Ford Focus fuel starvation
I have a ford focus zetec s 2010 1.8 petrol engine,
I'm having a real issue when driving at a constant speed on motorways travelling at 60mph 70mph etc.....
The car feels as though it is being dragged back then released. I have changed the air filter and sparks and also tried fuel cleaner. But no join as of yet.
Many people I have spoken to say its sounds like fuel starvation, but the car has a built in fuel filter, so not sure when to go with it next ? It's only done 32k miles could if be a sensor or MAF on such a new car?? .
Thanks for your help
The symptoms sound like a fault with the air shut off flap (the Ford term in parts dept) which is also called the intake manifold runner control (IMRC). There are flaps inside the intake manifold which open as the revs get near 3,000 rpm. These are controlled by 2 solenoid valves and use vacuum to operate them. They sit on top of the engine on the side nearest the gearbox. You will see 4 small black rubber pipes coming from the solenoids.
You need to determine if the flaps are broken which will show up one fault code. If the fault is in the solenoids you will get a different fault code. If it is the flaps it is an expensive repair. If it is the solenoids the part costs around (£70+vat from Ford dealer) and takes 5 mins to fit.
So you need a diagnostic check to find out.