Timing issue on a DB2 IP - white smoke or too much clatter.

[WarWagon]

I just put a rebuilt IP on my 1993. In order to get the white smoke to clear up at idle the throttle bracket is hitting the coolant crossover. At freeway speed and heavy throttle the diesel clatter will not go away indicating too much advance. (There is about a 1/4" advance by the timing lines.)

Best I can tell the cold advance is working and the light load retard is working. (Tested both. Clatter changes with throttle on the retard ramp.) When I reduce timing I get the white smoke, constant, returning at idle after running around the block to warm it up. However the freeway high load clatter is 'normal' vs. excessive.

The last pump had a shot head and rotor, but, did not smoke white. Timing chain is fairly new. Even if I skipped a tooth changing the pump the timing spread from idle to full speed is too narrow.

Am I missing anything outside of a bad rebuild? Any changes I can make before ripping the pump out... again... :mad2:

 

[ak diesel driver]

who did the rebuild?

 

[6.2 turbo]

Sounds like you need to play with the advance cam. Too much light load clatter has always been a problem area for me. Leaking injectors,are a suspect also.

 

[3500GMC]

Some trash in the lines during swap.. Fouled up a few squirts?

 

[WarWagon]

Shop said to turn up the timing till the white smoke went away at idle. Then monitor a glow plug for erosion every 1K miles as this would be timing set to advanced.

The timing fades away on high mile pumps so it was suggested that the rebuilt pump would sound different from full advance.

Course they recommended a timing meter being used... Not like I have one and the timing tang is bent on the engine anyway.

I wonder if the gears may have jumped a tooth during the IP swap to move the pump this much.

 

[3500GMC]

I've tried getting the gears to jump a tooth with an experiment, water pump plate off, to no avail.. The IP gear fits just snug enough in there to keep this from happening.. At least in the timing cover I was dorking with. :skep:

GM cast the timing cover pretty tight around the components.

 

[Will L.]

X2 on no jumping tooth, a fleet I wrenched at had a 300,000 + mile truck with original pump and timing gear and I tried to jump that super stretched chain to make up for the timing and it was a no go.
Timing does go on pump but not usually as much as from the timing chain stretch.

You have enough miles on these engines to feel what is right by the sounds of it to me. If the shop insists I'd say go with there call, but be a squeaky wheel about it and if the problem doesn't clear soon, then have them look at it. Even before that I'd be letting them charge book time for them to time it so that argument is off the books.

If you do check the glows at 1k, go ahead and check compression while your at it just to rule it out.

I have the Mac tools timing pickup head unit (not the glow reader) and I don't even bother with it usually. I played with it afterwards and always got better power and mpg by tweaking it. I drive it a day, see how it feels, top off fuel record mpg then move it 1 mm and do it the next day till I found the sweet spot. Good luck to ya...

 

[WarWagon]

Finally got it set last night by letting the cold start kick off and adjusting for no white smoke. Clatter at freeway speed is still there but not as loud.

I have to agree a fresh pump is harder to time as it isn't as sloppy.

I am not going to solve the mystery as to why it is so far advanced by the lines.

Finally got a decent pump and decent starts again.