1340944 CAT HEUI Fuel Injector – High‑Frequency Solenoid Stability for 3126B/C7/C9 Engines | OEM Direct Replacement
1. Product: 1340944
2. Compatible Equipment: Diesel Fuel Injection Systems
3. Manufacturer: Aftermarket OEM Replacement
4. Condition: Brand New, Fully Tested
5. Origin: ABOSEDE Diesel
6. Shipping period: 3-5 business days
7. Payment terms: T/T, Western Union, PayPal
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Product Introduction
Every injection event in a HEUI system begins with an electrical pulse-a rapid current rise that must overcome the solenoid's inductance to lift the armature and open the poppet valve. The quality of this electrical‑to‑mechanical conversion determines injection timing consistency, especially as engine speed increases and the available time between injections shrinks. The 1340944 injector is engineered for high‑frequency solenoid stability, delivering consistent armature lift and poppet opening across the full RPM range-from idle to governed speed. Its solenoid assembly features a low‑inductance winding and a fast‑demagnetisation armature that ensures the magnetic field collapses completely between pulses, preventing the residual magnetism that can cause poppet sticking or erratic timing. For 3126B, C7, and C9 engine operators, this injector provides a reliable electrical‑to‑hydraulic interface that ensures the ECU's timing commands are executed accurately, pulse after pulse, even under rapid acceleration or fluctuating loads.
📊 Technical Data – Solenoid‑Focused Parameters
| Parameter | Specification |
|---|---|
| Part Number | 1340944 (Caterpillar) |
| Technology | HEUI – high‑frequency solenoid stability |
| Peak Injection Pressure | 1,586 bar (23,000 psi) |
| Intensifier Ratio | 6.5 : 1 |
| Nozzle Type | SAC – 7 × ø0.14 mm orifices |
| Spray Cone Angle | 146° (±1.5°) |
| Needle Lift | 0.28 mm (nominal) |
| Solenoid Inductance | 1.2 mH (±5%) – low for fast current rise |
| Solenoid Resistance | 0.85 – 1.05 Ω @ 20°C |
| Pull‑In Current | 16 A (minimum) |
| Hold Current | 5.0 A (PWM‑controlled) |
| Armature Demagnetisation Time | ≤ 0.15 ms |
| Dynamic Flow Rate | 460 – 500 cc/min @ 100 bar test pressure |
| Connector | 2‑pin Deutsch, gold‑plated |
⚙️ Solenoid Stability – The Foundation of Consistent Timing
The 1340944's solenoid performance is achieved through three engineering choices:
Low‑inductance winding – The solenoid coil uses a bifilar winding technique, where two parallel wires are wound together. This reduces the coil's inductance without changing its resistance, allowing the current to rise faster when the ECU applies voltage. Faster current rise means the armature lifts sooner, reducing the timing variation caused by battery voltage fluctuations. In practice, the 1340944 achieves a 10‑15% faster current rise than standard HEUI solenoids.
Fast‑demagnetisation armature – After the current is removed, the armature must demagnetise quickly to allow the return spring to close the poppet. The 1340944's armature is made from a cobalt‑iron alloy with low coercivity-meaning it loses its magnetism almost instantly when the current stops. This prevents residual magnetism from holding the armature in a partially open position, a condition that can cause delayed closing and over‑fueling.
Gold‑plated connector terminals – While seemingly minor, the connector terminals are gold‑plated to a thickness of 0.5 µm, ensuring low and stable contact resistance. High contact resistance can drop the voltage reaching the solenoid by 2‑3 volts, significantly slowing the current rise and delaying the injection timing. Gold plating resists corrosion and maintains low resistance even after repeated connection cycles.
Why solenoid stability matters at speed : At 2,500 RPM, the time between injections is approximately 6 ms. A 0.2 ms delay in armature lift represents a 3% error in injection timing-enough to affect combustion phasing and reduce fuel efficiency. The 1340944's stable solenoid response keeps this error below 0.05 ms, even under varying electrical loads.