Improving Mileage and Performance on Your Older CIS Injected Benz Gas Engine

Most owners forget about the fuel injectors - Cap, rotor, wires and plugs may not be enough

1976 to 1993 Gas engine Bosch CIS fuel injectors are very reliable and require little maintenance UNTIL the engine ages. Let us face it, most of these engines are 25 to 35 years old. The fact that the injectors still work with regularity is almost a miracle. BUT, you may be losing gas mileage and performance without even knowing it. The injectors most likely have become dirty and gummed up and fuel tank injection cleaner is just not going to "cut it."

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Problem & Solution

Common among these chassis:


The only real solution is to remove the fuel injectors from the engine and clean and bench test them. Having this done at a shop can be quite expensive. Sometimes it just may be as cheap to buy new injectors. But we have found that 70 to 80 percent of the injectors can be saved if they can just be adequately pressure cleaned and balance tested. 

Kent's custom CIS fuel injector tester and cleaner can do just that. It is not hard to do this yourself. Kit comes with all the extras you need to mount this on a bench and start testing (actual injector cleaner is not included). 

Be sure to watch Kent's on demand 32 minute video manual on the process of removing, testing, cleaning, and retesting CIS injectors. PLEASE NOTE: This video is added free of charge to your order when you purchase his CIS pressure tester. Please see related products to order. 

To purchase the tester and related parts see related products here. If you already own the diesel injector tester you can just purchase our conversion kit.