Home Bronco TSB Summaries Recent Updates Gallery Submit A Link Unique Visitors: 376106	FORD BRONCO -> ENGINE & COOLING; swaps, specs, snorkels, vac. diagrams... -> Carbon Deposits WELCOME to MIESK5's BIG BRONCO LINKS - We now have over 29,162 LINKs! This is a Ford Bronco, Truck & Van Technical & Parts LINKS site developed by the MIESK5 Family & is not affiliated with the Ford Motor Co. in any manner. Although we initially developed this site for 78-96 Big Broncos, information in many Links also applies to F, E Series & Cars Select A Link: Carbon Deposits; As a vehicle approaches higher mileage, you can generally expect intake valve deposits (IVDs) and injector deposits. Their onset can vary widely, depending on driving conditions. Engine operating temperature, intake manifold gas speed (rpm) and hot soak cycles are some of the critical operating parameters affecting these deposits. To lubricate an intake valve, tiny amounts of oil have to run down the valve stem. Over time, this oil is deposited and heated on the intake side of the valve, forming a carbon cone. This has multiple effects on the intake event, The carbon changes the aerodynamics of the intake event-namely causing higher gas speed and a change in the direction of intake and swirl, which affects the combustion process. The IVDs also act like a sponge, creating a delay in fuel control. This delay not only creates a temporary enleanment on acceleration but also causes a temporary enrichment on deceleration. When the throttle is closed, the intake manifold vacuum goes high, pulling the fuel out of the carbon sponge. This affects fuel control, potentially affecting catalytic converter diagnostics under OBD II. Source: by Mark W, in Motor, Dec 2002 Deposit Control Standards; The standards developed by the four automobile manufacturers (BMW, General Motors, Honda, and Toyota) for TOP TIER Detergent Gasoline are described below. This technical document describes the deposit control performance of unleaded gasoline at the retail level that minimizes deposits on fuel injectors, intake valves, and combustion chambers. These standards comprise the requirements for TOP TIER Detergent Gasoline. Source: by toptiergas.com