Starting problems - fuel pressure sensor/pump/filter?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

birchit

Member
Joined
Feb 10, 2016
Posts
49
Reaction score
5
Location
Germany
Ram Year
2015 Power Wagon
Engine
Hemi 6.4l
Hi together,

PW 2015 6.4L 87500mls
I have some problems during starting. My PW need longer than normal to start. Coils and sparg plugs are new, battery is okay.

What can cause this problem?

Does someone know where the fuel sensor (Pressure) and the fuel filter is located?


Thanks to all and stay healthy!

Birchit
 

Daw14

Senior Member
Joined
Nov 29, 2017
Posts
2,027
Reaction score
2,077
Ram Year
2014
Engine
5.7 hemi
.
 
Last edited:

Bob Macknight

Senior Member
Military
Joined
Feb 3, 2019
Posts
185
Reaction score
166
Location
surprise az
Ram Year
2015
Engine
6.4hemi
mine started to act up like yours,turned out it was the key fob batteries this was at around 78,000 miles.Changed out batteries and all is good
 

TRad

Member
Joined
May 31, 2019
Posts
62
Reaction score
59
Location
Minnesota
Ram Year
2018
Engine
6.4 Hemi
All the fuel goodies are in the tank. I have seen the check valve go and it lets gas drain back into the tank. Truck will crank longer to start. Should be a air valve on the fuel rail to hook up a pressure gauge, pressure should not drop when you turn off truck. Watch the valve, fuel will squirt out when you hook up gauge. Hot engine and gas don't mix well. Good luck!
 
OP
OP
B

birchit

Member
Joined
Feb 10, 2016
Posts
49
Reaction score
5
Location
Germany
Ram Year
2015 Power Wagon
Engine
Hemi 6.4l
Hi guys,

indeed during the start sometimes it cranks longer than normal, like it seems to have a fuel pressure problem - but not regulary. I will first check the key fob batteries which will be the easiest thing to do. But to be honest I cannot believe that this could cause such a problem. But would be nice if it is that simple.

I use the same fuel as always with the same octane. The battery is still very good after 5 years. The european batteries aren't that good at all....if I decide to change it, what suggestion to you have for a new starter battery? Optima? We had during offroad racing the best experiences with the optima products. What size do you suggest for the PW? The do not show a right size on their website...

Bevor I dismount the whole tank to reach the stuff I will use the pressue gauge. Can you tell me where the air valve is located at the fuel rail and how high the pressure has to be?

Thanks!
 

62Blazer

Senior Member
Joined
Dec 11, 2019
Posts
1,067
Reaction score
1,255
Location
Midwest
Ram Year
2016
Engine
6.4
Please don't continue to throw parts at it and hope you get lucky as some very basic diagnostic work and checks can help point out the problem. Can't count how many times I see people who don't want to spend a couple hundred $$ having a good shop diagnose the problem but will drop $500 replacing random parts that don't fix the issue.

Quick check on the fuel drain back or pressure when starting. Turn the key on but don't start the engine. This will turn the fuel pump on and let it prime the system. Maybe even cycle the key a couple times......turn the key on and let it set for around 5 seconds, turn key off and back on for 5 seconds, and then start. If it always fires right up then start looking at the fuel system. Next step would be to put a fuel pressure gauge, or at least buy a decent diagnostic tool that reads parameters like fuel pressure.
 
OP
OP
B

birchit

Member
Joined
Feb 10, 2016
Posts
49
Reaction score
5
Location
Germany
Ram Year
2015 Power Wagon
Engine
Hemi 6.4l
Thanks 62Blaze for that help - I will try that. But the last few weeks everything seems to be fine. No starting issues at all...strange.
 

Tinman454

Senior Member
Joined
Apr 7, 2021
Posts
184
Reaction score
277
Location
Saskatchewan
Ram Year
2021
Engine
6.4
Is there a fuel filter you can change? On other vehicles a dirty or plugged filter will cause the same problem you are describing.
 

SeppW

Senior Member
Military
Joined
Jan 19, 2020
Posts
484
Reaction score
299
Location
Northern VA
Ram Year
2016
Engine
Hemi 6.4L
Asking the obvious, but have you scanned it yet to see if there are any fault codes? Could give you place to start at. As for a battery, I replaced the OE FLA battery with a Northstar AGM. Odyssey AGMs are allegedly excellent batteries too. Odyssey is sold in Europe, assume Northstar is as well.

Recommend Alpha OBD for a diagnostic tool, can all be ran on smart phone. Need the interface for OBD port too, recommended interface on Alpha OBD Web page. Also gives ability to change configurations in various modules.
 

BillyGoat

Member
Joined
Dec 21, 2020
Posts
77
Reaction score
47
Location
SE MI
Ram Year
2017
Engine
6.4
Not to hijack the thread, but my truck sometimes starts then shuts off right away. The other day it took 3 tries, but 95% of the time it’s fine... any suggestions?
 

SeppW

Senior Member
Military
Joined
Jan 19, 2020
Posts
484
Reaction score
299
Location
Northern VA
Ram Year
2016
Engine
Hemi 6.4L
Not to hijack the thread, but my truck sometimes starts then shuts off right away. The other day it took 3 tries, but 95% of the time it’s fine... any suggestions?

Run a scan and see what trouble codes are set if any for starters then work from there. If it were a carbureted engine, I'd say vapor lock, clogged fuel filter, ignition coil. With EFI it's hard to say. Could be anywhere in fuel system and electrical circuit that controls it.
 
OP
OP
B

birchit

Member
Joined
Feb 10, 2016
Posts
49
Reaction score
5
Location
Germany
Ram Year
2015 Power Wagon
Engine
Hemi 6.4l
NO trouble codes at all....the most problem is a bad starting battery....
 
Top