Code P0088... bad rattle after replacing everything

[Supa]

I want to start by saying Hello as this is my first post after recently buying a 2004 Dodge Ram 2500 and so far the forum has been a great wealth of helpful knowledge! However after doing a solid chunk of maintenance to the truck I've hit a wall and can't seem to get past it. Any advice would be greatly appreciated!

I'm getting code P0088 (high fuel pressure at the rail) and a loud injector knocking sound.

Recent maintenance/upgrades include the following:

1. Replaced the FCA (both new or old ones don't make a rattle sound when you shake them and there doesn't seem to be a difference in how the engine sounds if you disconnect the wire harness connector)
2. Replaced the fuel pressure relief valve
3. Replaced the fuel rail pressure sensor
4. Installed new FASS fuel filters and dropped the fuel tank to ensure it wasn't contaminated. It's super clean and the FASS platinum system is only about a year old.
5. Installed rebuilt injectors from InjectorsDirect.com (I know we should have gone new but this was all we could afford and their warranty seems legit)
6. Installed new Cummins injector connector tubes (part #4929864). Though I did notice that the tubes look DIFFERENT than the old ones we took out.

Before we did all of this work the truck would emit some serious grey smoke from the exhaust whenever we gave it a decent amount of throttle. Replacing the injectors fixed that issue completely. The truck seems to run smoother and have more power, but the injector knock is still LOUD.

We bought the truck just a few months ago and the previous owner said they found algae in the fuel tank and that's when he had it professionally cleaned and the FASS system installed. So it does sound like the system was contaminated. We've run a few different fuel/oil cleaners (Stanadyne, ) in an attempt to fix the issue before we did this work and they kind of helped with the smoke but not the noise.

At this point it sounds like maybe the injectors are faulty or maybe the injector tubes aren't fully compatible... or even the CP3 pump could be failing. We're on the Big Island of Hawaii and the local dealership wants $300 to look at it. There aren't really any other diesel shops here unless we drive a couple hours so we've been trying other options but now we're stuck. Any ideas or suggestions would be GREATLY appreciated.

Thank you!

 

[Ozymandias]

Are you be able to monitor the rail pressure?

No tunes on the Truck (sure)?

Stock turbo and intake/airfilter?

A sophisticated scanner like Autoenginuity at hand that can show real time data not just a code?

Did you get the right injectors, as 2004 was the change between 305hp and 325hp Engine, which one do you have?

 

[Supa]

Thanks for the reply! I tried to edit my post to add that it's all stock but it won't let me... says something about my post seems like spam?

The truck seems to be all stock except the FASS Platinum lift pump. I'm no mechanic but everything I've gone through pretty much all says Bosch and looks original. I doubt it was ever tuned but I'm not sure.

I've done a VIN lookup and it looks like it was built 2003-09-19 and is the High-Output version at 325 HP. I was pretty sure I ordered the right injectors but I will double check. The VIN is 3D3KU28C14G119160 in case that helps.

I know we should probably get a better OBD scanner, we have a cheap one that shows basic codes but doesn't seem so show fuel pressure (I tried).

Thanks!

 

[HPSimpson]

Welcome to TDR your Ram, Cummins troops here have lots knowledge and how to help solve most problems!

 

[Ozymandias]

You can Download the build sheet here.

https://fcacommunity.force.com/RAM/s/equipment-listing

Yes it seems that you have the 325 engine, the label on the engine would tell you for sure.
Because I did not know yet that the 2004.5 started so early in 2003.

 

[cerberusiam]

Check the build date again, on the driver side door end at the bottom, look for Date of MFR. It will xx-xx format not with a day in it. The build sheet says it has a 48RE, that did not start shipping until 01-04 in the Federal trucks with the 325\600 engine. Either this is the case of the VIN being wrong or you got the wrong build date. Since they don't list HP on the build sheet just HO engine that could be a 305 or 325, but, a 305 in 09-03 was manual gear box only.

None of that really matters if you have an electrical issue. Injector rattle and knock with reman injectors is a fact of life, depending on where you got them you might have just paid for junk. When idling pull the FCA connector again and see if the noise changes, if it does and sounds like a washing machine full of marbles the FCA is working properly or close to it. If you still have a knock after plugging FCA in, try disconnecting all battery cables, tie the grounds cables together, hook the other cable clamp to the ground cable and drop the other cable end on the ground. Let it set for at least an hour to discharge and reset the ECM. If you still have a knock that sounds like a bad rod in a gasser you have an injector hanging open.

 

[Supa]

I checked the build date on the door and it shows "Date of mfr 9-03"... so go figure, it seems our truck doesn't match what is expected.

And I did check the FCA connector a few times with the original and new FCA. Each time you can't tell a difference when idling and pulling the cable harness... no change at all.

I will try your battery disconnect idea and will let you know how that goes. I appreciate your input and suggestions!

 

[cerberusiam]

Is ti a manual or auto truck? That might not even matter if stuff has been switched. However, auto trucks at that time would have been the 265 HP SO engine, only manuals would have the 305 HO.

Is there and engine tag on the driver side front of the valve cover that lists engine specs or is it gone also? Exactly what injectors did you order? For the Mfr date or did you use the ESN off the data tag?

While you are checking make SURE the RP sensor plug was not put in backwards, it will fit back wards and never work right. Also check that harness for any rodent damage or just 16 year old wiring problems.

 

[Ozymandias]

If you pull the FCA connector it should rattle like an old john deere, really really rough.
If there is NO change in sound of the engine then there is something wrong with the FCA, as with diconnect it the railpressure should immediately ramp up to 20K psi around.

 

[Supa]

It's a 4-speed auto and I just verified by looking at the tag on the valve cover (see pic below) that it is the high output 305 horsepower version. I don't know much about the history of the truck so it's possible it was swapped from a manual at some point.

I bought 5.9 2003-2004.5 REFURBISHED FUEL INJECTORS from InjectorsDirect (https://www.injectorsdirect.com/product/5-9-2003-2004-5-refurbished-fuel-injectors/) as it seems they are the right ones.

It's possible that the Rail Pressure Sensor could be on backwards (either by me or the previous owner), what direction should it go on? Right now I think the clip on the harness is facing the front of the truck.

Oh yeah, one thing that seemed odd to me and I meant to mention this in the original post. The fuel pressure relief valve and connecting fuel line get REALLY hot as soon as the engine starts. I saw someone else's post online and it seemed like that may have pointed to a bad Rail Pressure Sensor. What do you think?

Lastly, whether I use the original FCA or the new one, there is no change in how the truck runs or idles. It is loud, knocks, and has a rough idle. I suppose it's possible the new FCA I got was faulty as well...

 

[cerberusiam]

Sounds like it is bypassing fuel if it gets hot right away and probably bad. Possibly it is leaking so much the ECM is commanding fuel rail pressure to keep up, or, it is bypasssing because rail pressure is maxxed out. Hard to tell but it is a candidate for replacement.

Right injectors for the engine, even if they are remans. Until you can solve high RP won't know how good they really are. Trans is not right which means the ECM was programmed to switch from a manual to an auto, that leaves open the possibility of a pooched programming job. Agian, no good way to tell without some scanner tools.

RP plug should have a clip on one the harness side that slips over a catch on the engine side, unless one or the other broke off and then you have to just look at it to see how it should fit together.

 

[Supa]

Well the rail pressure relief valve is a brand new Bosch unit so it shouldn't be bad right? I suppose I could try to put the old one back in and see if that changes anything after we replaced all the other things.

The Rail Pressure Sensor plug is definitely on the right way, the clip prevents it from going on the wrong way so that is good.

The wire harness around the fuel rail seems old but nothing looks to have frayed wires or anything that makes me think it's damaged.

So I did more testing on the FCA to see the actual voltage it's getting. This is based on a test I found online:

Disconnect the Fuel Control Actuator (FCA) harness connector.
Connect an incandescent test light across the Fuel Control Actuator driver circuit and the Fuel Control Actuator return circuit at the fuel control actuator harness connector.
Observe the test light.
The ECM will perform a self test of the circuit which should momentarily flash the test light brightly, one time, approximately 20 seconds after being connected.​

I don't have an actual test light so I figured I'd use my multimeter. That should work right? So I connect the multimeter leads to the FCA harness and when I turn the key to ON (two clicks but not starting the engine) it gets 8 volts of power and does NOT bump up to 12 volts after 20 seconds like it's supposed to (based on the test above). Maybe I'm missing something but it kind of seems to me like the ECM isn't sending enough power to the FCA.

Again, I appreciate everyone chiming in with suggestions and advice!

 

[Ozymandias]

There are bad China PRVs out there, mainly on the known platforms.
They even copy the box of it.
Search the forum for more info about that.

Testlight or multimeter sometimes make a difference as the ECM is checking the circuits for resistance- that a multimeter can't provide.
But also - be very careful with testlights around the ECM as it can fry it.

 

[Ozymandias]

Do you work with the factory service manual??

 

[cerberusiam]

If the rail PRV is new then it is hot because RP is maxxed and it is bypassing. Is the RP sensor new also?

The FCA control is PWM, unless you have the correct tools you won't be able to get any meaningful readings with a multi-meter. Meter likely does not have enough load for the system test either. Need a test light and all that really does is validate the circuit is good. If you do not get that flash on a test light that could be the problem source, the FCA control circuit. Are you getting any codes still? Only the P0088?

The next place to look is the A & B ECM connectors, 03 was a bad year for the harness side connectors. Really, any year older than 10 the connectors could be the issue, either with corroded off pins or just bad connections in the connector.

 

[Supa]

Ok so I borrowed a test light and connected it to both ends of the FCA harness but no light turned on. I connected the test light to the battery and the light came on as it should. So it seems maybe the ECM isn't sending the right signal to the FCA? Does that point to the ECM needing a rebuild or replacement? I tried to disconnect the wire harness to the ECM to at least clean the connectors but couldn't figure out how to remove it. More to research as usual...

The PRV and RP sensors are new. And the problem persists with the old or new sensors.

Yes, we only have error code P0088, nothing else.

I'm not 100% sure here but I did try putting the old FCA back and it seemed to make the PRV even hotter quicker.

Thanks!

 

[cerberusiam]

ECM A & B connectors are secured with a single bolt in the center of each connector then they just unplug.

 

[Ozymandias]

You - can - not - diagnose a bad ECM or anything around that engine with a testlight, you need to follow the factory manual to examine that fault.

The more you rip apart the more possible faults you have in the end from doin so.
Use proper diagnostic, according to the manual, follow them step by step to find the fault.
It is totally nonsens to use the parts gun on a fully electronically controlled engine.

You need Autoenginuity, Snap-on or another decent Scanner to run system test, see what the ECM sees from its sensors and so on.

Sorry.

 

[dieselshadow]

You - can - not - diagnose a bad ECM or anything around that engine with a testlight, you need to follow the factory manual to examine that fault.

The more you rip apart the more possible faults you have in the end from doin so.
Use proper diagnostic, according to the manual, follow them step by step to find the fault.
It is totally nonsens to use the parts gun on a fully electronically controlled engine.

You need Autoenginuity, Snap-on or another decent Scanner to run system test, see what the ECM sees from its sensors and so on.

Sorry.

This really needs to be re-posted. Very good point Ozzy. One must have a gun, not a knife, when in a gun fight. (bad example, but everyone can get it.) You need the proper tool for the job.

 

[Supa]

Thanks for your input guys. At this point it sounds like we need to take it to the dealer and pay the $300 for them to diagnose. I've already spent too many long days on this and it just doesn't make sense to spend a bunch more $$ on a high-end scanner.