Occasional long crank to start? 2.7

[DrunkSlug]

Hey TeamRoxor, any insight would be great!

This is a 2025 roxor, about 1500 miles on it if I had to guess. Occasionally I'll have to hold the key, it'll crank for a good five second then catch and start right up and idle/drive fine. Turn it off, 50/50 chance it'll do that again or it'll just start up the second I bump the key.

I did drain the fuel filter/water separator. Air filter is clean. Has happened for 2-3 tanks of diesel now so not contamination issue.

 

[Longslyde]

When key is turned on, a relay should run the tank pump for a few seconds. This pressurizes the supply system. If that relay is functioning abnormally, or intermittently, the engine would have to crank until the ECU sees either RPM or oil pressure. I'm not sure which one the Roxor uses there, but it's one of the two. I'm guessing oil pressure. If the relay doesn't turn on, you'd have to crank the engine long enough for the ECU to see the trigger. See if you can hear the pump run when you turn the key on. If it does, and still takes a long crank, then I'm not sure what's happening. Good luck getting 'er figured!

 

[USMC]

Drunk, do you have the diagnostics manual?

Is the engine cranking when key is in start position? YES

Is MIL Lamp on in the instrument cluster? NO 1) Ensure diesel fuel is present in the fuel tank
2) Ensure there is no leakage in the fuel system
3) Ensure in-tank fuel pump & relay are working
4) Ensure no air is present in the fuel system, bleed fuel system if required 5) Ensure intake air heater is heating up
6) Ensure main relay is functioning
7) Ensure diesel fuel injectors are functioning as per spec.
8) Ensure there is no visible fuel contamination 9
9) Ensure air filter is not clogged

 

[Dohat]

There is no fuel pump in the tank on the 2.7 roxors. Open the bleed screw at the top of the filter housing and pump it to make sure all the air is out of the filter.

 

[USMC]

Sorry about that, I pulled the wrong manual!

And I thought I was good in reading and comprehension! Back to remedial classes for me.

 

[Dohat]

Your good it happens to all of us.

 

[lost1wing]

It does sound like an air leak in the fuel system until you said, on a restart it may also do it. Is that restart moments after you turn it off? If so, an air leak is not too likely. I would look at the oil pressure system. Did you change the oil? Did you install the correct oil filter?

If your restart is an hour or longer, it could be an air leak in the fuel system. You said that you drained the water from the filter. Is that tight?