Injection Nozzles: Notes
If exhaust gives off intermittent clouds of black smoke, this usually means one or more nozzles are operating unevenly. If exhaust offers a rumbling noise, it usually indicates one cylinder is partly or completely out of action. To determine problem, check injection nozzles as follows:
- At idle, loosen each injection pipe cap nut (in turn) one-half turn. If sound of engine does not change, part of problem is a defective nozzle or inadequate sealing between pipe union and nozzle holder.
- Raise engine RPM above idle speed and repeat test procedure. If engine still does not run erratically with nut loosened, repair or replace that particular nozzle. If engine runs erratically when nut is loosened, nozzle is operating properly. Tighten one-half turn and check next nozzle.