Pump code P0216 is gone, but now a slight intermittent engine flutter at idle

[01_Cummins_4x4]

I do not notice the slight flutter while in Drive or Reverse. 

 

I have no idea as to how many miles are on the injectors as I just bought the pickup 3 weeks ago. The pickup only has an original 197k on it. 

 

It didn't do this until after I installed a new injection pump and checked the valves - .010 intake valves, and .020 exhaust valves.

[Mopar1973Man]

Hook up a live data tool and report back idle speed and engine load on a fully warmed engine.

[01_Cummins_4x4]

I just wanted to put this out there, that before the new injection pump got installed, my idle used to be 750ish rpm. 

 

If the truck is cold, it doesn't flutter, only after it's warmed up. 

 

I would think if it's an injector issue, it should do it all the time and not intermittently.

 

I'm leaning towards air in a fuel line or I'm wondering if it could be the fuel temp sensor in the new VP44 pump?

 

 

[Mopar1973Man]

Worn-out injectors typically show signs more so when warmed up than cold. Still, in all I need to know the idle speed and engine load to verify more of the injectors which are still possible and don't always create a steady problem but random ones as well.

 

[01_Cummins_4x4]

[Mopar1973Man]

Injectors are junk. Engine load is zero percent and idle is above 800 RPM this is true because the injectors are opening too early and ECM has cut fuel too ZERO and still can't hit 800 RPM +/- 5.

[01_Cummins_4x4]

But why would it show up only after an injection pump change? My FASS 165 is still running the same fuel pressure at 17-18 psi.

 

The injection pump I took off was still working and only had code 0216. It just wouldn't let me build any boost until the engine was warmed up to 115* due to the previous owner starving it of fuel due to a plugged fuel filter and it probably seized up the timing piston in the pump.

I still have a good set of OEM Bosch stock injectors from my other 01 pickup. I guess I can go through the hassle of installing them and see if the issue persists or goes away. 

 

I just find it odd that it happened after a VP44 pump change. If the injectors are bad, you'd think that they would've done it with the old pump as the load on the engine is still the same as it was before. 

Edited May 1 by 01_Cummins_4x4

[01_Cummins_4x4]

My friend who has been building diesel trucks for over 17 years listened to my injectors, and the #3 injector isn't receiving enough fuel pressure from the new pump to help it pop off normally. It is clacking but intermittently. 

 

My friend has another friend that had the same exact issue with the miss at idle after the engine warmed up, and it was his VP44 pump causing the miss at idle on his Cummins.

 

I pulled the pump off in 45 minutes and will be calling them tomorrow morning and see what they're going to do ASAP, since this pickup is my only rig to get to work in.

 

 

[Mopar1973Man]

 

Pump creates the same pressure to all but the injectors are worn out. That is because number 3 is popping to low and dumping pressure. If the spring and shim are worn out the pressure will drop on that cylinder. Injectors are a way cheaper to deal with even pop testing is like 7 to 15 dollars a injector to be tested.

 

Still have high engine idle and zero engine load still pointing to bad injectors. No injector will last beyond 100k miles. Pull yours out and test I bet money they are all below 293 Bar (4,250 PSI) which is lower limit. 310 bar (4,500 PSI) is normal.

Edited May 2 by Mopar1973Man

[Tractorman]

I am very interested to hear the final outcome - what the actual problem is.

 

- John

On 5/1/2024 at 7:41 AM, 01_Cummins_4x4 said:

It didn't do this until after I installed a new injection pump and checked the valves - .010 intake valves, and .020 exhaust valves.

 

Did you make any valve adjustments, or did you just check them?  Just trying to rule out any other potential cause.

 

- John

[Tractorman]

@01_Cummins_4x4, have you heard anything regarding your VP44 injection pump from Oregon Fuel Injection?  I am assuming that you have talked to them about  your engine idle flutter.

 

- John

[01_Cummins_4x4]

I rechecked the valve clearances and they are correct. 

 

I find it illogical that if an injector is bad, that it should've had this same issue with the other pump. I narrowed it down to the #3 injector as it wasn't firing in a normal rhythmic pattern, and a pump wouldn't isolate this issue to just one injector.

 

The injectors are OEM Bosch with 150hp nozzles, and I suspect they could be the original injectors from 2001. 

 

I pulled the injector apart and one of the thin shims in it was broken in two pieces. I ordered a new set of DAP SAC 150hp injectors, and I'm just waiting for them to show up. I requested them to be set at 320 bar.

[Tractorman]

Sounds like a good approach.  Good extra step your part for re-checking the valve clearance. 

 

I agree that a faulty injection pump likely would not isolate one injector.  The only way it could would be if there was a problem in the distributor head or in the constant pressure valve for the injector firing #3 cylinder.  I would think a problem there would show up while the pump was being operated on the test stand.

 

Please let us know the results after you install the new injectors.

 

- John

[01_Cummins_4x4]

Brand new set of DAP 150hp SAC injectors (set to 320 bar) installed this last Friday night, and so far everything seems normal and great again.

[Tractorman]

Excellent!

 

- John