Diesel Jerking on acceleration

[darylm74]

I just picked up a 2021 Diesel. I was coming off of an F250 and still wanted something that might pull a small boat or U-haul. I won't get into the dealer situation but thinking it might have something to do with it but either way, the jeep started jerking on acceleration tonight. I stopped and when I accelerated again, no issue. I got some EDT to hopefully keep it in shape but worried this may be the pump issue. Anyone had this?

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[Deleted member 59498]

Not much help here, just to report I have not had that happen.

 

[darylm74]

Thinking it might be fuel injectors being dirty which is a common cause of jerking but only experience with gas. Hopefully the EDT cleans it up. I already ordered a bumper, winch and lift kit. I did all the work on my 2011 JKU and was looking forward to doing it on the JLU. Maybe should wait to see if there are a lot of mechanical issues.

 

[Deleted member 59498]

Yeah are just had a spot of bad fuel. I had some bad fuel in the fall that froze on me, probably had some water in it or something I guess.

Maybe even sat on lot for a while with old diesel? I use EDT now myself.

 

[GrayGunner]

Thinking it might be fuel injectors being dirty which is a common cause of jerking but only experience with gas. Hopefully the EDT cleans it up. I already ordered a bumper, winch and lift kit. I did all the work on my 2011 JKU and was looking forward to doing it on the JLU. Maybe should wait to see if there are a lot of mechanical issues.

I’d try diesel extreme vs the EDT here. Hopefully it’s bad fuel if you don’t have any alerts for water in fuel or a CEL. Mine did this a bit before the CEL, and the fix wasn’t quick… This is a wet connection in the harness off the PCM. No bueno. Connection was tight but the gasket failed.

 

[darylm74]

@GrayGunner Thanks for the heads up. I just got the EDT so will try that first. Luckily I don't drive a lot as I work from home. I will look for the connector and check it out. DId you have to replace the wiring harness? I had to do that on my son's SAAB. Definitely was a PITA.

 

[GrayGunner]

@GrayGunner Thanks for the heads up. I just got the EDT so will try that first. Luckily I don't drive a lot as I work from home. I will look for the connector and check it out. DId you have to replace the wiring harness? I had to do that on my son's SAAB. Definitely was a PITA.

Yeah, a new harness, though not an entire harness like I think you did with your SAAB. Fixed under warranty at the dealer so it’s on the record if I get another gremlin down the road. Got lucky, the wait for part availability was 2 weeks instead of 4-5 like the dealer stated. They’ve seen this issue across the board so it’s not just a diesel thing. However, they also fixed my oil cooler leak while I waited…which definitely seems to be isolated to us ?.

 

[driventoadventure]

---CAVEAT: Below feedback is based on not experiencing this on my Ecodiesel, but having fairly extensive experience dealing with injector issues on an early 2000s Cummins HO and a couple 6.0 psd---

For what it is worth, EDT is more lubricity and prevention focused and won't really work to restore injectors. You would need a more restoration/cleaning-focused additive like Marvel Mystery Oil or HSS Diesel Extreme like @GrayGunner mentioned.

That said, if its not happening frequently then I would also assume a fuel issue first. Depending on how many miles it has you may want to change the fuel filter (unless wherever you bought it from did recently) as your first preventative step. Just be sure you prime it thoroughly after changing the filter. Also, depending on how much history you have access to, to help measure the worry of the fuel pump issue see if it has ever been run empty of fuel as that's one of the major ways to aggravate the presumptive root cause of failures in these pumps.

Being in Florida, moisture intrusion is also a likely worry - especially with all of the recent flooding y'all have had. Try checking all of the fuses and relays along with the PCM harness(es) in the Engine bay as @GrayGunner said.

Along the moisture checking vein, even if you don't change the fuel filter, you should still drain the water separator anyways to inspect if there is moisture in your fuel, as that would cause jerking like you had.

Welcome to the club! This engine is incredibly fun in these Jeeps.

(edited to add) I don't think we have a specific water separator per se so I am referencing opening the water drain from the fuel filter housing.

 

[darylm74]

I put a double dose of EDT in and didn't have any issues. I took my far better half our for a spin through a park and had a gasser wrangler blasting music come up behind me (Seriously was just a nice quiet family park) . He tried to race me at a stop light, getting on the highway, and I left him sitting. No issues with jerking. I told my wife I was checking out the additive. ????. Either way no jerking and after my acceleration (race cough cough) test, my much better half was happy with the top down, salt air, Florida beach night out. I wish I had the Jeep in time to plan to head over to Daytona for beach days. We are already ordering a Jeep tent for next year.

 

[Deleted member 59498]

I bet it was just a one off after sitting on the lot, either moisture or such. Glad it blew the gunk out and is doing well.

If you like the torque can get a banks pedal monster will make the throttle response feel a bit more powerful. It takes the small lag out of the pedal really cool and noticeable. Still its 300 bucks so may or may not be worth it to some.

 

[darylm74]

@Scott.B I looked at the Banks' products after some YouTube videos. First thing is the bumper, winch and lift kit. I can justify those to my wife, well at least to some extent (trails, gtfo during hurricanes, etc). I guess I should be a lawyer lololol. The other parts are going to be a bit of a stretch. One purpose for buying the Jeep was she could drive it since we got rid of the camper on our move (due to her job) to Florida (not complaining). Driving the monster F250 Crew Cab which had a lift 3" lift kit scared her a bit, even though it had all of the side warnings. She was much more comfortable in my F150 and prior JK. I will have to ease her in on any other mods, mainly financially since she is a CPA. There are some nice trails down here that are an hour away and she loves the backroads so maybe can "sell" her on those eventually. Right now she has agreed to help me with the bumper/winch/lift but probably an excuse for her to lay out in the sun. Not going to complain about a wrench girl in a bikini out getting some sun...who wouldn't take that?

 

[darylm74]

So no leaking gaskets and using Diesel Extreme. What I am noticing is that the jerk seems to happen when the A/C is on, but not when off. I noticed it on our trip from Tampa to Key Largo and back. We had the top down (and got rained on) but never had an issue for part of it. I think it is too early to tell but seems to be a possibility. I have been watching the voltage but it never drops below 12. I have seen where alternator issues can cause jerking. I reviewed other threads to get an idea and seems it never drops much below 14.

I have the auto-stop/start feature and I know it is supposed to have a heavier duty alternator system. Maybe something is up with that? Traveling to TN to visit family across Memorial day (and maybe wheel) which is a 10 hour drive north. Will be testing things out along the way. Oh will be towing a small load of stuff I had stored at my mom's too so more experiments and plenty of time to gather them.

 

[darylm74]

Update. I took the Jeep from Tampa to my Mom's in TN just west of Chattanooga with an empty utility trailer across Memorial Day. It gave me some of the same issues but worse. On the way back I had probably 2500lbs between items in the Jeep and in the trailer. Accelerating, especially uphill felt like it was trying to jerk my teeth out. I can't really tell if it is the engine/pump or the transmission. I tried to shift manually but that didn't make a difference as it acted the same way. This really makes me thing it is the engine/pump. I don't know if the prior owners used Diesel Xtreme (oh had the leaky bottle issue....that is another story), something similar or not. I am hoping I get the recall soon but worried damage may have already been done and just not thrown a code yet. Accelerating on flat ground doesn't seem to cause an issue, but the slightest incline and I get some kind of jerk, even if it is mintor on a slight grade.

 

[Deleted member 59498]

Could be pump I suppose but generally they go completely out from what I have read. Have you made an appointment with the dealer?

 

[darylm74]

Waiting for the dealer to call me back. I was away Memorial day and back to Pittsburgh for daughter's graduation so playing phone tag. As for the pump completely going, that is also what I found through others' experiences. I would say transmission but doesn't seem to be any particular gears and acts the same in manual mode. More to come after I finally get it in to see the doctor.

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