2015 5.7 Hemi in over my head?

[WhaChoNameIsMan]

Unsure where to begin. The truck started missfiring and had trouble starting. I will attach all the codes and explain what trouble shooting has been done. The Fuel pump was changed but only made things slightly better.

It seems like she is starving for fuel. If I prime it using my tools she will start right up, run good. Then, it starts to die down. When it shuts off, It won't turn back on until you prime it again. There is a restriction somewhere in the fuel system

Prior my purchasing the truck this kit was installed. The install was done April 2024.
The heads were sent off at the same time. And MDS delete was done as well.

https://www.amsracing.net/collectio...2015-5-7l-hemi-engines?variant=11532742524964

The missfires I am having are on Cylinders 6, 7, and 8.

Put a larger diameter fuel line on the fuel rail pressure sensor to see if it could put us at the desired fuel Rail pressure. Still didn't fix the problem, it was running smoother, but it still shuts off on us.

6 7 and 8 still misfire 6 7 and 8 injectors play ring around the rosey. I don't know when they want to work and when they don't want to work. Am thinking it could be the fuel injector which seems weird because they come on anytime I command them on. That and I swapped six and eight, with two and four, and it didn't switch which the cylinder was misfiring i tried researching what would cause those injectors to sometimes work sometimes not work.

Fuel trim is single digits which suggests ignition issue. It is also no longer getting any low fuel pressure codes pending active or past.

I keep getting thrown off. Because I have swapped injectors. I have also swapped spark plugs, and coils. I also can't seem to find any issues with wiring. Compression was checked but only on Cylinder 6 and it was good.

The photos on this thread reflect updated codes. If needed I will post original codes as a reply. Any help would be greatly appreciated as I am at a loss.

 

[Bigskyroadglide]

When the kit was installed, did you get a tune of any sort, if so from who?

 

[WhaChoNameIsMan]

When the kit was installed, did you get a tune of any sort, if so from who?

Yes, from Peitz Performance Tunes

 

[Bigskyroadglide]

I'd start with the tuner, first.

 

[Burla]

What was the psi at the back of the engine after the fuel pump. So can you give us a timeline? How long was the truck running fine? Anything changed right before this issue? Post the codes in a nice order. OEM fuel pump?

 

[EdGs]

When the fuel pump was changed, was the tank checked for debris?

So you are saying you put a larger fuel line on because your fuel pressure is weak? A larger line in one spot will not help your pressure, IMO.

What brand fuel pump? It is possible to get a bum pump.

Crud in the fuel rails?

Condition of the plugs?

Not sure if they make an adapter you can plug in to the fuel line and the rail to verify pressure while running.

 

[04fxdwgi]

Yes, from Peitz Performance Tunes

Until you get a gauge on the fuel line to find what actual pressure is, all this is guessing.

Looking at their site, it would appear that they did the tune with an HP Tuner. Have you done anything to modify the tune yourself? I would contact them to see if there is anything in the tune is not "quite right".

There is a possibility the ECM has some problems, like the harness connector may have a bent or loose pin. Or the ECM is going south. Not unheard of.

Have you checked all the harness and the ground connections (all of them).

All the problems seem to point to a harness / sensor / ECM problem

 

[KansasArt]

A larger diameter fuel line will decrease pressure given the same volume.

 

[WhaChoNameIsMan]

There have been several questions asked so I will answer all that I can in a reasonable manner.

Let me start by saying that I am not mechanic and the "I did XYZ" in post is generally referring to a friend that is. The most that I have done to assist is tool fetching and breaking clips. So here is the run down:

I purchased my 2015 ram 1500 5.7 Hemi in November and had check engine light pop on after working perfectly for a little over a month. So i checked the oil and it was just on the add line. So i added some oil.

When i had the codes checked it had one for P0440 (Evaporative Emission System), and the Permanent Codes due to MDS Delete.

The MDS Delete, Cam shaft replacement, and Tune all occured prior to my purchasing thr truck. I believe they were done in 2022 or 2023.

Even with the check engine light on, the truck was running fine and had no issues at all but the light was an eyesore. And I remembered that the fuel cap was found open a day or two prior and figured this could have been the issue.

I then took the truck to a friend at an auto parts store to clear the codes for me. After the codes were cleared the truck died completely and had to be towed after only driving 5 miles. It was hard to start and keep started.

So the troubleshooting began...
The truck started showing different codes such as low fuel pressure codes, missfires in cylinders 6, 7, and 8, no pulse width in same cylinders. Bank 2 air fuel ratio imbalance.

So far we put new fuel rail pressure sensor and a new fuel pump (Delphi Fuel Pump Module Assembly: With Float Arm, Seal) from Advanced Auto. The pump was nearly $400.

These two parts stopped the low fuel pressure codes and now i can get truck to drive but it dies on me. Cylinder 6 7 and 8 intermittently show no pulse width for the injectors. I have swapped plugs coils and injectors with the good ones but the problem remains at 6 7 and 8.

I did a compression test of Cylinder 6 and had good compression. The wiring was checked but not with a fine tooth comb. There were no obvious signs of issues.

As for the Tune I have not played with it all. As far as I know it should be just as it was when purchased. I also spoke to a rep from the Tuning Shop and they assured me a simple code clear would not have erased their tune. As for the pressure testing at the rear or what the larger diameter hose was to achieve I will have to ask as I don't know.

 

[WhaChoNameIsMan]

Also forgot to mention,

The fuel found in the rails was not clean but not horrible. When the tank was removed there were some particulates that we removed prior to reinstalling.

 

[04fxdwgi]

Forgot to mention, is the tune an HP tune or a Diablo tune? Some have written of the Diablo tunes causing problems down the road.
I have a Diablo in mine and have not had any problems with it.

 

[jokerswild206]

Check and make sure your electrical plugs on fuel injectors and coils are clean and pushed all the way on. Also any vacuum lines for cracks,pinches . Plus check the boots on coils. The internal springs sometimes need litter stretching for a good contact on pack to plug.

 

[LONEWOLF64465]

Unsure where to begin. The truck started missfiring and had trouble starting. I will attach all the codes and explain what trouble shooting has been done. The Fuel pump was changed but only made things slightly better.

It seems like she is starving for fuel. If I prime it using my tools she will start right up, run good. Then, it starts to die down. When it shuts off, It won't turn back on until you prime it again. There is a restriction somewhere in the fuel system

Prior my purchasing the truck this kit was installed. The install was done April 2024.
The heads were sent off at the same time. And MDS delete was done as well.

https://www.amsracing.net/collectio...2015-5-7l-hemi-engines?variant=11532742524964

The missfires I am having are on Cylinders 6, 7, and 8.

Put a larger diameter fuel line on the fuel rail pressure sensor to see if it could put us at the desired fuel Rail pressure. Still didn't fix the problem, it was running smoother, but it still shuts off on us.

6 7 and 8 still misfire 6 7 and 8 injectors play ring around the rosey. I don't know when they want to work and when they don't want to work. Am thinking it could be the fuel injector which seems weird because they come on anytime I command them on. That and I swapped six and eight, with two and four, and it didn't switch which the cylinder was misfiring i tried researching what would cause those injectors to sometimes work sometimes not work.

Fuel trim is single digits which suggests ignition issue. It is also no longer getting any low fuel pressure codes pending active or past.

I keep getting thrown off. Because I have swapped injectors. I have also swapped spark plugs, and coils. I also can't seem to find any issues with wiring. Compression was checked but only on Cylinder 6 and it was good.

The photos on this thread reflect updated codes. If needed I will post original codes as a reply. Any help would be greatly appreciated as I am at a loss.

get a factory fuel rail pressure sensor and wiring connector / pigtail .

 

[04fxdwgi]

I would pick up a set of noids to plug into the injection and ignition connectors to get a quick look if they are firing. Even better, an analyzer or oscope to see a sign wave on the connectors and be able to see a dwell and amplitude.

 

[EdGs]

Also, load test your battery with a toaster style tester from Harbor Freight. When batteries go wonky, our Rams do not like it and they can do weird stuff.

Just a very simple test to do, just in case.

 

[Bob Horowski]

Not sure if I missed it, but I do not remember seeing anything about changing the fuel filter?

 

[Wild one]

Not sure if I missed it, but I do not remember seeing anything about changing the fuel filter?

No fuel filter on a Ram,there is a sock of sorts on the bottom of the fuel pump inside the tank,that's about all you get for a fuel filter these days in alot of vehicles

 

[WhaChoNameIsMan]

I ended up taking her to a shop. Let's hope they do me right. I will update with the results so that others who encounter this issue might have a better starting place.

 

[rjbar46]

@WhaChoNameIsMan Any Update??