Hi

Apologises if this is the wrong place for this but I do need some help

I have a Ford Focus ST170 but i'm having problems with non starts. It's been in the garage two times already. The first time I had a non start I unplugged the fuel pump fuse plugged it back in again and jump started the car to get it running, however an Engine Management Light came on. I took it to the garage and they carried out an electrical Management System Test which revealed the fuel pump driver module was offline which may have been caused by low power supply from a flat battery. They also carried out a battery and alternator test which came out as ok. There is no reason for these to be the problem as both the battery and alternator are less than a year old including the terminal wires. So they cleared the fault codes and road tested and all is fine for a day. The following morning another non start back to the garage. So they confirmed there is no new fault codes and nothing is wrong with the battery and alternator. They carried out an Engine Compression Test and revealed its between 100-110psi when it should be over 160psi. They concluded that it was possibly bore washed and introduced a small amount of oil to the combustion chamber and left over night. The following day they fitted new spark plugs and it worked again for a day. The following morning another non start! What confuses me is how can it work fine for one day each time yet on three separate occasions in the space of a week be followed by a non start the following morning. Each time it's ticking over and sounds like it wants to start however isn't. I would love some advice on the issue because each time this is happening its costing Cheers

Could be a faulty fuel pump control module? Especially if its coming up with that being at fault but the usual cause of that (battery/alternator) is ok. Either that or possibly the pump itself.

Yea that's what I thought, i've had this sort of problem before but usually taking the fuel pump fuse out and putting it back in trick has worked. Cheers for the reply anyways

Is it original Ford spark plugs that are fitted by the way? Ive read about non Ford spark plugs apparently frying the ECU and causing a similar fault?

Yea original Ford spark plugs this fault has been occurring before they were replaced. My biggest fear is that because the car was bore washed this is going to be a repetitive problem that may eventually lead to an engine rebuild or something ridiculous.