Valve adjustment issue?

[BigPapa]

Our friend Solar1 sent this to me in a PM. I THINK he meant to post it, so I’ll post it here. Maybe he’ll find it.

“well folks, I finally got my truck back on the road this summer after all the body/frame work, and painting.

I did do a valve adjustment. I found that Cummins must have broke the timing locate pin because it didnt work. I had to visually line up the valve position.

Im don't think i did a good job adjusting the valves. Truck ran fine this summer, but now with the colder weather, its very hard to start. Miliage has dropped to 10-12 mpg from the 18-20 i was getting prior to valve adjustment. Maybe injectors finally acting up, but I dont trust myself anymore. It was my first time doing the valve adjustment on this engine. I have never had a problem adjusting valves on other stuff, so i felt confident when performing the adjustments.

any idea on where to start to analyze me cold starting problem?”

well folks, I finally got my truck back on the road this summer after all the body/frame work, and painting.

I did do a valve adjustment. I found that Cummins must have broke the timing locate pin because it didnt work. I had to visually line up the valve position.

Im don't think i did a good job adjusting the valves. Truck ran fine this summer, but now with the colder weather, its very hard to start. Miliage has dropped to 10-12 mpg from the 18-20 i was getting prior to valve adjustment. Maybe injectors finally acting up, but I dont trust myself anymore. It was my first time doing the valve adjustment on this engine. I have never had a problem adjusting valves on other stuff, so i felt confident when performing the adjustments.

any idea on where to start to analyze me cold starting problem?

 

[BigPapa]

Sounds like something’s off on your valve adjustment.

As to your timing pin, sometimes there can be a buildup in the bore that doesn’t want to let the pin go past. You’ll have to pull the pin to clean it out. You can pull the timing pin completely out to see if the nub is broken off. It’s just held in by a retaining “washer”, not a snap ring. I used a pair of long needle nose pliers. Get the head of the pin as far up in the bee of the jaws and lever it out against the tips. The resistance of the o-ring will hold it in, so don’t worry about the retainer.

You can use a bore scope to see the hole in the cam gear or, get a helper (my daughter helped me) to stick a finger in the hole to feel for it as you turn the engine over. Once you’re close, stick the pin back in and gently push it as you slowly turn the engine and it will fall in.

 

[GAmes]

I have that hard to reach pin RTVd to it's housing and have only used it once, back in about 1998. The FSM has instructions to find TDC to accurately place the adjustable timing pin housing to the back of the gear housing. A lot of us call that procedure the "drop valve method" to find TDC. I recommend you use that method rather than doing the gyations it takes to push and pull the pin.