Exhaust Brakes

How does an exhaust brake work?

Most exhaust brakes have a toggle switch mounted on the dash to turn on the exhaust brake controls. The exhaust brake also has a throttle position switch. When the toggle switch is on and the throttle is released, the brake is activated (butterfly closed) to provide exhaust retardation. When the butterfly is closed, it turns the engine into an “air compressor” by forcing air out of the engine under pressure (on the exhaust stroke). This causes the engine to provide retarding power through its connection to the drive wheels. The brake releases as soon as either the throttle is applied or the switch is flipped off.

How do exhaust brakes on automatic transmissions work?

The torque converter clutch must be locked up during deceleration to fully utilize the holdback of an exhaust brake. If the torque converter is not locked up, then the drive wheels will “drive” the torque converter, not the engine. The exhaust brake has more “hold back” at higher RPM because of higher back pressure. The B/D AutoLoc device controls the torque convertor clutch for lockup on deceleration.

How do exhaust brakes on gasoline engines work?

We don’t recommend using an exhaust brake on a gasoline engine because they create too much heat. Unlike a diesel engine, which delivers no fuel on deceleration, a gasoline engine continues to deliver fuel on deceleration.

Diesel Fuel Injection

How much does a repair cost?

Repair costs depend on the make and model of your fuel injection pump or injectors. Oregon Fuel Injection has many different exchange units in stock at a set price so you can find out ahead of time how much it will cost.

Can I turn up the fuel to get more horsepower?

Depending on the application, there are often many ways to increase power without violating emissions laws. Just turning up the fuel, without air flow improvements or other changes, will create higher exhaust gas temperature (EGT) and is usually not emissions legal.

Can you fix only what is wrong?

Yes. For example, you may have a leak around the throttle shaft that could be repaired without having to completely rebuild the pump. However some “partial” failures are signs of what is going to happen to the rest of the pump in a short time. It would not make sense to do a partial repair if other parts in the pump are badly worn, or may fail shortly because two partial repairs are often more expensive than a complete overhaul.

How long will it take to fix my pump or injectors?

Repair times vary depending on the type of pump or injectors. With an appointment set up ahead of time, our service goal is same day turnaround. Some units take longer, such as 24 hours. Contact OFI with the part numbers of your unit and we would be happy to let you know what kind of turnaround we can provide. We stock many exchange pumps and injectors so that the only down time you should have is the time it takes to replace the old unit with the rebuilt one.

Should I use a fuel conditioner?

Yes, we recommend the Stanadyne Performance Formula. This fuel conditioner is beneficial for many engine and fuel systems applications as it provides cleaners and lubrication for the fuel system.

Performance Products

Does the installation of performance parts improve fuel economy?

Sometimes! Gasoline engine applications most often will see a MPG fuel economy increase. Diesel engine applications normally maintain the same MPG, yet will have more power.

Is the Installation of performance products emissions legal?

All of the performance products Oregon Fuel Injection installs are emissions legal. There are many products on the market that are not; if it is not legal we will not install it.

Some of the performance products we sell on our website are not emissions legal. If you are interested in a particular product, we would be happy to let you know if it is emissions legal before you purchase it.

Can I just add a chip to get more power?

Yes, but performance chips basically just add more fuel and change timing. Most engines need improved airflow and both intake and exhaust improvements to work with the additional fuel. Otherwise, you will exceed maximum recommended exhaust gas temperature (EGT) and shorten the life of your engine.


How do turbochargers work?

Oregon Fuel Injection diesel FAQ on turbos

A turbocharger is an exhaust-driven air compressor. It becomes an air compressor by utilizing expanded exhaust gases from the engine. The exhaust gas pressure and the heat energy extracted from the gas causes the turbine wheel to rotate, thus driving the compressor wheel through a common shaft. Exhaust temperature and pressure drop as they pass through the turbine housing and into the atmosphere. The rotating compressor wheel draws air in and the blades accelerate and expel the air into the compressor housing. Once into the compressor housing, the air is compressed and flows toward the intake manifold, pressurizing the intake in a measurable form we call boost pressure.

Turbo FAQ, Oregon Fiel Injection

What is a wastegated turbocharger and how does it work?

A turbocharger is designed to provide peak boost for the engine under maximum power at high RPM. Because of this, a turbo is less efficient at providing boost at lower RPMs and in the torque range. In order to improve boost at the lower RPMs, smaller wastegated turbine housing is put on the turbo to allow the boost to build sooner in the RPM range. To prevent over boosting, a wastegate actuator opens as the boost reaches maximum pressure for that engine and “dumps” the exhaust gas before it spins the turbine wheel any faster.

My turbocharger is leaking oil. Can you just put seals in it?

Yes. However, seals in a turbocharger are usually a piston ring style. These piston rings rely on close tolerances; for instance, when tolerances are excessive due to worn ring grooves, bearings, thrust washers, etc. Just replacing the seals will not fix a leak. Oregon Fuel Injection stocks many exchange units—rebuilt and new—on the shelf for a reduced downtime for you.

How do I troubleshoot my turbocharger?

Before you replace the turbocharger on your engine because of low power, check the following items with the engine shut off:

  1. Wheel and shaft are loose side to side: This is normal, because with oil pressure to the turbocharger, the shaft (and bearings) floats on a film of oil. If the compressor wheel or turbine wheel is in contact with the housing, then the turbocharger needs to be replaced.
  2. The shaft and wheel assembly spin freely: If it is stiff to turn, replace the turbocharger.
  3. Check the air filter: If plugged, replace it because the engine will not get enough air.
  4. Exhaust manifold (or “feed” piping to the turbocharger): If exhaust gases are leaking, then the turbocharger will not spin “up” to full speed, causing low boost.

Why do premature turbochargers fail?

  1. Lack of lubricant can cause high-speed bearings to fail. Bearing failures can lead to instability in the way the wheel and shaft assembly rotates damaging seals and allowing the wheels to rub against the housing. If continued, this condition can lead to turbocharger failure.
  2. Foreign objects can damage the high-speed turbine and compressor wheel blades, causing wheel imbalance and unstable rotation. This puts an additional load on bearings that leads to bearing failure and eventually turbo failure.
  3. Contaminated lubricants can score shaft journals and bearings, block oil passages and wear out seals, resulting in heavy leakage. Continued operations under these conditions can result in bearing failure.

Turbocharger failure can be prevented with careful installation, proper operation and a sound preventative maintenance program.


What is OFI’s warranty?

  • One year on rebuilt pumps, injectors and turbochargers.
  • One year on most performance product installations.
  • 90 days on most electrical and electronic equipment.
  • Note: Warranties on partial repairs only covers the parts that were replaced or the sub-components that were rebuilt.

Does the installation of performance parts void factory warranties?

No. The performance products we sell and install do not void the original equipment (OE) warranty and after-market parts are not covered by your OE warranty.