How hard is it to do a CP3 conversion?

The CP4. 2 to CP3 conversion is relatively straightforward (as much as it can be when accessing an injection pump sitting at the very front of a 6.6L Duramax LML engine’s valley).

What is CP3K?

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.

How do you avoid CP4 failure?

The problem with the CP4 pump is so well known that several companies sell expensive kits that cost up to $3,600 (before labor costs) to try to prevent the problem. Popular fixes involve boosting the fuel pressure with an additional pump, or replacing the CP4 with the more reliable, but less fuel efficient, CP3 pump.

What percentage of CP4 pumps fail?

The Bosch CP4 fuel pump has an unusually high failure rate in the U.S., upwards of 7%, when compared to 1% failure rate in Europe.

Is there an upgraded CP4 pump?

Description. GM OEM Newly Updated Stock Replacement CP4 Pump. This is the New Updated CP4 from Bosch that Took Care of the Failures the Early Version Pumps.

Why is the CP3 better than the CP4?

Should one decide to “tune” the engine, a CP3 can support more horsepower than the CP4 because of the higher fuel volume it’s able to feed the injectors. The CP4. 2 is said to support fuel for only about 525 horsepower, while a CP3 can support up to 800 horsepower.

How long does a Duramax fuel pump last?

On average, a vehicle’s water pump should last well over 100,000 miles. Unfortunately, those who drive Duramax 6.6-liter engines usually have to replace theirs by 80,000 miles. In some cases, the pump will last to 100,000 miles, but it usually fails much earlier than an average water pump does.