Intermittent low power and engine clatter

[ARigutto]

In the last 500 miles my 2003 Dodge Ram 2500 5.9 4x4 auto SO has developed intermittent engine clatter especially while accelerating from a stop and it is usually accompanied with low power too until I get on the throttle. The engine has just under 10,000 miles on it since I rebuilt it and I replaced the injectors with Dynomite Diesels reman economy set. I went and adjusted the valve lash the other day as a last ditch effort before considering have an issue with the injectors. As far as I know the cp3 is factory so it has about 179,000 miles on it now. I do not have any tuners on the truck and haven’t don’t anything to make more power yet. I initially only noticed the sometimes when I started pulling away from a stop but after a few day I started noticing it cruising at highway speeds around 70mph and it also had a surge that made the truck feel like it was accelerating and then it would let off and it just kept doing that even at different speeds. Like I said it is also intermittent so sometimes it will do it the first trip of the day and be fine the rest or while cruising it’ll just come back and then disappear. I am not sure what else it could be and I know the injectors are still under warranty but I am not sure if it is an injector or something else. If anyone has any ideas I would be really happy to hear them.

Thank you very much for you time.

 

[Darkbloodmon]

Reman injectors are a huge red flag, I would have them checked before the warranty runs out. Make sure you read the fine print on the warranty and accurately document the running conditions. What company wants to warranty out a set of used injectors? (no one)

Another potential cause could be the APP sensor or FCA. But I would most definitely send the injectors out before loading a parts cannon on your own dime.

 

[p-Bar]

You spent all that time rebuilding the engine. You stuck those cheap injectors in . Pull them out and send them back for testing. See if you can get your money back and buy BBI's.

 

[ARigutto]

Reman injectors are a huge red flag, I would have them checked before the warranty runs out. Make sure you read the fine print on the warranty and accurately document the running conditions. What company wants to warranty out a set of used injectors? (no one)

Another potential cause could be the APP sensor or FCA. But I would most definitely send the injectors out before loading a parts cannon on your own dime.

Do you have any recommendations to test these things in the truck to at least narrow down the possibilities?

 

[ARigutto]

You spent all that time rebuilding the engine. You stuck those cheap injectors in . Pull them out and send them back for testing. See if you can get your money back and buy BBI's.

Maybe, they seemed like a good brand from research I had done on them. Maybe I was wrong but I’ll see what I can do. It’s just another part of the process I guess.

 

[Darkbloodmon]

Do you have any recommendations to test these things in the truck to at least narrow down the possibilities?

The APP sensor is a linear potentiometer that needs to be calibrated/clocked when installed. Here is a link to ThroughBred Diesel for the product itself (sensor) on that same page you will see a tab for the installation in which they demonstrate the install and calibration procedure.

For the FCA based off of what you've noted thus far with your symptoms I wouldn't recommend unplugging it to test and drive around on. The FCA is a metering valve for injection pressure, unplug it and you will have maximum pressure. Typically you can unplug an FCA for starting issues etc. Common sense tells me It wouldn't be advisable to drive at the speeds your noticing symptoms at while you're getting max rail pressure. My advise would be to get a known good FCA and swap it in to confirm.

Take this with a grain of salt, I would be looking at the injectors first and foremost. Neither of these sensors are cheap but they are relatively easy to swap. Do you know if the manufacturer will pay shipping and testing? If not these would be more worth while than swapping or testing either of these sensors mentioned to be potentially related to your symptoms.

The reman injectors are the elephant in the room, don't waste a piston over a sensor send out the injectors.

 

[BigPapa]

Maybe, they seemed like a good brand from research I had done on them.

Back in the day, Dynomite Diesel was probably one of the top choices, and they may still be as good as most. I don't think p-Bar was necessarily saying anything about them so much as that you used their ECONOMY injectors. Typically companies carry ECONOMY injectors simply as a low price product. These injectors are usually farmed out to another builder and aren't held to the same standards as their in-house injectors. This is true of most companies, not just Dynomite Diesel.

Now, all that said, the BBI injectors have a very loyal following here on TDR due to their outstanding performance, durability, and customer service.

 

[p-Bar]

Yeah sorry about that. Cerb is rubbing off on me

 

[Darkbloodmon]

The APP sensor is a linear potentiometer that needs to be calibrated/clocked when installed. Here is a link to ThroughBred Diesel for the product itself (sensor) on that same page you will see a tab for the installation in which they demonstrate the install and calibration procedure.

For the FCA based off of what you've noted thus far with your symptoms I wouldn't recommend unplugging it to test and drive around on. The FCA is a metering valve for injection pressure, unplug it and you will have maximum pressure. Typically you can unplug an FCA for starting issues etc. Common sense tells me It wouldn't be advisable to drive at the speeds your noticing symptoms at while you're getting max rail pressure. My advise would be to get a known good FCA and swap it in to confirm.

Take this with a grain of salt, I would be looking at the injectors first and foremost. Neither of these sensors are cheap but they are relatively easy to swap. Do you know if the manufacturer will pay shipping and testing? If not these would be more worth while than swapping or testing either of these sensors mentioned to be potentially related to your symptoms.

The reman injectors are the elephant in the room, don't waste a piston over a sensor send out the injectors.

Totally forgot to hyper link the sensor itself while writing this response, my bad. Here it is.

 

[ARigutto]

I got in contact with Dynomite diesel last week and they told me if an injector was faulty they would replace it. I asked them if they would be able to let me upgrade them to 50% overs just as an example and they said that we would probably be able to figure something out. I know guys are saying to go with BBI but we all know how expensive injectors get and I still have heard lots of good things about Dynomite, so I will probably be sticking with them if we can figure something out about the warranty. I decided to take off my oil filter and cut it open to determine if there was any chance for a mechanical failure in the engine like a spun bearing an there was a virtually no metal and I have over 3,000 miles on this oil change. I also did a test drive with a Cummins mechanic from work and he said that the truck was misfiring at idle and then when I was accelerating the noise I was hearing was a fuel knock. I decided to change the fuel filter just in case since it has almost 10,000 miles on it. The issue still hasn't gone away so I want to pull the injectors and send them back to Dynomite to get tested, but I want to do some more testing to make sure it isn't another issue that I may be overlooking. I was wondering if anyone had any other ideas for what I can do to test the injectors? I know there is a big testing procedure from Cummins to test for the injectors bypassing too much fuel but with my current living situation I don't have the tools or a place to do those tests. Is it best for me to just send the truck into a shop to get properly diagnosed or is there enough evidence to condemn the injectors?

 

[Darkbloodmon]

I really would stop hesitating and send the injectors out. The majority of the time if there is a running condition issue with these trucks its fuel related. Example being every approx. 200K mi Truck on marketplace that's had a rebuild because of an injector failure not being addressed soon enough.

Again, BBI and be done with it. It's your call.

The only test that is worth it at this point is an injector kill test to isolate which injector is misfiring (send them all out)
You can just carefully disconnect the solenoid wires from each injector one by one, turn the engine over and listen for the knock to go away. It's a very similar to a misfire test on a modern coil plug ignition system, pull a coil/swap it to see if the misfire goes away or moves to a different cylinder.

.02 : I wouldn't be looking at 50% overs until I get a grasp of my current running condition issues. This is a newly rebuilt engine yeah? Wait for the issues and hiccups to settle out before adding in new variables beyond the stock parameters. If you start adding in parts like that you run the risk of not being able to isolate out changes due to its addition and issues separate of it.

 

[Ozymandias]

With some good software like AutoEnginuity or of course wiTech you can switch off injectors one by one like you want.
You also can run a cylinder distribution test to find a bad injector.

So every dealer can do this two tests.

 

[ARigutto]

Thank you all for your help. I have stopped driving the truck and am sending the injectors out. With any luck I should be able to drive again in a few weeks.

 

[ARigutto]

I really would stop hesitating and send the injectors out. The majority of the time if there is a running condition issue with these trucks its fuel related. Example being every approx. 200K mi Truck on marketplace that's had a rebuild because of an injector failure not being addressed soon enough.

Again, BBI and be done with it. It's your call.

The only test that is worth it at this point is an injector kill test to isolate which injector is misfiring (send them all out)
You can just carefully disconnect the solenoid wires from each injector one by one, turn the engine over and listen for the knock to go away. It's a very similar to a misfire test on a modern coil plug ignition system, pull a coil/swap it to see if the misfire goes away or moves to a different cylinder.

.02 : I wouldn't be looking at 50% overs until I get a grasp of my current running condition issues. This is a newly rebuilt engine yeah? Wait for the issues and hiccups to settle out before adding in new variables beyond the stock parameters. If you start adding in parts like that you run the risk of not being able to isolate out changes due to its addition and issues separate of it.

I agree with you which is why when I rebuilt the engine U just left it stock. I wanted it to break in before doing any changes.