Long cranking before start.

[econgump]

Has anyone figures this out? 2016 3500 6.4l, 90K. Same problem. New battery, new plugs 5 months ago. Took to dealer for $400 of diagnostics.!!! Pressure checked fuel system, told bad fuel pump. Installed new delphi fuel pump, did not solve problem. I'm now $800 in and still takes several turns of key to start. I have tried turning key on and off 4-5 times to prime system, hear fuel pump go one for 3-4 secs, still really hesitates to start.

 

[TEC Tactical]

I was told by a REAL mechanic (Who actually listened to all the info from me) at a dealership that my issue seemed to be a sticking injector. I recently took a trip from GA to NY ad back and used two bottles of cleaner and low and behold. I have not had that problem for over a month now. Fires right up.

He said the sticking injector gave a "Not ready to start" issue. That made sense as when it would start I could smell the fuel in the exhaust.

 

[fitteenhundred]

Which cleaner did you use?

 

[Slinge]

Maybe try Key on to run....turn off.....Key on to Start. That would run the fuel pump twice before trying to start.

 

[TEC Tactical]

Which cleaner did you use?

Red Line 60103 SI-1 Complete Fuel System Cleaner​

 

[breal201999]

I’ve just started having the same issue. Cranks for about 3 seconds, turn key off. Turn back on 2nd time, cranks 3-5 seconds and starts up. Was “sticking injector” with injector cleaner the only seeming solution? Or anyone else finally know the problem?

 

[Tach_tech]

I’ve just started having the same issue. Cranks for about 3 seconds, turn key off. Turn back on 2nd time, cranks 3-5 seconds and starts up. Was “sticking injector” with injector cleaner the only seeming solution? Or anyone else finally know the problem?

When does it happen? First thing in the morning, after sitting a couple hrs etc?

 

[breal201999]

When does it happen? First thing in the morning, after sitting a couple hrs etc?

It hasn’t happened at cold start on the morning after sitting overnight. It has only happened when my wife gets off work. She is a teacher, so it sits in the parking lot a good 8-9 hours.

 

[Ken226]

Do you have a scan tool, or AlfaOBD?

Check the live data PIDs for fuel trim. A weak fuel pump and low fuel pressure would likely show up in the fuel trim as the PCM adds pulswidth to the injectors to try and maintain the a/f ratio.

 

[breal201999]

I’ve just started having the same issue. Cranks for about 3 seconds, turn key off. Turn back on 2nd time, cranks 3-5 seconds and starts up. Was “sticking injector” with injector cleaner the only seeming solution? Or anyone else finally know the problem?

Just a follow up for anyone else researching this issue. I added some Lucas fuel injector cleaner at last fill and it hasn’t had the hard start symptom since. Maybe sticky injector??

 

[pilotype]

Same problem here with my 2016 5.7 Ram. Is NOT the battery. Mine is much worse during summer months when its warm or hot out. I am thinking its a failing cam or cranks sensor. No codes. I hate just throwing money at it but intermittent problems are hard to diagnose.

 

[Sherman Bird]

I've been chasing this for awhile now, what did you end up doing to fix it?

I wonder if it has EVER dawned on ANY tech to perform a fuel pump waveform test on an oscilloscope? THAT is THE GOLDEN standard, and it removes ALL the guesswork! You know.... a DEFINITE ANSWER!?