Hello to all, New to the forum.
I have a 17 columbia glider with 98 DDEC 3 engine
rebuilt by the shop that built the glider for me.

When I start the engine cold, it fires and skips rocking the truck back and forth for several seconds. Then it smooths out. After about 20 seconds i get a knock near the front of the engine like in the first cylinder. The truck shakes like it has a skip or the cylinder is firing to hard.
When the engine warms up, 15 or 20 minutes the engine idles almost perfectly smooth. The skip? and vibration comes back when i increase the idle to 1000rpm.
The shop that built the engine has given up. They kept on replacing injectors 3 individual injectors then 2 complete sets. No difference. I took to a different shop and had them check everything under the valve cover.
Other things i have checked are air in fuel, none check valve, good
camshaft good, rollers good, valve and injectors settings good. engine ground good. Batteries good, ground at batteries good.
Truck has good power and torque.

I am at a loss as is my local shop. Oh, using the cylinder cut out shows all cylinders are firing the same.

HELP I am sure i am not the only one who has had this happen.

 

"The shop that built the engine has given up", make sure you've been documenting EVERYTHING! This is a warranty issue and they need to make it right. If that means a another rebuild than so be it, don't let them wiggle away from it!