HI Guys.

I have just brought a focus 55 ghia, its was all going well for the first few weeks, but now it randomly doesn't start.

All the electrics come on and the engine sounds like its trying but it just doesnt start. usually if i stop and try again it will start 2nd time, however the radio DAB wont work. The DAB is wired in the the headunit adapter (ignition live i think). If i turn the engine of and start it again everything works (including DAB).

I have read lots of posts and checked the wiring and most of the fuses but all looks okay. All the pipes look fine and secure.

I have plugged it in and It had a fault code of "U1900, 60" But it seems like a bit of a hit and miss code. There is no other fault codes, battery voltage is ok (same as my brothers 09 focus).

I have changed the spark plugs, the ones that come out where rusted (v Badly) and must have been in for years.... the replacements wouldn't start it, so I had to get another set which then started the car.

I have put redex in the fuel ( once need to do a second time next week) but its still doing it.

Does any one have any ideas on what else I could check? Could it be the aftermarket headunit? could it need another set of spark plugs?

Thanks!

First are the plugs gapped correctly?

Is there still corrosion present around the plug holes that may be reducing conductivity?

I'd check that then maybe look at new HT leads and maybe even a new coil pack.

Eliminate the electrical side and work from thrre.