van shudders and vibrates at approximately 2,500 or 2,000 RPMs?

2017 RAM PROMASTER
93,000 MILES • 3.6L • 6 CYL • 2WD • AUTOMATIC
Avatar
CORY2427
  • MEMBER
  • 293 POSTS
Van at about 2500 or 2000 rpm’s range vibrates and shudders drop it in manual mode does okay throws a bunch of codes Po300 random misfire detected.
Po325 knock sensor 1 circuit bank 1
Po303 cylinder 3 misfire detected
Po456 evap leak detected small
Po457 evap leak detected fuel cap
but replaced both knock sensors and connectors to them and replaced all coil packs and plugs.
Nov 28, 2023 at 3:06 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

If there is a vacuum leak, it could cause poor drivability issues. Since you replaced the items mentioned, what codes are now present? Did they all return or only certain ones?

Also, did this start all at once? Have you checked the fuel pressure to make sure it is within the manufacturer's specifications? If not, here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If you have a live data scanner, with the engine running and at operating temperature, check the short-term fuel trims and let me know what they are.

Let me know.

Joe
Nov 28, 2023 at 8:57 PM
Avatar
CORY2427
  • MEMBER
  • 293 POSTS
Have no way to test live data and yes, these codes are present after doing all the work.
Nov 29, 2023 at 7:50 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

It's interesting the same codes have returned. Here is what I'm going to suggest: First, make sure there are no engine vacuum leaks.

Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

If there is nothing found, we need to be specific to cylinder 3 on the next checks. It may be related to a fuel injector or a compression issue in that specific cylinder.

You do have the P0300, so that is why I'm thinking a vacuum leak and suggesting the check. Is cylinder 3 the only specific cylinder misfire?

Let me know.

Joe
Nov 30, 2023 at 6:45 PM
Avatar
CORY2427
  • MEMBER
  • 293 POSTS
Yes, I went got gaskets so replaced lower and upper intake gaskets replaced cylinder 3 injector took my knock sensor connectors apart and soldered them together put everything back together erased codes took it for a spin yesterday. Now it seems to be doing fine and no engine light, yet all codes are gone.
Dec 1, 2023 at 4:20 AM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi Cory,

It sounds like it has been fixed. Is that correct? Let me know.

Take care,

Joe
Dec 1, 2023 at 9:27 PM
Avatar
CORY2427
  • MEMBER
  • 293 POSTS
Yes so far seems to be.
Dec 2, 2023 at 6:41 PM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

Thanks for the update. If anything changes, let me know.

Take care,

Joe
Dec 2, 2023 at 7:56 PM