New Injector Pump went "Dink"

[Plow Boy]

Hello,

I recently purchased a DB-2 4911 for my 1993 6.5l diesel truck. The old pump was warn and it would die occasionally and would not start warm. I also lost a lot of power and it was starting to smoke more and more. I installed the new pump and it fired up and ran well once the air was out of the system. I noticed a significant increase in power and almost no smoking at all. I was very pleased with the improvement. I ran the truck a little bit over the next couple days and then one morning (within a week and less than 10 miles on the new pump) I started it and after a minute revved it about 2000 rpms and right about at that point something under the hood made a sound like "dink" like hitting a vice with a small hammer. A very clean but solid sound. No rattle or ring just a crisp "dink" sound. Right away the engine started running rough and smoking. After warming up it ran ok. Less power than at first and a little smoke, but pretty smooth. The next cold start, it didn't want to start and I had to keep my foot on the gas to keep it running. If i removed my foot it would just chug and die. It runs very rough and smokey now till it is warmed up and then while it's drivable and still better than the old pump it still smokes and doesn't have the power it had when I first replaced the pump.

Any ideas on what happened?

My first thought was that the cold engine timing advance broke (and I have no idea how the injector pump works, so I don't even know how possible my thoughts are) which would account for the rough running, no very cold idle and the smoking. But this does not explain the warm engine smoke or loss of power.

Let me know what you think.

Thank you!

[mrwilecoyote]

Could be a bad IP. Also could have spun the keyway on the Cam to IP gear. When you were changing the IP how did you rotate the motor to get to the 3 bolts on the IP ? With a wrench or bump the key ?
Will it idle ? If so try pressing the advance piston on the bottom with a screwdriver and see if it makes any difference.
lso you did tighten the 3 bolts that hold the IP to the timing case cover right ?

[Plow Boy]

I rotated the engine with a wrench on the crank pulley bolts. the engine runs pretty well once warmed up. it's just when it's cold that it's very rough. I'll try the advance piston tomorrow and see what that does.

Thanks for your help

[mrwilecoyote]

Does it run like this ?

http://www.youtube.com/watch?v=pWRQp1fCHos&list=UUdb5JicXJ6rEUlfnbrRy3Iw&index=10

[Plow Boy]

Yeah, it ran just about like that. A lot rougher, as in the engine bouncing around, when cold and the smoothed out and smoked less once it warmed up. The plug for the cold advance somehow came undone from the hot water pipe and so plugging that in fixed the cold start problem.

I'm still getting smoke. It's a blueish white smoke that gets more blue at higher rpms.

The engine also shakes on while rpms are climbing and once I hold it steady it smooths out.

Sounds like late timing, but I don't know what would cause that to change suddenly.

The IP didn't turn. It's still set right where I put it when i installed it.

I tried pushing the advance piston as you recommended, and there was no noticeable change, but plugging that wire back in definitely improved it.

Thanks for you help on this.

[mrwilecoyote]

with the truck warmed up pushing that plunger in should make a noticable change. Either your timing is way off , the IP is defective or the IP gear spun on the keyway. BTW that vid I posted was a spun gear. Try moving the IP either way and see if you see any difference. You could have lost a nozzle too.