Denso
4JJ1 DPF +50% Modified Injectors | MCR Performance Nozzles | Isuzu D-MAX, MU-X 2017-2020
4JJ1 DPF +50% Modified Injectors | MCR Performance Nozzles | Isuzu D-MAX, MU-X 2017-2020
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4JJ1 DPF +50% Modified Injectors: Isuzu D-MAX and MU-X (2017 to 2020)
Set of 4. Genuine Denso 295050-2420 bodies fitted with MCR Performance +50% nozzles. Built to order for tuned Euro 5 4JJ1-TC Hi-Power engines.
The Fuel Side of a Tuned DPF 4JJ1
Brand new genuine Denso 295050-2420 injector bodies, opened up on our bench and fitted with MCR Performance +50% nozzles. Same body, same solenoid, same 9F coding as the factory injector, with roughly half again as much fuel per stroke at the same pulse width. This is the only modified injector we build for the DPF 4JJ1: it works on the factory turbo with a sensible tune, and it comes into its own behind a turbo upgrade.
Fitment: Is This the Right Injector?
| Vehicle | Engine | Build dates | Code prefix |
|---|---|---|---|
| Isuzu D-MAX (Euro 5 update) | 4JJ1-TC Hi-Power 3.0L, DPF | 02/2017 to 08/2020 | 9F |
| Isuzu MU-X (16.5MY on) | 4JJ1-TC Hi-Power 3.0L, DPF | 02/2017 to 2021 | 9F |
Quick check: the code on top of your injector starts with 9F. A 72 or 5F code is a pre-DPF 4JJ1 and takes a different injector: see the 4JJ1 +30 injectors or ask us. An A9 code is a 4JJ3.
Not sure? Add your VIN or State and Rego to the order notes and we will confirm before dispatch.
Body
Genuine Denso 295050-2420, brand new. Isuzu 8-98317930-0. Not a recon, not an exchange core.
Nozzle
MCR Performance +50%, nominal flow over standard. Fitted and matched on our bench.
Factory turbo
Yes, with a tune. The remap sets how much of the extra fuel gets used, so a stock turbo build runs a conservative map and still picks up torque.
Turbo upgrade on a DPF 4JJ1: the SAK 44mm and FLEX F55 are catalogued for the 4JJ3 and bolt to the same manifold flange on the DPF 4JJ1, but they are not a bolt-on job on this engine. Expect fabrication for the intake and dump side, a DPF delete, supporting mods and a tune written for the combination. Talk to us and your tuner before ordering the turbo.
Part Numbers
| Denso body | 295050-2420 alt. 295050-2540 |
| Isuzu / GM | 8-98317930-0, 8-97435554-0 |
| Nozzle | MCR Performance +50% |
| Compensation code | Denso 9F code printed on each injector body |
What Else You Need for the Install
- Genuine 4JJ1 Injector Washer and O-Ring Kit. Single-use crush seals.
- New injector-to-cover seals and leak-off clips while the cover is off.
- A tuner booked in. The truck will run once fitted, but do not drive it hard on the factory map.
Standard replacements instead? See the genuine Denso DPF 4JJ1 set. Bodies still good? +50 nozzles only.
Fitting and Coding Notes
- Clean the bores and seat faces, fit new seat washers, torque the clamp bolts to Isuzu specification.
- Enter the 9F code printed on each injector body into the ECU in the correct cylinder position, then run the injector learn procedure.
- Clean-room practice. One speck of grit is enough to stick a needle.
- Installation by a qualified diesel technician recommended.
Stock and Lead Time
Built to order on our bench. Typically 0 to 2 business days to dispatch. If we are waiting on bodies or nozzles, allow 1 to 3 weeks and we will confirm an ETA. On a deadline? Message us before ordering.
Shipping and Payment
- Free insured express shipping Australia wide. Full tracking included.
- Buy now, pay later. Afterpay, Humm, Klarna and Zip.
- International shipping available. Message us for a quote.
Modified Injector Disclaimer
Where a modified or oversized injector is advertised or sold as a Genuine injector, including Denso, the term Genuine refers only to the injector body. It does not refer to the nozzle.
The injector body remains genuine. The nozzle and the overall flow characteristics differ from original OEM specification. Flow percentages are nominal and vary with rail pressure, pulse width and test bench.
Any change to emissions equipment or calibration must comply with the laws that apply to your vehicle and its use.
VIN and Compatibility Disclaimer
When you provide your VIN or rego we will confirm the injector type your vehicle left the factory with. This may not be correct if the injectors, harness or ECU have previously been changed.
It is the customer's responsibility to verify injector compatibility before installation.
Frequently Asked Questions
Q: Do I need a tune?
A: Yes. An ECU remap is essential. The factory map does not know the nozzle changed, and at +50 the smoke will tell you fast.
Q: Will these work on a stock turbo?
A: Yes, with a tune written for it. The tuner runs a conservative map that uses part of the extra flow. You get more torque without the smoke, and headroom for a turbo later.
Q: Is there a +30 for the DPF 4JJ1?
A: No. +50 is the modified injector we build for this engine.
Q: Which turbo goes with them?
A: The SAK 44mm or FLEX F55. Both bolt to the DPF 4JJ1 manifold but need fabrication, a DPF delete and supporting mods with a tune for the combination. Message us before you buy the turbo.
Q: Are these new Denso injectors?
A: Yes. Brand new genuine Denso 295050-2420 bodies fitted with MCR Performance +50% nozzles. No exchange, no reconditioned cores.
Q: Do I code them?
A: Enter the 9F code printed on each injector body into the ECU and run the learn procedure. Your tuner will normally do this with the remap.
Q: Will these fit a 2012 to 2016 or 2006 to 2012 4JJ1?
A: No. Pre-DPF engines use different injectors with 72 or 5F codes. We build modified sets for those too.
Genuine Denso Bodies. MCR +50% Nozzles. Built on Our Bench.
Set of 4 for the Euro 5 DPF 4JJ1 D-MAX and MU-X, 2017 to 2020. Tune required. Free express shipping Australia wide.
Disclaimer: Common Rail Cowboys is not affiliated with Isuzu Motors or Denso Corporation. Injectors should be fitted and coded by a competent diesel technician. Fitment and compliance are the buyer's responsibility.
