Cranks, no start for about an hour after already driving it, then starts right up.

[Anson]

Hi folks. After driving my 2016 hemi just fine, even a block, I turn it off and when I turn the key to start again it cranks but does not start. I usually have to wait about an hour to an hour and a half before it starts again, and then it starts just fine. Once in awhile I can start it right after I shut it off. But typically speaking, I have to wait at least an hour to start again. I replaced the fuel pump with a cheaper Amazon pump about a month ago. I've always had good luck with those. I swapped some relays around to see if it was a relay issue but that didn't work. But I'm not sure if I was hitting the right relays though. Any advice would be appreciated.

 

[Ken226]

I replaced the fuel pump with a cheaper Amazon pump about a month ago.

So, was this pump replacement done in an attempt to fix this pre-existing problem?

Or, did these symptoms start at some point after the cheap Amazon pump was installed?

 

[Burla]

What's a 6.7 hemi gas or diesel?

run any codes?

 

[Anson]

It only gives me some catalytic converter codes. Maybe a sensor? Maybe I need to replace the cats. But I doubt it has anything to do with this problem. Unless it does. I don't know. I never had this problem before. The fuel pump went out while we were driving one day. So we pulled the tank and replaced the fuel pump and it fired right up but now it just doesn't intermittently after it's been driven.

 

[Anson]

This is a gas engine by the way.

 

[Anson]

I should also mention that when I turn the key on I can hear the fuel pump going. It's so strange that there would be something in between the fuel pump and the engine that's keeping this from happening.

 

[Jim BB]

Hi folks. After driving my 2016 hemi just fine, even a block, I turn it off and when I turn the key to start again it cranks but does not start. I usually have to wait about an hour to an hour and a half before it starts again, and then it starts just fine. Once in awhile I can start it right after I shut it off. But typically speaking, I have to wait at least an hour to start again. I replaced the fuel pump with a cheaper Amazon pump about a month ago. I've always had good luck with those. I swapped some relays around to see if it was a relay issue but that didn't work. But I'm not sure if I was hitting the right relays though. Any advice would be appreciated.

Could still be a fuel pump !
I have seen brand new fuel pumps pressurize fuel system run turn vehicle off turn key to run position have pump come on but not create enough pressure let it sit for a while and try again and it starts ! so I would be checking fuel pressure at the rail ! thats just something I would do!

 

[RedSRT4Me]

It only gives me some catalytic converter codes. Maybe a sensor? Maybe I need to replace the cats. But I doubt it has anything to do with this problem. Unless it does. I don't know. I never had this problem before. The fuel pump went out while we were driving one day. So we pulled the tank and replaced the fuel pump and it fired right up but now it just doesn't intermittently after it's been driven.

What are the exact codes its giving?

 

[Anson]

P0420 and P0430

 

[mdc1990zr1]

P0420 and P0430

They are both codes for catalytic converters. Maybe they are plugged. I had a Chevy truck with a bad fuel regulator that cooked my converter. If you don’t take care of the problem before the converter, you will ruin it

 

[Burla]

Easiest fix in the world to dyi fix P0420 for good by moving o2 sensor back, Walmart was selling them for 6 bucks lifetime fix. Alternatively a long trip like 1/2 a tankful and a catalytic converter cleaner is another option, see if either fixes your issue, it is very possible it will. The cleaner needs the cats to get hot to burn off crud, it has to be long trip. Shops wont do that, you need to do it, check the YouTube's.

 

[Sherman Bird]

Hi folks. After driving my 2016 hemi just fine, even a block, I turn it off and when I turn the key to start again it cranks but does not start. I usually have to wait about an hour to an hour and a half before it starts again, and then it starts just fine. Once in awhile I can start it right after I shut it off. But typically speaking, I have to wait at least an hour to start again. I replaced the fuel pump with a cheaper Amazon pump about a month ago. I've always had good luck with those. I swapped some relays around to see if it was a relay issue but that didn't work. But I'm not sure if I was hitting the right relays though. Any advice would be appreciated.

"Luck" is a fickle friend!

 

[chrisg_ky]

Did you find a solution? I'm having a similar situation. Went out one morning to start and it wouldn't start. Replaced fuel pump still wouldn't start. Replaced Tipm,cam, crank and map. After the map sensor I floor the pedal when starting and it sputtered to life and cleared out. Drove for 45mins and died. Took to dealer. They did a cam and crank relearn. Checked pcm voltage which was good. But initially said there was a failure between the PCM and fuse box but never elaborated on it again. then they said they swap the crank sensor back out with the og crank I had in the door in box. I pick it up drive home. Start it the next day and let run for a hr. All good. Dive to town today to buy dog food. Truck starts after going in store. Drive two minutes to Kroger and truck dies I. Kroger parking lot as I pull into spot. Lucky there. Would not start. Sputtered terribly. Left her for the night and I am gonna try to start it tomorrow and drive it straight back home. Can't seem to find a decent mechanic who can do electrical issues.

 

[RedcardRam]

While not related to those codes...I have in the past had a gas cap go bad and this caused fuel to be suctioned and not be able to leave tank properly. I Would have to wait for vaccum to slowly release before driving. After replacement I never had that issue again.

I also had a car where the resistance of coil would change when it heated up causing the vehicle to just crank over.

Again I am NOT saying these are your issues...but something to check. Gas caps are cheap.

 

[HarryS]

put a fuel pressure gage on it when it doesn't start.