I switched out cold start sol, shut-off sol, injectors and did compression check (one 330 rest 450) but still smoking bad light gray smoke below 900 rpm. Rev to 11-1200 and smoke is passable. Pushing in plunger on IP side causes no change in rough idle.
Should I try advancing (or retarding) pump before replacing? Mileage on pump is unknown - injectors said 2001 rebuild.
any suggestions will receive my best blessing for your time.
Thanks!

 

Sounds to me like you have a cylinder that is not firing at idle, as indicated per the compression test. Strong IP and fresh injectors might help it, but bottom line is that cylinder is still weak. May be worth it to pull that head to see if it is a burn valve, or at least something simple. While its off you should also be able to tell if its rings, cracked piston.. or whetever it is if its not in the head. Could just be a leaky HG.

 

Thanks - I was afraid of that. I thought by searching previous posts that anything above 300 lbs was ok, but I guess I'll have to bite the bullet for a teardown.
monte

 

Are you getting any coolant/oil mixing? Did it just start doing this after you made the changes you listed? Which cylinder is at 330PSI?

 

does the smoke go away after any amount of time?

 

thanks fellows,
the smoke is there before and after injectors, cold start, new return lines, radiator w/ correct coolent (not losing any) both cold or warm.
the cylinder w'330 lbs is #8 ? (closest to radiator on drivers side).
For a quick look-see, is it possible to buy a single head gasket, and manifold gasket rather than a complete set?
Thanks again!

 

That's your number 2 cylinder. It is not very common to have issue with that cylinder. I'm not sure about buying the gaskets separately but you will have to replace both if you pull the heads. The intake manifold gasket/valley pan must be replaced once you remove the intake manifold. I would do both head gaskets while you have the engine out of the truck. If you plan on installing a turbo in the future, this is the optimal time to install ARP head studs. You will never have an easier time doing all of these jobs than with the engine out of the truck. Take advantage of that and save yourself some headaches down the road. The head studs are great of you want to run higher than 10-15 PSI boost but also are good insurance against head gasket issues in the future. It's up to you, though.

 

Sounds like not all the fuel is being burnt on the one cylinder, due to low compression temp.

 

OP, how old is you IP and injectors? have you had the injectors pop tested yet.

 

Thanks for everone taking time to help me here. I was just about ordering a replacement IP thinking that may be the problem. I think the suggestion that the low compression on #2 cylinder (how can the right forward cylinder on passenger side be #1 and not count back like other engine cylinder numbering?) anyway, I believe that 330 lbs is not enough compression to burn fuel at idle and will take this motor apart to bring all cylinders up to 450.
youall have a good day dieseling!
Montemontana

 

The numbering alternates side to side so that the passenger side is all odd numbers and the driver's side is all even numbers. There are numbers on the intake manifold but they may be covered in dirt and grease. Good luck, I hope you get it worked out. If it weren't for the compression test, I would have advised you to look into a bad injector but without good compression, you won't get good ignition. Maybe you will get lucky and it is just a head gasket.

 

do a cylinder leak down test to find out were you are leaking compression from in the low cylinder.