daneflynn

Hello All. I have a 2000 grand cherokee with a 4.0 liter.
Fault code p3000/p3001/p3006...misfires in the number 1 and 6 cylinders.. any ideas on what to attack first based on you guys training and experience with this. I would love to hear any ideas. Thanks

tjwalker

First thing I would do is verify fuel pressure. The "random misfires" indicate a systemic problem, rather than anything isolated to just those cylinders.

For a 2000, you should have 49 psi, plus or minus 5 psi. Pressure must be tested with a gauge; no shortcuts. Many parts stores will rent you this gauge inexpensively.

How is your idle? Another suspect for the P0300 are vacuum leaks.

daneflynn

She is idling rough but doesnt stall out....fault codes show misfire on those cylinders 1/6 if fuel pressure was the issue would it show those two only????thanks i will check it today.

melton32

i have a 1999 grand cherokee and i have a code of P0351,i have replaced the coil pack 6 times and replaced the cam position sensor and still have the same code and is still running rough,i was told it could be my PCM,has or does anyone have this same problem and have you fixed and how did you fix it....please help for i am out a bunch of money already and its breaking me....thanks

Kalali

Unless that was a typo the misfire codes are P0301 and P0306 for cyl 1 and 6, respectively. The only common link I can think of is the coil rail since the coils (three of them on the rail) fire 1&6, 2&5, and 3&4 at the same time.

tjwalker

After researching this, I agree with Kalali. Cylinders 1 & 6 fire together. If you have misfires on those two cylinders ONLY, then the coil rail is absolutely the primary suspect.

Good luck and keep us updated!