Hard to start gt tdi golf

how cold -39F? like my last poster? (far north in canada)
nobody ever posts location, so can't even guess that.
cold to my wife is 68F.
to my car -40F.(or -40C)

1: check all fuses.?
2: fresh fuel, not a winter car , stored all summer >??
3: ever do the 60k mile tuneup ever? or the 120k or the 180K? as mileage dictates?

This car has EFI and as such, starts in cold weather , super well, like no other
system , ever did (carbs) it knows how to set fuel rates based
on true temperatures, the evaporation rate of fuel is very poor
and very cold weather, so goes very very rich to do that.

my wild guess, is the spark plugs are shot. never checked, or serviced ever... just a guess.

could be an air temp sensor.

have you replaced the fuel filter? this is the biggest cause for these type of problems. one time i have seen the pickup fuel pump go bad though.

Use 5W-30 for cold weather, gives you an easy engine start and good gas millage, in summer time you can use 10W-30.

injectors may be bleeding down causing a loss of fuel pressure making it hard to start,or fuel pressure regulator,sounds like some kind of lack of fuel pressure

hi. i have a mark 5 golf gt tdi the air con doesnt work just had the air con gas checked and topped up no leaks.any ideas.

its normal its because its so cold my 93 chevy does the same

vacuum to blend doors cancels when engine uses it upon acceleration... there is a check valve that could have failed there at vacuum lines to blend doors .good luck

believe it or not but i have seen a intermittant brake light switch cause that.
if you have a scanner monitor IAT ECT FUEL temp,when cold not running they should be with in 5 degrees from one another

Have you had the battery checked..Cold weather is the worst enemy on a battery. They work fine in summer but cold will get em.