Very rough start now when outside air cold

[eddfive]

2005 F-350 6.0L turbo diesel, Use to start with no issue in cold weather. Started okay at a -15 degrees a year ago. Now once temps get to 25 really struggles to start. I almost wear out the batteries to get it to start. At 40 degrees it starts fine. Once started it runs good and will re-start all day long. First start in the morning is an issue. If I plug it in it will start just fine as well. I have changed glow plugs and this did not fix the problem. Could it be the glow plug relay? I hope the PCM has not done something weird. Any advice would be appreciated. I am new to the forum and live in Texas so it really does not get that cold.

[kx592]

Try the relay and maybe its time for batteries or alternator

[RobertJory]

My 04 does exactly the same thing. Couldn't get it started this morning 21 degrees.

[kx592]

You fellas every do two or even three cycles of the WTS light before trying to crank her over? Let them suckers really get hot for 20sec or more

[RobertJory]

I'll try it tonight when I get home. Had to use my car because it wouldn't start. Thanks for the reply.

[Austin G]

Originally Posted by kx592

You fellas every do two or even three cycles of the WTS light before trying to crank her over? Let them suckers really get hot for 20sec or more

The glow plugs stay on for 2 minutes after the key comes on, the wait to start light is a dummy light so people wait a little bit. You don't need to "cycle" them, it just wears out the GPR.

[Strokeorcroak]

Originally Posted by AgentAustin

The glow plugs stay on for 2 minutes after the key comes on, the wait to start light is a dummy light so people wait a little bit. You don't need to "cycle" them, it just wears out the GPR.

Is this true in all years? I know if i leave the key on long enough the WTS shuts off for a bit then it will come back on for the 7 seconds or whatever

[kx592]

I no but its the simplest way to explain

[selancas]

any further info on this. I have an 06 350 doing all the above. Last year it was fine. I get LOTS of black smoke when I finally get it cranked over. Someone told me it was my gas gelling??????

[Austin G]

Diesel fuel dosn't start gelling until about -20, and if it gets that cold the stations will usually add additives.