P0305 Clyinder 5 Misfire

'01 is running really rough and this code is shown. I searched, but nothing with this cylinder. I was getting an Evap code (something dealing with purge) before, but I thought it was the gas cap. Could it be that these are related? I read some where that EGR malfunctions can cause misfires if they cause a loss of vacuum, but I have no idea how that system works. Any help would be most appreciated!!

i have a 00 and had some trouble with it, though not exactly the same things. These links might be worth a read

http://autorepair.about.com/library/faqs/bl010h.htm

http://www.automotiveforums.com/t367657-2000_grand_cherokee_problems.html

the second link is about a grand cherokee, with similar problems.


the 00 and 01 cherokee evap systems have several TSB's, and most likely your problem is somewhere in the evap system leak detection system. With several failure points, its likely you have more than one bad part. My 00 has a bad valve in the filler neck that gets stuck and shits gasoline out during fillups.

It all might be due to batches of high sulphur gasoline corroding the fuel system parts...who knows. Hope this helps a little.

i would out the egr as your problem because the 91 and up models do not have an egr valve.

89xj said:

i would out the egr as your problem because the 91 and up models do not have an egr valve.

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Yep. I was thinking of the EVAP system. Went out and ran through that. Don't know if it makes a difference but when the head was replaced they put the soleniod assembly back in upside-down. The word "Bottom" is even molded into it! I switched that around, checked all the fittings and electrical connections, took the air breather and hoses off and checked all that, replaced those (my TB was surprisingly clean!), got under it and ran through the EVAP hoses back to the gas tank, checked the # 5 injector and looked to see that the fuel rail was on correctly. There was a dead bee right between the rail and the engine block right on cylinder #5. He was wedged in pretty good, but I don't know if he was causing a short? I flicked him out of there and started the car up and let it idle for 5 minutes or so. Test drive went fine. I dumped a can of sea foam in last night and ran the engine a bit before going to bed. We'll see if it shows up again. Wierd malfunction!

Ha! the bee was a bug in the system? I dont know if bees are conductive.
Glad its working, thats crazy that the tech installed the evap pump upside down.

(p.s. on a 00 up 4.0 L , injector 5 is well behaved, 3 and 4 are usually the bad apples. That debris shield TSB for injectors 3 and 4 has to be BS, i think the shield was engineered to prevent vapor lock. I've never see debris accumulate there.)

yeah, EGR was deleted with the introduction of HO.

92DripCherokee said:

Ha! the bee was a bug in the system? I dont know if bees are conductive.
Glad its working, thats crazy that the tech installed the evap pump upside down.

(p.s. on a 00 up 4.0 L , injector 5 is well behaved, 3 and 4 are usually the bad apples. That debris shield TSB for injectors 3 and 4 has to be BS, i think the shield was engineered to prevent vapor lock. I've never see debris accumulate there.)

yeah, EGR was deleted with the introduction of HO.

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I said the bee was at the fuel rail, I meant the ignition rail.