RDI Power uses Alliant Power fuel injection components on many diesel repairs, especially on Ford and Navistar engines with HEUI injection. Alliant Power supplies new and remanufactured injectors and related parts, and its coverage for the 7.3 and 6.0 Power Stroke and their Navistar relatives is deep. We install those parts in Brooksville as part of a complete diagnosis, not as a guess.
How HEUI injection works
HEUI stands for hydraulically actuated, electronically controlled unit injector. Instead of a fuel pump creating injection pressure, a high-pressure oil pump pressurizes engine oil, and the engine computer opens each injector electrically. That oil pushes a plunger inside the injector to fire fuel into the cylinder at high pressure. It is a clever design, and it makes the injectors only as healthy as the oil system and electronics behind them.
Engines that use it
- 7.3 Power Stroke
- 6.0 Power Stroke
- International DT466E
- Navistar VT365 in International trucks and IC buses
What fails and why
7.3 Power Stroke
Injector O-rings harden and leak, injector solenoids wear, and the under-valve-cover harness can cut power to an injector. The injector driver module controls the injectors and can fail on its own. Low high-pressure oil can look like a bad injector.
6.0 Power Stroke and VT365
Injectors stick when oil deposits build up on the internal spool valve, a problem called stiction, which is worst on cold starts and with old oil. The FICM supplies the voltage that fires the injectors, and when its output drops, injectors misfire. High-pressure oil leaks starve the injectors of the oil they need to fire. Coolant contamination from a failed oil cooler makes all of it worse. Our Power Stroke service page goes into the 6.0’s other weak points.
How we diagnose before replacing
- Injection control pressure: desired versus actual high-pressure oil, to rule out leaks and pump problems.
- FICM or IDM output: voltage that fires the injectors.
- Cylinder contribution and balance tests with diagnostic software, including Ford IDS on Power Stroke engines.
- Oil condition: old, thin or contaminated oil causes HEUI problems, so we look at it closely. See oil and lube service.
- Wiring and connectors to each injector.
Choosing the right part
Matching injectors to the engine, its model year and its calibration matters. A mismatched injector, or a set with uneven flow, causes rough running and smoke. Alliant Power offers new and remanufactured options, and we choose based on the engine, its mileage and how the old injectors failed. For common rail engines, we compare Alliant Power options with Bosch components and pick what fits the job.
Installing it right
Injectors go in with new seals and O-rings, and with injector cups or sleeves inspected or replaced where the design uses them. We fix high-pressure oil leaks, correct electrical faults, change the oil and confirm FICM or IDM output before starting the engine. Then we road test and recheck balance data. Ford owners can read more on our Ford diesel page, and International owners on our International truck page.
If your Power Stroke or Navistar engine is missing, smoking or hard to start, book a fuel system diagnosis. We will show you the test results before recommending injectors, and we will fix what caused the failure.