help with misfire on 2000
#1
Member
Thread Starter
Join Date: Dec 2009
Location: Wilmington, NC
Posts: 247
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0
help with misfire on 2000
heres the deal, ive posted this in my build thread but figured id get better response here. i just recently put a clearwater head on my 2000 which had a cracked head. got a few codes ofcourse on start up, all cleared but cylinder 5 misfire. it seemed to get a little better the more i drove it around the neighborhood and would idle fine/run on all 6 cylinders for a while, then it was intermittent. i decided to put some fuel injector cleaner in it when i drove it up the road to put gas in it... now this
did a little troubleshooting and im stumped.
cylinder 5 is not firing at all, or should i say not working b/c its got spark to the spark plug from the coil, voltage on the injector plug and the injector ohms fine.
checked injector wire voltage and it appears to be on par with all the others, checked the injectors resistance and it read about 13 ohms (including .5-.8 lead resistance) which was also what the other injectors read. also swapped the plugs around and still nothing on 5 (i can take the injector wire off 5 and it idles the same but if i remove the others it idles even worse so i know its isolated to cylinder 5 and the code confirms it)
so i figure its getting power to the injector, so i pulled the coil pack off (damn distributor-less crap), stuck a spark plug in cylinder 5 boot and ran a piece of wire from the electrode of the plug to ground, turned it over and got spark...
dirty/clogged injector perhaps? its all i can think of since its got worse since i put fuel injector cleaner in it
did a little troubleshooting and im stumped.
cylinder 5 is not firing at all, or should i say not working b/c its got spark to the spark plug from the coil, voltage on the injector plug and the injector ohms fine.
checked injector wire voltage and it appears to be on par with all the others, checked the injectors resistance and it read about 13 ohms (including .5-.8 lead resistance) which was also what the other injectors read. also swapped the plugs around and still nothing on 5 (i can take the injector wire off 5 and it idles the same but if i remove the others it idles even worse so i know its isolated to cylinder 5 and the code confirms it)
so i figure its getting power to the injector, so i pulled the coil pack off (damn distributor-less crap), stuck a spark plug in cylinder 5 boot and ran a piece of wire from the electrode of the plug to ground, turned it over and got spark...
dirty/clogged injector perhaps? its all i can think of since its got worse since i put fuel injector cleaner in it
#2
CF Veteran
Join Date: Sep 2010
Location: Salt Lake City, UT
Posts: 4,968
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0L
Sounds like it to me.. swap it to cyl 1 (easiest to replace later) if it moves to cyl 1 its the injector... Then get a new one(napa sold me one for 50$?) Was your fuel rail full of poo looking rust? lol They like to clog up as its a returnless sysetem and can plug injectors... #5-6 are the most common as it pushes to the back of the rail.
#3
Member
Thread Starter
Join Date: Dec 2009
Location: Wilmington, NC
Posts: 247
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0
Sounds like it to me.. swap it to cyl 1 (easiest to replace later) if it moves to cyl 1 its the injector... Then get a new one(napa sold me one for 50$?) Was your fuel rail full of poo looking rust? lol They like to clog up as its a returnless sysetem and can plug injectors... #5-6 are the most common as it pushes to the back of the rail.
ill try that. thanks!
#4
CF Veteran
Join Date: Sep 2010
Location: Salt Lake City, UT
Posts: 4,968
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0L
Thread
Thread Starter
Forum
Replies
Last Post
john,k
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
4
09-27-2015 10:19 PM
evguy
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
14
09-27-2015 10:58 AM
02809bristol
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
09-26-2015 12:02 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)