UK Car Repair: vw golf 1993 1.9 td starting fault., high mileage, typical loss

Question
QUESTION: Over the last few weeks it is taking my car up to 20 seconds to start from cold,i have replaced the glow plugs,had starter checked out,alternator checked out,new battery fitted and carried out filter change inc one way valve fitted on top of the fuel filter.Can you please asist as to anything else i can try or if you require more info. Thanks Lee.

ANSWER: How many miles are on the engine?  It may just be that it has lost some compression and needs the oil splash to build it up. You replaced the glow plugs, did you check to see if they are actually working properly, and to the correct temperature?  This system has to have GOOD connections.

---------- FOLLOW-UP ----------

QUESTION: There is 86k on the clock and all checked out ok on glow plugs. As i said once it has been run for even 5-10 minutes it will run first turn of key. Even when been left for up to a few hours after a good run it will fire ok.

Answer
Well it isn't high mileage but the symptoms fit a typical loss of vacuum in the bores.  The oil film which should remain is draining down, so that when the engine is started after sitting overnight it doesn't have a good vacuum to pull the air in. Turning it over will eventually re-oil the bores and more effectively seal them.  All I can suggest is buying an aftermarket engine oil treatment designed to help this.  You may even try a synthetic oil>