How much can pump wear affect timing?

[wil892]

I have been sorting out my timing over the weekend with the dial gauge as the engine was running a little retarded. I've found the car runs well when the dial indicator shows 1.25mm, which is 0.25 over what it should be. If I set the pump to 1mm the engine is very retarded and isnt good at all. The engine has good compression. Does this sound like typical pump wear or is there something I'm missing?

The reading of 1.25mm is repeatable as I re checked it many times to check it. The engine doesnt sound diesely and pulls nicely especially when the turbo cuts in at 2000rpm.

The engine is an SB engine and uses 155bar injectors which are new bosch exchange units. My thinking was maybe the 80hp intercooled engines use a slightly different pump, thus requiring different timing. The bentley manual only lists engine timing info for the american engines. Anyone know what the official timing specs are for the SB engines?

Thanks
Will

[westcoaster]

If you could expand a little on the symptoms of retarded timing you were experiancing it would be appreciated.

I think I have the same thing (timing issue) but don't know enough to be sure.

Thanks,

[wil892]

I thought the pump was slightly retarded because the car would miss a bit from cold starts in low temperatures even with the cold start out. Also with hot starts without glow plugs it took 2-3 revs of the engine to fire, also was a bit smoky (whity blue) when accelerating when cold.
It now doesnt miss at all with the cold start out, and only slighty stumbly for about a second with it pushed in. No noticable smoke when accelerating cold, and the engine starts pretty much instantly when hot without glow plugs.
Also it doesnt sound really marbly like some of the ones on youtube, which I thought i would compare with. It sounds like a diesel but without the knock or ping i.e sounds perfect now.

I didnt move the pump much at all to advance it and I'm pretty sure the pump was already set over 1mm.

[westcoaster]

I need the cold start with temperatures as warm as 12*c

I smog the street out with a whitish blue when running down the road cold (first start in 24 hours) pulling the cold start out, it seems to clear it up a little.
Slow speed driving (stop and go traffic with more stop) starts smoking whitish blue until i get to the high rpm's.

I had it back at the shop today and he was telling me it was the turbo...

Hijack over, 

Thanks,
Jarl



 

[wolf_walker]

Injector pop pressure WILL effect the pumps timing.  If the inj's don't match the pump the stock setting's are
pretty out the window.  If it runs well, don't sweat it. 

[JT Turbo]

I seem to have had the same experience last week when putting the finishing touches on my 1.6TD rebuild.

Quite rough smokey cold starts (near 0*C) that I couldn't seem to cure until a friend mentioned this thread. With the pump set and reset and double checked at 1.00mm, I was running out of options. New glow plugs helped a lot - but the magic happened when early in the cold morning I loosened the IP, started the car and started to tap the pump to lean closer to the valve cover. The idle smoothed right out and the smoke vanished!! wow, right on!

When the IP was set at 1.00 mm, the cold start was rough and smokey, but ran clean and smooth with very little acceleration smoke at normal op temps.  Now with the pump advanced, it's kind of the opposite - very little smoke on start up, but noticeably more black smoke under even moderate acceleration with slight power loss, so I'm not sure what to do about that.