I recently acquired a 2000 D 4.7. It seems in really nice shape and runs great but it starts really weird. When I turn the key, it cranks over for quite a while without firing both when it's cold and after it's warmed up. If I crank it over for 2-3 seconds then wait for 2-3 seconds, then crank it again, it fires right up on the first revolution or two but if I hold the key and keep it cranking instead of cranking it twice, it'll crank for 6-8 seconds before starting. I figured maybe the fuel system is dirty so ran a can of Sea Foam through it with no noticeable change. After the D starts, it runs great, no hesitation or any obvious problems. It cranks over fast and I've noticed nothing strange with the charging or battery system.


When I initially turn the key, I hear the fuel pump run then shut off but it almost seems like the fuel isn't getting to the injector rail or something. If I do the quick crank then wait for a second, maybe it charges the fuel system a second time and gets the fuel pressure up? Has anybody else had any similar problems? I couldn't find anything by searching but did find a ton of useful info for someone new to the Durango Thanks in advance for any thoughts, ideas and help.

 

I would start off and check the starter relay by swapping it with another same relay and then check the connections to and from the starter. Also if you can check pressure at the fuel rail so you can make sure its getting adequate pressure. I would assume if its fine after startup that its a starter problem and not a fuel system problem.

Also does it sound like regular cranking or is there a grinding like noise because in which case it could be a flywheel problem.

 

it almost sounds to me like the anti-drainback valve in the fuel pump is shot, this means you can either live with it until the pump dies or replace the pump (the valve is built into the pump unfortunately).

 

It cranks over fine at normal speed with no strange noises other than it not firing while cranking. The anti drainback thing sounds like it could be very likely. Thanks for the help, I'll check the pressure at the rail before cranking, after a short crank and after it's running to see what it's doing.

 

It's either the fuel pump is loosing all prime or you need to replace your spark plugs. Use the cheap Champion Copper plugs gapped at .040


Pressure at the rail when it is off can be none, you will have to check while it is running, but ensure it is above 50 psi. If air is in the line from a bad check valve the prime is going to be air at first. Personally, I think it's your plugs.


Also clean your throttle body and IAC.

 

I'm having the same prolems with my 02 Durango. I've put in all new sensors one by one and nothing fixed it. That is until did a test my local mechanic told me about.
I took a can of starting fluid spray and while the engine was running at normal temp and then spray the starting fluid lightly around the fuel rails and injectors.
Sure enough that was the problem in my case. I found the fuel rail was leaking at the cross over tube in the front of the engine. So to verify it . I purchased some JB Weld and put a good bead around each side and let it dry for an hour. I then turn the key on and primed the fuel rail. Sure enough it started just like it always did. I spent a fortune on all different sensors and was ready to install a new in tanke fuel pump I had just purchased. (I was lucky enough to be able to send it back for a refund).
So before you go and start buying parts check your fuel rails and the cross over tube. Hope that helps some one