2007 focus duratec idle hunting and no power.

[jasnae]

Hi guys, I will try to keep this simple, I just bought a supposedly water damaged 2007 focus, car is running but hunts badly between 500 and 1000 rpms. Only does tihis after about a minute. Car drives but has no power under around 2500 rpms, when free revving it is sluggish. The previous owner had it at a mechanic that stated the engine timing was out by 5 degrees, he apparently rectified this. The previous owner also had the car at a ford dealership to try to resolve problems, they have reolaced the ECU, throttly body and accelerator pedal assembly. they were unable to get it running right and advised replacement of all wiring looms. I replaced the intake manifold and wiring harness today and still exactly the same. I dont know if there has been any internal damage from the water, compression is 195 on all cylinders. Need some help, i guess next step is to remove the head and inspect the internals. seems more electrical though,
Cheers,
Jason.

[marg99]

was the timing belt replaced to cause the timing change or if not is it slipping? I cannot recall if this motor has a rubber drive cam belt

[jasnae]

Timing chain in these, checked timing, all seems fine there. Checked codes today, showing p1018 throttle position sensor. All seems to check out ok though. Still scratching head.....

[marg99]

hunting usually suggest an air leak but not usually with significant power loss

[20focus05]

Have you checked the resistance values of the TPS?
Or plug diagnostics tool in and look at live data.
Check if it has a nice resistance/voltage change, no spikes.

Fuel filter blockage, water in fuel.
How bout the exhaust system? Rust blocking things mmm but that would pull you up at about 3000rpm

So all vacuum lines have been checked?
Silly question I know, cause the PCV under the inlet causes a few headaches.
Compression seems good. So would suggest internals are ok.

[jasnae]

Thanks for the replys, ended up replacing the engine, out of desperation pulled the original motor down, head gasket was leaking into number one, had 3 original pistons, but number 3 piston had been replaced with a forged piston for some unknown reason. did the engine swap last night and all good.
Does anyone have any idea in regards to Fault code P0720, appears to be a speed sensor fault code, where is the speed sensor in a 2007 focus.
Thanks.

[marg99]

the speed sensor is down on the back of the transmission housing next to the drivers side axle

[jasnae]

Had a look at the old engine setup, the only sensor on the gearbox is the reverse light switch, I'm sure that neither the old or new drivelines have any other sensors in the gearbox. it has two abs/speed sensors, one on either wheel, does the speedo take signals from these?

[marg99]

The speed sensor is located on the transmission on top of where the axles come out of it. It's a tight spot to get to.
you need car up on a jack (with stands) as it is on top of where the axle comes out of the transmission housing sorry about poor picture

[jasnae]

Thanks for the pic, the 2007 definently does not have a speed sensor on the gearbox, the location in the picture is blanked off in both my original set up and in the 2008 donor car, I am guesing they changed to reading all info off the wheel sensors. I have replaced the sensors with the ones from the donor, still no speedo. I might just swap the compete hub assemble over to eliminate any issues there. Thanks, appreciate the help.

[jasnae]

Just incase anyone has any brilliant ideas, I replaced all 4 wheel speed sensors and hubs off the donor car today, still having the same problem, no speedo, power steering fault coming up on dash and code P0720. Car is running and driving perfectly though. Running out of ideas, Ford replaced the Ecu with a donor Ecu the previous owner supplied, could the ecu be form an earlier focus and looking for a signal from a gearbox speed sensor that my 07 Focus does not have? any ideas would be great.