I just bought a '97 F-350 133k miles. Previous owner advertised as rough idle when cold. Well, that was Memphis, this is Wisconsin. The truck starts OK, and then has extra vibration and "chuggs" a bit like a V8 gasser with a bad cylinder. I've let it warm-up for a minute or two, and then I head down the road. I take it easy, but can't run the RPM's too low (manual transmission) or it shudders and shakes. The previous owner said that when there is a hint of the water temp gauge starting to move, it will start to run fine. I have found that it doesn't run fine until the thermostat is fully open (i.e. temp gauge rises, t-stat opens and needle settles back on the line just after "C".) After the temp. stabilizes, it runs OK. This warm-up takes 3-5 miles on a country road. There is some white/blue smoke on start-up. Nothing excessive. Truck has good power after it is at normal water temp. I got 13 -15 mpg returning from Tenn. pulling my Grand Cherokee with a Tow Bar I have changed the oil/filter, fuel filter, drained the filter resevoir, and I'm working various treatments through the tanks. I would like to take this truck to Colorado next week, but I don't know if I can haul enough wiring harnesses, CPS, injector o-rings, gaskets, etc. to prepare for the inevitable. Unfortuantately, the local diesel expert is out of town.

Thanks,
Tim

 

(00 f250 auto), mine is doing the same thing I have to wait until the water temp gauge gets above the "C". I was told it might be the Glow plugs, the only difference I notice is I use to get a light "wait to start" now as soon as I turn on the truck no light and problem with truck happens. I going to take to dealership to run a test let you know what the problem is.

 

I would guess glow plugs as well. The reason is that if they aren't hot when the motor is cold, you get a misfire, which produces the white/blue smoke. But once the motor warms up, the glow plugs aren't needed to ignite the fuel anymore and you're running on all 8 then. It's been pretty warm here in CO, so you probably won't have to worry too much about it getting cold at night, unless you're in the high country.

Maybe try plugging the truck in for a couple hours before you start and see if your rough idle time is less.

J.D.

 

sounds like injector orings to me. get a gauge for your fuel pressure. put it in the port where the shrader is. you will see higher pressures cold with worn orings and is your fuel filter getting black?