Another rough Idle

[FineOlBenz]

300 Turbo
Am I ready for new injector nozzles or could there be a problem with the injector pump??

Here are the symtoms and history:

1) Receipt in the glovebox shows that someone adjusted injector pump timing years ago at approx 15K miles to cure idling problem (Errr!!!!!).

2) Car had been setting for about 8 years. Fuel, filters, hoses and so on were changes out before I started it.

3) Valves have been adjusted. None found tight.

4) Diesel Purge two cans. No change. Should I try Bio?

5) When first fired up idle was good and smooth. After running a while (15, 20 minutes) a slight miss. Miss is only at idle and not obove 900 RPM. This rough idle stays day after day unless the car is left parked for a week or so. After a week it will start and idle smooth for a few minutes and back to the rough idle.

6) Each injector has been taken appart and cleaned out. Same symtoms.

7) Clear plastic lines at the injector pump show slight bubbling of air. I tryed purging numerous times, no change.

8) I've noted some of the roughness is coming from cylinder #2. Injector was replaces and then it seemed like cylinder #4. That injector was replaced and the miss is still there. Each time new heat shields were installed.

9) I say roughness at idle, not a dead miss. Cracking open injector #2 miss is greater, upon tightening slowly it will smooth out for about 2 seconds and proceed to miss slightly. This same symtom noted on cylinder #2 was there before I took out each injector and cleaned them out. What are the chances I put the same injector back in #2???

Am I ready to try new Bosio nozzels before another injector pump? Or is there a check valve in the pump that may need attention?


Help I'm drowning in used heat shields!!!!!!!!!!!