1982 300SD with 475K km on the clock.

Two symptoms:

1. regular miss on startup for about 3 minutes until warmed up a bit. Bad enough that it simply won't idle for the first few blocks even though I've set the idle up to 1000 RPM. Slight nailing, but not too bad. As soon as warm enough to move the temp gauge, misfire and nailing is gone.

2. Power seems generally low, cold or warm. This is not very precise I have to admit. I mean compared to previous 300SD I've owned and measured by the seat-of-the-pants-O-meter. I don't have any 0-100 times or anything. Not easy to get those around here in the city.

Diagnostics:

Compression is 1-2-3-4-5= 400+, 400+, 350, 400, 350
Valve timing is spot on and chain is new
Valve clearance done 3 times in the last year. Spot on and stable
Pump timing spot on at 25 DBTDC
Some blue/gray smoke on startup.
LOTS of grey smoke when warm and full throttle. No problem with fuel delivery!
Oil consumption very good (< litre per 4000km)
Filters (air and fuel) good.

What next ? (comments/opinions welcome):

Bad valve seals leaking oil into cylinders overnight. Lowered fuel volatility, leading to miss until burnt out. That would explain the miss on startup. Nailing from unburnt fuel on second compression?


OR

Turbo problem, with low boost pressure from . . . something amiss, leading to reduced power



Is there some way the two symptoms could be related. They have been present for some time and resisted all attempts so far to rectify. Could a bad turbo give a miss at startup?? Could poor valve seals lead to a loss of power? Something else?

If you are having gray smoke before 2000 rpms it is unlikely to be a turbo boost issue.

Checke the Glow Plugs; but that would not explain smoke after the Engine is warm.

Gray smoke; Fuel Injection Pump Timing or worn Injectors.

Valve Stem Seals are cheap but there is some careful labor involved.

This site seems to try to cover too many things but the stuff is there:
Diesel engine exhaust and remedy the cause of abnormal « Nozzle « Diesel Engine System

One of the sites had an interesting though to do the Injector Cut Out Test to see if it is a bad Injector. That might explain the Miss.
If the gray smoke is not steady and puffing out that could be an indication of a bad Injector.

Another site. It dose not have a colum for Gray Smoke but the stuff for Black Smoke due to incomplete combustion can apply. It also has the EGR on the list.
http://www.dieselsmoke.com.au/

__________________
84 300D, 82 Volvo 244Gl Diesel

Ahh, a few more items should have been in the list:

Glowplugs all pulled and bench tested good on 12V. Bores reamed on install.

Injectors all pulled and sent to a pump shop for spray test; one or two required new shims and all got cleaned. Compression test was done while injectors out.

As I said, I've been chasing at this for a while. Other problems have been fixed but this has been. . . stubborn.

I should say, in my opinion, the smoke is normal after warmed up, all the way from idle to just before the call for warp speed -- at which point I am overfueling for sure. In normal daily driving this never happens. It just shows that the low power is not (obviously) coming from a lack of fuel compared to air.

Wow. That's a mindbender. Typed on a cellphone perhaps??

. . . strangely, information correct coded there under, agree I . . . thanks.

more likely, it's a translation by an online translation matrix...
odd indeed... I had no idea my valves had a catheter...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!