Volvo Maintenance Hints for 7xx/9xx - Bill Garland's Nuclear ...

Engine Tune and Performance; Symptoms: FAQ Home
Volvo Maintenance FAQ for 7xx/9xx/90
Cars Version 7.6
Abbreviations
Note: Symptoms may involve several potential failures, so diagnosis should start with
a general perusal of this entire section. Most of these notes apply to Bosch LH 2.2 and
LH2.4-equipped cars. Regina-equipped cars have some differences in components
and component failure patterns. Where known, these are noted in the relevent section.
Symptoms for B6304 engines used in the Volvo 960/90 series cars with Bosch
Motronic are covered in a separate 960 file. Diesel symptoms are covered in the diesel
file. Some notes relate to carburetted cars: they are identified as such.
Caution on Diagnostics and Shop Errors
General Symptoms and B2XX Series Engines:
Idle Problems:
Poor Idle, Idle Surge and Hunt: Cleaning Your Throttle Body
Poor idle, Smoke, Oil Leaks: Clogged Flame Trap
Fuel Intake Carbon Removal
Engine Dies After Starting, Won't Idle; Needs Intake Cleaning
Poor Idle: Injectors Need Cleaning
Poor Cold Idle: ECU E-Prom Needs Update
Idle Speed Control Problems
Start or Stall Problems:
No Start; Frequent Stall or Hesitation: Basic Diagnostics