Fuel injection
R107 Running Rich: Black Smoke and Fuel Smell
Signs an R107 is running rich, and the usual causes: warm-up regulator, leaking cold start valve, injector leaks, mixture adjustment and the oxygen sensor.
Guide hub
Fuel injection guides
K-Jetronic and KE-Jetronic explained, hot and cold starts, idle problems and fuel pumps.
All guides
Fuel injection
R107 Hesitation on Acceleration
Why an R107 hesitates or stumbles on acceleration: vacuum leaks, warm-up regulator, airflow sensor plate, ignition and KE-Jetronic EHA, with a diagnosis order.
Fuel injection
R107 Stalls When Warm or at Idle
Why an R107 stalls when warm or at idle: vacuum leaks, idle control valve, fuel accumulator and hot-start problems, ignition faults and a step-by-step check.
Fuel injection
D-Jetronic on the Early 350SL/450SL: What Owners Need to Know
Which early 350SL and 450SL models use Bosch D-Jetronic, how it differs from K-Jetronic, what fails, and whether to keep or convert it.
Fuel injection
R107 Air Flow Sensor Plate: Centering and Rest Height
How the R107 air-flow sensor plate works, how to check it is centered and at the right rest height, and the mistakes to avoid.
Fuel injection
R107 Oxygen Sensor: Location, Test and Replacement
Which R107s have an oxygen sensor, where it is, how to test it, which to buy, and how to replace it.
Fuel injection
R107 Idle Control Valve: Symptoms, Test and Cleaning
Which R107s use an idle control valve, how it fails, how to test and clean it, and what a replacement costs.
Fuel injection
R107 Fuel Tank: Capacity, Rust, Removal and Cleaning
R107 fuel tank capacity, where it sits, how to spot tank rust, and when to clean, coat or replace it.
Fuel injection
R107 Fuel Filter: Location and Replacement
Where the R107 fuel filter is, how often to change it, which one to buy, and how to replace it without leaks.
Fuel injection
R107 Fuel Injectors: Testing, Cleaning and Replacing the Seals
How to tell when an R107's CIS injectors are the problem, how to test spray pattern and leak-down, and how to reseal them properly.