99 F350 surges at 1500rpm and rough idle

[oteps]

I have a 99 f350, all stock. 325,000 miles. At idle the truck shakes, when driving at 1500 rpms in drive or od. Every couple hundred miles it starts to smoke for a couple minuites, the smoke is white and smells like diesel. But if you shut off the truck and start it up 15 mins later it stops smoking. The ses light is on because of a map sensor. I replaces the map sensor and the light came back on right away.
I have recently (within a couple hundred miles) replaced the injector o rings, glow plugs, map sensor and the cps.
Any ideas?

[oteps]

any ideas?

[bjg8599]

sounds like an injector is going bad or two. why did you have o rings replaced?

[oteps]

It was starting hard when it was 35 degrees out or below, so i put new glow plugs and injector o rings in it. 2 of the old o rings were all torn up. The surging and idleing problem started about 700 miles after i replaced the o rings and glow plugs.

[bjg8599]

Originally Posted by oteps

It was starting hard when it was 35 degrees out or below, so i put new glow plugs and injector o rings in it. 2 of the old o rings were all torn up. The surging and idleing problem started about 700 miles after i replaced the o rings and glow plugs.

yea this sounds like an injector going out but it could be a loose harness on the injectors. the torn up o-ring are normal if they have never been touched before. these injectors usually last around 350,000 miles, some go a million or more. are you sure that it is surging and not lopping? surging would be excess fuel which is a totally different problem.

[oteps]

At 1400 to 1600 rpm the truck shakes, kinda like when brake rotors are warped and you hit the brakes hard. Any rpm outside that range it runs great. The tach stays steady when the truck shakes. I am thinking its an engine problem but could the tranny be causing this? I just had the tranny rebuilt about 3000 miles ago.

[oteps]

I put a can of sea foam in the fuel. I am gonna see if that does anything. I might pull the valve covers off and unplug one injector at a time to see if that makes a difference.

[oteps]

sea foam didnt do anything yet. I checked the manifolds with a temp gun. I have 2 clyinders running 100 degerrs lower than the other ones and one running about 20 lower. i guess its time for injectors.