temperature sensor 1 Circuit High

P0171 - System too lean Bank 1

 

Well I took it for a spin this afternoon to see if I could get any error codes to show and the speedo cut out until I switched it off and back on. Could this be linked to the rough running/idle? Possibly Vehicle Speed Sensor?

 

They do lose a bit of oomph when the vss messes about. Well mine did.

 

The strange thing is that it seemed to run much better when the speedo was out.............give in!

 

You really want to be reading the live data from various sensors to see what is going on. Sometimes handing it over to a specialist to diagnose will work out much cheaper than chucking parts at it hoping it will solve the problem.

 

Bank too lean is probably the hose under the inlet manifold that goes to the breather/inlet manifold

About £20 from Ford

 

They perish/split. Took me a while to find it!