Long crank when engine is warm and Fuel pressure drops to zero after engine shut off?

DIDI7154

MEMBER
2002 DODGE DAKOTA
5.9L
V8
4WD
AUTOMATIC
148,000 MILES

My truck starts right up in the morning but after I drive it, and the engine is warm it has a long crank to start. I checked the fuel pressure and when the engine is running the fuel pressure is good. As soon as I turn the truck off the pressure immediately drops to 0. I suspect there’s a leak in the pressure system somewhere. My thoughts are either the injectors or the fuel pump/pressure regulator/ check valve (all of which are part of one fuel pump assembly on this truck). How do I determine if the leak is at the injectors or the pump?

Thursday, October 31st, 2024 AT 12:57 PM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

If an injector is leaking, you will have an engine misfire. It does sound like the fuel pump is getting weak and even though you have good pressure when idling it might drop off while driving under load. Do you have any trouble codes? Here is a guide that deals with hard starting which we should go over for more information.

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

Fuel System Pressure .................... 339 kPa ± 34 kPa (49.2 psi ± 2 psi).

Is this what you got when testing? Please go over this guide and get back to us.

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Thursday, October 31st, 2024 AT 5:52 PM