1999 Volvo Penta "WT" Models Workshop Manual, Page 36Get this manual
Engine Troubleshooting Guides EFI Engines Only: Refer to EFI Diagnostic Service ManualThese guides were written to help you trace the symptoms ofthe trouble to the source, without having to read through and prove every possibilityMuch of the information here will be familiar to well informed mechanicsAlso, many factors will seem insignificant but when you think of it, usually the toughest problem to troubleshoot is caused by the smallest errorThe greatest aid to solving service problem is informationStart gathering information from the boat operator and write it on his job card or work ticketFind out pertinent facts, such as: When did this trouble start?
How was the boat loaded?
Did the trouble occur suddenly, or start gradually? Analyze this information and try to match it to similar situations you have experienced in the pastKeep in mind the fundamental rules: 1COMPRESSIONMixture inducted into cylinder and compressed2SPARKProper intensity at the proper time3FUELProper mixture of air and fuelThese are very old rules, but necessary for the engine to runUse these charts and the service information they refer toDo not try to remember tolerances, settings, measurements, etc as they are written in the service manualLeave your mind free to analyze the problemFollowing is list of the troubleshooting guides which may be found on the pages indicated