MCR
Rail Blank | MCR | Denso Common Rail 4JJ1, YD25, 4D56, 4N15, 1VD-FTV, 4M41
Rail Blank | MCR | Denso Common Rail 4JJ1, YD25, 4D56, 4N15, 1VD-FTV, 4M41
Taxes excluded. Shipping calculated at checkout.
Complete the install
Couldn't load pickup availability
4JJ1 | YD25 | 4D56 | 4N15 | 1VD-FTV | 4M41
Replaces the factory mechanical relief valve on Denso common rails so the rail holds commanded pressure under load instead of bleeding off. On a tuned engine the relief valve is the part that caps rail pressure and drops it under towing or wide open throttle, and no amount of calibration fixes that with the valve still in the rail. One part covers the Denso rail pattern across six engines.
Fitment
| Engine | Vehicles |
|---|---|
| Isuzu 4JJ1 | D-MAX 2008 to 2012 and 2017 to 2020, MU-X 2012 to 2020, Holden Colorado RC 2008 to 2012, Rodeo RA7 2007 to 2008 |
| Nissan YD25 | Navara D22, Navara D40 |
| Mitsubishi 4D56 | Triton 2005 to 2015, Challenger |
| Mitsubishi 4N15 | Triton MQ and MR 2015 on |
| Mitsubishi 4M41 | Pajero, Triton 3.2L |
| Toyota 1VD-FTV | LandCruiser 70 Series 01/2007 to 08/2016, 200 Series pre-DPF |
Quick check: Denso rails only. Not Bosch, not Delphi. The 1KD has its own 1KD rail blank. Not sure? Add your VIN or State and Rego to the order notes and we will confirm before dispatch.
What It Does
- Removes the mechanical relief valve, so there is no crack-open point below the ECU's target
- Holds commanded rail pressure under load, towing and at wide open throttle
- Lets the tune command higher and more stable rail targets
- Built for engines with upgraded nozzles, pumps and turbos
What's in the Box
- 1 x MCR rail blank, Denso rail thread
Machined and threaded in house by MCR in Thailand and black coated. Use a suitable thread sealant, clean the seat and torque to specification.
Fitting Notes
- Direct replacement for the factory rail relief valve. Clean the seat, fit with thread sealant, torque to specification, prime and leak check.
- Monitor commanded versus actual rail pressure with a scan tool during testing.
- Tune required so the ECU manages rail pressure with sensible targets and limits.
- Not recommended on a stock vehicle.
Safety and Compliance
Removing the mechanical relief deletes a factory over-pressure path. Incorrect tuning or a hardware fault can damage injectors, pump or rail. For off-road and competition use where permitted.
Stock and Lead Time
In stock and shipping same or next business day. If we are waiting on a shipment from MCR, allow 1 to 3 weeks and we will confirm an ETA.
Shipping and Payment
- Free express shipping Australia wide. Full tracking included.
- Buy now, pay later. Afterpay, Humm, Klarna and Zip.
- International shipping available. Message us for a quote.
Frequently Asked Questions
Q: Is tuning required?
A: Yes. Once the mechanical relief is gone the ECU is the only thing managing rail pressure, so the calibration needs sensible rail targets and limits.
Q: Can I run this on a stock engine?
A: Not recommended. Rail blanks are for tuned engines with upgraded fuelling and monitoring.
Q: Does it fit Bosch or Delphi rails?
A: No. This MCR blank is for Denso common rail systems only.
Q: Does it fit a 1KD?
A: Not this one. The early 1KD has its own rail blank.
Q: Is it road legal?
A: Typically no. Intended for off-road and competition use where permitted.
Hold Rail Pressure. Six Engines, One Part.
MCR rail blank for Denso common rails. Tune required. Free express shipping Australia wide.
Disclaimer: Common Rail Cowboys is not affiliated with Isuzu Motors, Nissan Motor Co., Mitsubishi Motors, Toyota Motor Corporation or Denso Corporation. Fit by a competent diesel technician. Fitment and compliance are the buyer's responsibility.
