Ford Focus idleing issues - poss ECU Update required??

atrixblue.-MFR-.

ukjoel wrote: »

Sorry to hijack thread but was wondering would this problem be picked up on a diagnostic machine. I am having a similar issue - air con pump just replaced and now getting bouncing revs and stall when car is slowing down or stopped in neutral.

Dealer says it wont produce a fault code (or very unususal to do so) but warranty company wont repair without a fault code.

Thanks

faults being picked up by diagnosyics machine's will depend on the equipment used and software, some read the stored codes while others can do much much more like live reads of the ecu while the engine is running most common readers will only read the ecu while the engine isnt turning over, but ignition on.

suffice to say that if idle problems are apparent then a code of some sort should appear, but not necessaraly bring on engine managment light.

as said there are a number of things that can cause these problems.

air mass (air flow) meter.

map sensor.

egr valve (if fitted depending on vehicle engine type)

idle speed control valve

throttle position sensor,

throttle housing itself.

throttle housing gasget leaking air.

injection manifold leaking air from gasget.

injection manifold has a crack leaking air.

oil breather hoses split, cracked, loose.

servo hose leaking air.

then if none above.

faulty injector.

faulty fuel pressure regulator.

faulty fuel filter.

faullty fuel pump.
faulty fuel line non return valve (a valve to stop fuel returning to tank and de pressurise the fuel rate.

fuel filler cap seal broken. (petrol cap)

cam sensor.

crank sensor.

timing.

faulty ignition coil pack.

faulty ecu.

faulty battery

faulty alternator

there is a huge list of possabiltys. most of them will give a fault code.

emma.b123

Just a quick update - ISCV replaced and seems to have solved the stalling problem. The idle still seems a bit on the low side, but I think maybe I'd been used to a higher idle with the cracked hose, it may actually be correct now!?
Still no update on the constant running AC/Cooling fan. I'm getting a second opinion from another local garage this weekend before taking it to the stealership!
Still no codes being thrown by the OBDII or engine management light, so guess that's another wait and see job...