4JK1 Diesel – Hard Start Issue, Even After Injector Service

[BrokeLizard]

Hey guys,
I’m working with a 4JK1 Isuzu diesel engine (used in D-MAX), and I’m facing a persistent hard start issue.

Here’s what I’ve done so far:

• Injectors serviced and reprogrammed
• Battery is strong and starter cranks normally
• Engine runs fine once started — smooth idle, no smoke, good power

What’s weird is that the engine cranks for several seconds before catching.

Anyone dealt with this on the 4JK1 or similar common rail setups?

Would love to hear if you’ve solved this issue before. Appreciate any leads!

[Moi_Mc]

@BrokeLizard

…e.
Here’s what I’ve done so far:

Injectors serviced and reprogrammed
Battery is strong and starter cranks normally
Engine runs fine once started — smooth idle, no smoke, good power

What’s weird is that the engine cranks for several seconds before catching.
Anyone dealt with this on the 4JK1 or similar common rail setups?
Would love to hear if you’ve solved this issue before. Appreciate any leads!

Try unplugging the fuel rail pressure sensor and cranking. Some ECUs will default to a “limp” pressure value, which may tell you if the sensor is the issue …not a fix, just diagnostic