7.3 horrible running and no power until full running temp

[dj25cent]

i have a 2000 f550 6spd, i bought it a couple days from some ppl and apparently they had it warmed up when i drove it cuz it purrs like a kitten once warmed up, but cold i have to cycle the glow plugs a couple times before it will start and when i mean cold, texas cold 30degrees ... but any way once running it runs really really and if you drive before it up to full running temp, there is no power and it runs horrible and rough, if you really get on a check engine light comes on i checked it with my obdII and nothing so i let it warm it, and it runs great again, any ideas would be great
thanks
tim

[20stroker02]

how many miles are on it?

[dj25cent]

o im sorry it has a 150k i have no history at all so im changing oil fuel and air filters tomorrow

[20stroker02]

I would also change the fuel filter, dependant on the last time any of that was done it could be the cause of your problems, after that I would check the EBPV(exhaust back pressure valve) it could possibly be gummed up

[Deeslfxr]

Does it have to reach operating temp. or just warm up enough to clear up. When you say it's running rough is it possibly missing on 2 or more cylinders? I am wondering if you don't have a UVC harness coming loose or bad G/Ps.

[dj25cent]

alright thanks yall, being that i just bought it , it had not been to my service center yet for the oil fuel and air filters changed, o prolly should have done that first, before posting a thread, anyways i just got everything replaced, and it purrs like a kitten all the time and starts right up even when cold, the fuel filter was jet black and was full of sludge, its a completely different engine now, no running rough and 40% more power
thanks alot

[Deeslfxr]

YAY!!! Good news! Glad you're up and running!

[boweb616]

Hello, looking for some answers please. Not hard start just longer than usual to fire up and when it finally starts it runs right for about 5-10 seconds thens runs so rough like hitting on 3-4 cylinders, motor shakes the whole truck. 20000 f 350 4x4 bought new has 90,000 miles on it with 6 injectors replaced at 74000 miles and other 2 had new o rings. fresh oil, fuel and filter. Checked wires under drivers side fender well all look good. Been down since Dec. fuel pressure at 75-80 at drain hose. what do you think???? bob