What is calculated fuel rate?
Fuel rate – average amount of fuel delivered to each cylinder measured in mm3/sec. It is an average. To calculate this value, the fuel rate for each cylinder is added together and then divided by 8 to obtain the fuel rate.
What is a CP3 on a Duramax?
The Fleece Performance CP3K is a modified Duramax LBZ CP3 designed to eliminate the factory fuel flow restriction that begins at 3,000 RPM. If you have a stock CP3 pump you are losing fuel flow and rail pressure after 3000 RPM, which correlates to lost horsepower when you need it most.
What causes low fuel rail Duramax?
What is happening to cause this? The direct answer in most cases: Injectors. Simply put, the backflow or return rate is excessive so the pump does not keep up and rail pressure drops. Our testing of suspect injectors has shown backflow rates of 2x the factory spec or more.
What should my injector balance rates be?
When viewing the rates, a cylinder with (+) means that its injector is using more fuel than the average fuel rate and a (-) translates to less fuel. GM states that balance rates should be no more than plus or minus 4 (+4/-4) in park at operating temperature.
What should the fuel rate be on a Duramax truck?
A Duramax truck with stock injectors and tuning, at operating temperature, should idle with a calculated fuel rate (CFR) of 7-9 mm³ – and that is the baseline, i.e. balancing point, from which each of the individual cylinders gets its rate from.
What’s the normal range for a Duramax injector?
The normal ranges for automatic transmissions is +/- 4 mm3 in park or neutral, and it can go as high as +/- 6 mm3 in gear. Starting on 2006 all Duramax injectors use an injection quantity adjustment number on top. This is established by Bosch during testing.
What is the low fuel pressure code for Duramax?
Duramax LBZ and LMM P0087 Low Fuel Pressure code
Where are the injector return lines on a LB7 engine?
2. Injector return lines are under the valve cover on LB7 engines. Pressurize the return circuit with the valve covers off and look for bubbles or vacuum test the return circuit off of each head, the return should hold 15 inches Hg of vacuum. Oregon Fuel Injection