Looking for some advice regarding my Focus starting issues.

2008 (57) 1.8 TDCi with 81000 on the clock

Few issues been happening for a while

• Engine runs quite rough and is fairly noisy
• Slight shudder when running idle
• Puff of black smoke when putting the foot down

The car was running ok apart from these issue and had a slight burning smell from the blowers then one night it just wouldn't start. Engine turned over but it was like no fuel was getting to the engine. Left it overnight, went to check next day and it started fine. Took it into a local garage, they said the fuel injector seals were burst which was the source of the burning smell also. Replaced these, done a service, replaced the battery and it seemed fine for a while.

Every now and then the car now takes 5 or 6 seconds to fire up. Same as before, turning over but like a lack of fuel getting to the engine. After persistance it does start and goes fine. Normally this will happen first thing in the morning.

Can anyone advise what it could be? Fuel pump, fuel injector etc. Spent £400 on the car already and would like to try keep costs to a minimal.

Thanks in advance.