Denso HP4 294050-0123 High-Pressure Fuel Pump – Performance & Application Guide
The Denso HP4 294050-0123 common rail high-pressure pump is designed for medium-duty diesel engines that require higher fuel delivery capacity and stable fuel pressure.
Compared with the Denso HP3 pump, HP4 features a three-plunger design that provides approximately 1.5 times higher fuel delivery capacity, while maintaining common rail pressure up to 1,800 bar.
Key features:
✅ Denso HP4 second-generation common rail technology ✅ Three-plunger structure for higher fuel flow ✅ Designed for medium-duty diesel applications ✅ Compatible with Isuzu 4HK1 and 6HK1 engines ✅ Suitable for commercial trucks and heavy-load operation
Common issues include SCV failure, plunger and barrel wear, fuel contamination, and low rail pressure problems. Proper maintenance and clean diesel fuel are essential for extending pump service life.
For diesel repair shops and distributors, understanding HP4 specifications, applications, and repair options helps ensure the correct replacement solution.
Learn more about Denso HP4 294050-0123 specifications, applications, failure symptoms, and repair guide.