Cold Start Smoking Briefly while backing up only

[Black dawg]

Can have a fast idle without the advance working. With cold idling engine, pull cold advance wire from pump, should be a noticeable change in sound.

 

[hidyusa]

1986 F-250 XLT 6.9L Navistar 355,000 miles (approx) dual fuel filters

My parking area over the last 20 years has been on a 10% down grade driveway. I park front end down because if I park rear facing house, it is harder to start, but easy to start when pointing downhill in my driveway.. My assumption has always been that an air bubble is forming in the fuel lines of the fuel filters. So I have always parked front facing downhill.

Recently I have noticed that occasionally once warmed up with block heater, as I back out uphill, it appears that white smoke blows out, until I reach a level plane. Then never while driving. In fact once I start it white smoke is not emitted, only the short 18' distance while backing up the drive. And not every time.

Any ideas? Or could there be water in the fuel filters?

White smoke is raw fuel. Backing uphill will lower RPM's and my guess is that an injector or pump is not atomizing fuel like it should. Hard starting facing a different way is air intrusion probably in the return side of your fuel system, through lines, filter housing or the pump seals itself.

 

[Old-Red]

Thanks hidyusa, I'll get to that when things let up, but lately no problems with better weather.......??