Engine surging at idle when cold

[EDankievitch]

My 2013 has developed a very strange issue. When it’s cold ,engine temp below 125 when you come to a stop while in drive the engine will surge. Best way to describe it if you have ever run a 71 series Detroit with a sticky fuel rack. The engine RPM will go from 575 to 850. Put the truck in neutral and the idle settles out. Put it back into drive and it starts the gallop all over again. It also seems to be putting itself into regen way more often that it use to.
A ran a few tanks with the Cummins approved Panther piss injector cleaner and lube which I thought helped until last evening. It surges enough that it’s almost like the converter is locking an unlocking with the engine surge. Funny thing is it will not do it in reverse. I don’t have a code reader available at the moment. But the last time I checked for codes nothing came up. Nor has it tripped the CEL lamp.
Any thoughts? I just turned 127k miles. All filters are new. Off idle it runs normal. Once the engine warms above 145 degrees it runs normal...

 

[DonFitzwater]

FCA getting tired?

 

[EDankievitch]

I was thinking along those same lines. What is throwing me is why doesn’t it do it in reverse?

 

[DonFitzwater]

I was thinking along those same lines. What is throwing me is why doesn’t it do it in reverse?

Weird.....sounds like a transmission related problem in that case. Maybe Transengineer will chime in.

 

[EDankievitch]

Ok update it does it in reverse also. It will gallop if you let it idle in gear even with foot off the brake. Maybe the FCA is starting to die. I’m going to see if Geno’s has one tomorrow.

 

[DonFitzwater]

Ok update it does it in reverse also. It will gallop if you let it idle in gear even with foot off the brake. Maybe the FCA is starting to die. I’m going to see if Geno’s has one tomorrow.

That makes more sense to me. Genos always has them on the shelf in my experience.

 

[manganos]

I'm having a similar issue. At idle RPM jumps around 100 rpm. While driving it surges making it difficult to drive. Looking at my MM3 monitor when I press the accelerator it doesn't affect RPM until 5% instead of right off. 2016 3500 68RFE deleted 77k miles

So far I've replaced the TPS (pedal assembly), changed out both fuel filters and ran injector cleaner.....

Let me know what you find out. Mine is at a indy shop right now.

 

[EDankievitch]

I’m just waiting for Geno’s to ship the New FCA out. Holidays always slow things down.

 

[manganos]

Thank you sir. I've had good luck with Genos in the past!. Can you post a video of your symptoms by chance?

 

[EDankievitch]

Ok. So new FCA installed so far it seems to have solved the surging issue.. so far. I need a much colder morning to be sure. I will say that the engine did run way smoother with the new FCA. Time will tell. Sorry I couldn’t get it to fail for a video weather this past week has been very warm and the truck was almost behaving as it always does when temps above 40. We should have a good cold snap next few days that might give me a good test. Time will tell. I’ll report if I have something else to report.

 

[manganos]

Thanks for the update

 

[ProLean]

My '14 will do this when the engine temps aren't up to normal yet and I have the EB on. As soon as I turn the EB off, it goes away. I have just thought I needed to wait for the temps to rise and then put the EB on. Might be sticking a bit within the turbo actuator and that's affecting the rpm's. ?

 

[DonFitzwater]

My '14 will do this when the engine temps aren't up to normal yet and I have the EB on. As soon as I turn the EB off, it goes away. I have just thought I needed to wait for the temps to rise and then put the EB on. Might be sticking a bit within the turbo actuator and that's affecting the rpm's. ?

When it's cold it's best to use the exhaust brake to accelerate warmup.

 

[EDankievitch]

2nd cold morning an all is good. It’s looking more an more like the FCA was in fact the issue all along.

 

[TomBrady]

2nd cold morning an all is good. It’s looking more an more like the FCA was in fact the issue all along.

Thanks for the info. I was having the same symptom, ordered the part from Geno's and it was the fix for me as well.

 

[EDankievitch]

Biggest pain was getting the electrical plug connection to unlock an pop off with out breaking it. And the close clearance between the FCA and fuel line. If you can get a long reach toques socket and Allen wrench your life will be easier. I used a 1/4” drive socket set and it was tight. Couldn’t get a straight line up on the screws. But I got it done an didn’t strip anything out.

 

[DonFitzwater]

FYI, if you are going to replace an FCA, get the FCA and the pigtail from Genos. The connector is known for fitment problems and then you can just cut it off!

 

[EDankievitch]

So with the New FCA installed the truck has been running smoother. However last night while stuck in traffic and fully up to temp, had been driving for 200 miles. It started with the surging every time I stopped and let it idle. At one point I I slipped the toe of my foot under the throttle peddle and pulled it fully up to the idle stop and everything settled out. Now I'm wondering if the throttle position sensor is starting to fail.... I'll keep everyone posted...

 

[mfurrh55]

Thats what it sounds like, i had a lincoln Mark VII do that , replace TPS and all was good

 

[EDankievitch]

Ok I give up. The surge is there almost all the time now. Get stuck in traffic and every time you let it idle in gear it will surge. It also seems to be going into regen way more often. I should add that my last tank of fuel MPG’s were way down. But we did have snow and I was towing a trailer for 230 miles. But it did use way more fuel than normal. When it surges you can smell that it is in regen. I’m not showing any codes. Tow a trailer at speed and it runs good. Sit in traffic for 15-20 min and it starts in. That shot of snow having to drive slow and it did it for almost 25 miles. I’m in process of relocating and don’t have access to a good scan tool anymore. Only thing I keep thinking is a bad injector, they do have 130k miles on them. But when it runs and you don’t let it idle or take it out of gear when stopped I really runs good. Just under load it will surge. Turning the engine brake off lessons it some but it’s still there.
Am I missing something? Could it be a bad injector?