Help with P0300, P0301

Reply Subscribe

Thread Tools

Search this Thread

Mar 5, 2015 | 06:59 PM

#16

tjwalker

CF Veteran

Joined: Nov 2010

Posts: 5,840

Likes: 117

From: In the middle of Minnesota!

Year: 1999

Model: Cherokee

Engine: 4.0

Quote:

Originally Posted by Jessejeep27

Hello, I've read these posts. Any thoughts on a 2001 Grand Cherokee also getting misfire codes? I'm getting 0302. and 0301.

I have replaced spark plugs. 6 month old plugs a lot of carbon.
Tested the voltage to each injector.
Did the Noids test, pulsating light.
All checked out to my manuals specs.

Compression test done and good.

Would you suggest replace fuel injectors (1 and 2) on my year Jeep as well?

Jesse, as you have a Grand Cherokee, it's best to post in that forum. These forums are platform specific. Here's a link.

https://www.cherokeeforum.com/f5/

If I were you, I would swap injectors 1 & 2 with 3 & 4 and see if the fails follow to the swapped cylinders. Replacing the injectors without trying the "swap and follow" strategy is not wise. You can often get fooled. Your coil rail is also in play here. Good luck!

Mar 5, 2015 | 09:10 PM

#17

Jessejeep27

Newbie

Joined: Feb 2015

Posts: 7

Likes: 0

From: Upper Michigan...way up

Year: 2001

Model: Grand Cherokee

Engine: 4.0 L Straight 6

Thank you tjwalker for my vehicle specific link (Grand Cherokee) and your advice, I too thought swap before replace to confirm.

I truly appreciate your advice.

Mar 6, 2015 | 09:08 AM

#18

xjforlife

Junior Member

Joined: Jan 2015

Posts: 57

Likes: 0

From: Pennsylvania

Year: 2001

Model: Cherokee

Engine: 4.0 Power Tech

Does this happen on warm starts if so its just some vapor lock its because the feul injector rail is on the same side as the exhaust manifold when its left parked the exhaust boils the feul inside the injectors causing air bubbles it then pumps the air bubbles in without feul and it throws codes it's harmless though just annoying

Mar 6, 2015 | 11:55 AM

#19

skife

Seasoned Member

Joined: Nov 2013

Posts: 469

Likes: 3

Model: Cherokee

Quote:

Originally Posted by Grip

Dont waste time with injector cleaner. Swap the injector.

If it becomes P0302, you need in injector.

Might as well buy the upgraded 703 injectors since all 6 are cheap.

Quote:

Originally Posted by Grip

Have you looked into a CPS?

Quote:

Originally Posted by xjforlife

that would be cylinder 3, there is a TSB about it.

Mar 6, 2015 | 12:41 PM

#20

Evolution860

Thread Starter

Newbie

Joined: Feb 2015

Posts: 16

Likes: 0

From: CA

Model: Cherokee

I noticed that when I clear the code, the jeep seems to drive and idle better. As soon as that code pops up, then it starts getting a little rough. Wondering if an exhaust leak could be the culprit?

Mar 6, 2015 | 10:48 PM

#21

Evolution860

Thread Starter

Newbie

Joined: Feb 2015

Posts: 16

Likes: 0

From: CA

Model: Cherokee

Installed a new PCV today, code still came back. Ive heard that the 96 4.0 doesn't have an EGR valve. Wondering if maybe an exhaust leak may cause the misfire??

Mar 7, 2015 | 11:29 PM

#22

Evolution860

Thread Starter

Newbie

Joined: Feb 2015

Posts: 16

Likes: 0

From: CA

Model: Cherokee

UPDATE!! Installed a new fuel filter.... didn't even clear the code.. when I started it up, the trouble code went away all by itself... hopefully it stays that way!

Last edited by Evolution860; Mar 7, 2015 at 11:31 PM.