Any concern with these compression numbers?

[Poorman]

I've owned this 86 f350 dually 6.9 since about 1990, not sure of the miles because the daughter of the original owner said her dad had disconnected the odometer. I'm guessing 250-275000. It's been running great but smoking bad on cold startups but starts easily. I replaced the injectors/injector pump/return lines 18,000 miles ago (7.5 years ago). Over the last couple years sometimes when I get a mile from the house and start up a modest hill from a stop sign it starts belching smoke so bad I can't see the road behind me (embarrassing) but when I crest the hill and the revs pick up it cleans out and runs smoke free. So I thought maybe it was time for a rebuild so I did a compression test today (real fun) got these # 380/390/405/375/440/405/415/400 engine 2 hours post running, pugged in, so warm. About 8 revolutions but the last 3 or 4 only add another 10# or so. I checked the glow plugs (had to remove ) and 5 were dead, they have less than 5000 miles on them, didn't expect that because it starts easily. That could cause the smoky starts but I think something else is causing the horrible smoke a mile down the road on the first hill. I'm suspicious of my injectors, any ideas?

 

[Nero]

Numbers look alright, nothing crazy out of balance there. Who built your injectors and pump? Not all builders are equivalent anymore, could have some dud injectors.
Another point, did you set the timing for the pump, or just eyeball it?

 

[Poorman]

Nero, I bought the injectors and pump from Oregon fuel injection, they're Stanadyne. I've always ran their additive. The truck always got 10 mpg, after the replacements it went to a solid 12, it's only used to carry a 12 ft camper with a small trailer. My last trip this fall I noticed the mileage went back to near 10. It does sit for months sometimes, I wonder if that could effect the injectors? The heads were rebuilt 20 years ago , maybe 75000 miles ago. Lost the gasket after an overheat , issue with the radiator. Thanks!

 

[Poorman]

Forgot to answer the question on timing. I couldn't find anyone local that could time it, they all said they just go by ear, so I studied it a bit and that's what I did, I advanced it just enough to be a little noisy and it ran great, over time it has quieted down considerably.

 

[Diesilee]

Not that it would fix everything, but sounds like a dimes worth of advance
would be instructive.

 

[gnathv]

The way I’ve timed by ear was to jumper the cold advance and move timing until it clattered and would quiet down when I removed jumper. It gets it very close.

 

[Nero]

Isn't it as pumps and injectors wear in that the timing needs to be readjusted? Might be time.