Repair And Fix it

The most recent use of a 4.9-liter engine in Ford vehicle is in F-150 pickup trucks made from 1987 to 1996. This is a six cylinder gasoline engine, which requires the fuel injectors to deliver fuel to the engine under high pressure. The installation of a new fuel injector for a 4.9-liter Ford engine requires you to remove the entire fuel rail assembly. This procedure is generally the same for all Ford trucks with a 4.9-liter engine made since 1987.

Instructions

1

Disconnect the cable on the negative battery terminal with a socket wrench to reduce the possibility of a spark while replacing the fuel injectors. Open the filler cap on the fuel tank to relieve the pressure in the tank. Remove the cap for the fuel pressure relief valve on the fuel line and connect MFI Pressure Gauge T80L-9974-A to the valve. Open the pressure gauge to relieve the pressure in the fuel lines and replace the valve cap.

2

Disconnect the upper intake manifold assembly from the engine with a socket wrench. Remove the mounting bolts for the fuel rail and disconnect the fuel rail from the engine. Unplug the electrical connector for each fuel injector.

3

Rock the fuel injector back and forth as you pull up to remove the fuel injector from the fuel rail. Remove and discard any damaged O-rings from the fuel injector.

4

Coat the new O-rings with clean engine oil and mount them to the new fuel injector. Install the new fuel injector into the fuel rail by gently rocking it back and forth.

5

Attach the electrical connectors for the fuel injectors, and install the fuel rail with the socket wrench. Replace the upper intake manifold and connect the cable to the negative battery terminal.

The Cummings 3.9-liter turbo diesel 4BT engine is a straight-4 configuration engine used in automotive applications including small trucks, SUVs and commercial vans in addition to many off-road applications that include boating, construction equipment, farm machinery and other off-road uses. Owing mainly to its ability to generate high torque at lower rpm, this Cummins workhorse engine is a favorite replacement engine for any application calling for a small diesel engine or changeover from gasoline to diesel.

General Specifications

The 4BT measures 30.6 inches long, 24.6 inches wide and 37.7 inches high. It has net of 745 to 785 lbs. without fluids or accessories, depending on configuration. The "4BT" designation means it has four cylinders and belongs to the B series of Cummins engines. The "T" stands for "turbocharged." The 4BT is a four-cylinder version of the Cummins 6BT used in Dodge trucks as a replacement for eight-cylinder gasoline engines.

Mechanical Specifications

This 3.9-liter Cummins diesel engine is an eight-valve, in-line four-cylinder engine with a displacement of 3.9 liters, or 239 cubic inches. It has a bore of 4.02 inchesand a piston stroke of 4.72 inches. With the piston at top dead center, the engine has a compression ratio of 17.5 to 1. Engine air delivery occurs via a non-intercooled turbocharger. With the oil filter, the engine holds 10 quarts of oil.

Power

As originally manufactured, this four-cylinder diesel delivered 105 horsepower at 2,300 rpm and 265 foot-lbs. of torque at 1,600 rpm. As of 2010, recent configurations deliver 130 horsepower and 335 foot-lbs. of torque. You can easily tweak the engine for more power by adjusting or changing the turbocharger, or by using different injector nozzles.