XJ: miss fire every once and awhile on start up - Great Lakes 4x4. The largest offroad forum in the Midwest

Go Back   Great Lakes 4x4. The largest offroad forum in the Midwest > 4x4 Talk > Jeep Tech
GL4x4 Live! GL4x4 Casino

greatlakes4x4.com is the premier Great Lakes 4x4 Forum on the internet. Registered Users do not see the above ads.
Search
Reply
 
Thread Tools Search this Thread
Old October 9th, 2013, 09:12 PM   #1
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default miss fire every once and awhile on start up

i have a 2000 xj with a 4.0 only thin aftermarket done to the motor is a throttle body spacer and i had the missfire before i installed that it only happens once and awhile on start up and if u rev it it goes away im hopeing it doesnt have anything to do with the direct igntion
2000xjforlife is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old October 9th, 2013, 09:16 PM   #2
firehawk
Live Action!
 
firehawk's Avatar
 
Join Date: 10-02-07
Location: Clawson, Michigan
Posts: 12,542
iTrader: (44)
Mentioned: 13 Post(s)
Default

Ever give her a tune up?


Plugs, wires, fuel injector cleaner..........?
firehawk is offline   Reply With Quote
Old October 9th, 2013, 09:44 PM   #3
jaysusr
Senior Member
 
jaysusr's Avatar
 
Join Date: 03-29-10
Location: Oakland county.
Posts: 1,055
iTrader: (2)
Mentioned: 0 Post(s)
Default

This is coil on plug I believe, tune up x2...
jaysusr is offline   Reply With Quote
Old October 9th, 2013, 10:27 PM   #4
Toyfish
Senior Member
 
Toyfish's Avatar
 
Join Date: 02-05-10
Location: lapeer, MI
Posts: 2,206
iTrader: (32)
Mentioned: 9 Post(s)
Default

My tj did the same thing it was worse when warm. Mine just stopped doing it on its own so i guess im no help here

Sent from my DROID X2 using Tapatalk 2
Toyfish is offline   Reply With Quote
Old October 10th, 2013, 07:02 PM   #5
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

ive gave it a tune up wich just consist of new plugs correct since its direct igntion theres no wires unless it consist of these boots i just found on azs website i mean i keep up on maintenance ad u run lucas injector cleaner atleast once a month
2000xjforlife is offline   Reply With Quote
Old October 10th, 2013, 07:04 PM   #6
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

ya its coil on plug has one long bar with all of them in one i just found u can buy these boots and new springs for the coils think i might try that
2000xjforlife is offline   Reply With Quote
Old October 10th, 2013, 07:09 PM   #7
Dylan
Senior Member
 
Dylan's Avatar
 
Join Date: 08-24-06
Location: K-zoo
Posts: 1,125
iTrader: (7)
Mentioned: 0 Post(s)
Default

Those coil packs can develop cracks and cause a miss. I have gone though a few of them (OEM and aftermarket) They are starting to stock the replacement ones at the local parts stores because they brake that much.

You can do a buy online from Advance Auto and use promo code trt30 for 30% off. Its a lifetime warranty also.
Dylan is online now   Reply With Quote
Old October 10th, 2013, 07:57 PM   #8
GREASYHANDS
PICKLES!!!!
 
GREASYHANDS's Avatar
 
Join Date: 03-16-09
Location: Ravenna
Posts: 13,301
iTrader: (28)
Mentioned: 25 Post(s)
Default

Cracked head
__________________
Bare Bones Offroad
RIP FS4L
Pavement sucks
Meow
GREASYHANDS is offline   Reply With Quote
Old October 12th, 2013, 09:22 PM   #9
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

ya ill have to replace that and ya its not a cracked head lmao
2000xjforlife is offline   Reply With Quote
Old October 13th, 2013, 10:37 PM   #10
JEFF
Hold my beer!!
 
JEFF's Avatar
 
Join Date: 03-01-06
Location: Hamburg
Posts: 962
iTrader: (7)
Mentioned: 0 Post(s)
Default

Do know what cylinder is misfiring? Most common is #3 cylinder misfire, there was a TSB released which more or less consisted of a corigated cardboard tube that got zip tied around the #3 fuel injector to shield it from heat. The few that I have done corrected it misfire issue.
JEFF is offline   Reply With Quote
Old October 14th, 2013, 08:33 PM   #11
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

no i dont know wich one is missfireing all i know is it missfires once and awhile on start up never when its hot or when im rageing on it or wheeling or anything like that
it only does it when its cold
2000xjforlife is offline   Reply With Quote
Old October 14th, 2013, 08:35 PM   #12
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

well i have to correct my self it has done it when it was hot like the other day i drove it all the way to work wich is like 50 miles never missfired one time got to work parked and like 5 mins later i had to move it started it up and it missfired and i had to rev it up to get it to stop
2000xjforlife is offline   Reply With Quote
Old October 15th, 2013, 11:22 AM   #13
Punisher115
Newbie
 
Punisher115's Avatar
 
Join Date: 11-03-08
Location: Clarkston, MI
Posts: 14
iTrader: (1)
Mentioned: 0 Post(s)
Send a message via AIM to Punisher115 Send a message via Yahoo to Punisher115
Default

I have the same problem on my 01XJ. I have replaced most of the components you would think we be a problem and it continues.

I found a thread on a XJ forum a while back that said it is a problem with the check ball in the fuel pump assembly that fails and lets the fuel pressure drop in the feed line. Instead of having fuel pressure at the rail on startup, the pump is still trying to prime the fuel system and causes the misfire due to lean/fuel starve conditions. The advice was to replace the unit, or key the jeep on and off a few time to prime.

I key mine on 3 times and no misfires.... occasionally it will do it, but not like it used to.

Hopefully that helps... I would at least try that and see if it continues. Other than bit of advice, I have no idea..., but it's working on my Jeep.
Punisher115 is offline   Reply With Quote
Old October 15th, 2013, 04:26 PM   #14
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

ill try that cause ya it did it today i drove to the dealer wich is 10 mins away shut it off for like 5 mins go back out start it up and bam it was missfireing and had to rev it up acouple times and it went away
2000xjforlife is offline   Reply With Quote
Old October 15th, 2013, 09:24 PM   #15
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

where would i get that part your are speaking off Jeff that goes around #3 fuel injector im try all cheapest to most expensive
2000xjforlife is offline   Reply With Quote
Old October 15th, 2013, 09:46 PM   #16
Toivo
Feel lucky?
 
Toivo's Avatar
 
Join Date: 02-24-06
Location: Denver
Posts: 5,147
iTrader: (13)
Mentioned: 0 Post(s)
Default

Like punisher said, Jeeps are notorious for the in tank fuel pressure back flow preventer aka check ball for failing. This causes long crank on some and could cause your concern. Check fuel pressure key on cold and see if it has to build a lot of pressure. Or just replace parts, your call. Diagnosis is for dummies anyways
Toivo is offline   Reply With Quote
Old October 16th, 2013, 08:56 AM   #17
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

Quote:
Originally Posted by Toivo View Post
Like punisher said, Jeeps are notorious for the in tank fuel pressure back flow preventer aka check ball for failing. This causes long crank on some and could cause your concern. Check fuel pressure key on cold and see if it has to build a lot of pressure. Or just replace parts, your call. Diagnosis is for dummies anyways
umm ok
2000xjforlife is offline   Reply With Quote
Old October 16th, 2013, 01:33 PM   #18
JeepInABox
Jeep yard art collector.
 
JeepInABox's Avatar
 
Join Date: 10-25-07
Location: Fenton
Posts: 2,322
iTrader: (8)
Mentioned: 0 Post(s)
Default

I have seen the check valve go bad and the fuel rail lose pressure in seconds after shut off. Put a pressure gauge on it and run it till it stops missing, then turn it off and watch the gauge, check In 1, 5, 10, 30, 60 minutes should not drop more then 10% in 24 hours
JeepInABox is offline   Reply With Quote
Old October 19th, 2013, 10:21 PM   #19
JEFF
Hold my beer!!
 
JEFF's Avatar
 
Join Date: 03-01-06
Location: Hamburg
Posts: 962
iTrader: (7)
Mentioned: 0 Post(s)
Default

Quote:
Originally Posted by 2000xjforlife View Post
where would i get that part your are speaking off Jeff that goes around #3 fuel injector im try all cheapest to most expensive
Local dealer, there is a service bulletin out for this problem. The way the newer style manifolds are designed it directs the heat at the #3 injector. However both my 01 and 96 XJ's will run rough when I am working them or it is hot outside......even with the injector insulated. I would lean away from the fuel pump check valve being the fact that if the check valve had failed and would bleed off pressure, this would also cause a long crank time on first start up (like ten seconds plus) cant hurt to check it anyway if you have a fuel pressure gauge.
JEFF is offline   Reply With Quote
Old October 21st, 2013, 07:46 PM   #20
2000xjforlife
Senior Member
 
2000xjforlife's Avatar
 
Join Date: 12-20-12
Location: fenton michigan
Posts: 165
iTrader: (1)
Mentioned: 0 Post(s)
Default

ya it always starts right up but i got a update on this i do belave it is the fuel pump cause last night i went offroading in my friends man made off road park and my jeep got stuck on a hill where the back of my jeep was way in the air and the front end was buried was at least a 45 deg angle at least it was running fine when i turn it off to go get the tractor to pull me out and when i got in my jeep to start it it would not start at all just turned over and over again i actually had to get in the gas to get it to start and when it started it misfired bad and barely wanted to run then i had to rev it like 4 times and then it was running fine but my buddy was like oo classic jeep stuck on a hill its not getting gas lol but i really thought about what Ive heard on here from everyone makes me really think it is the fuel pump what u all think?
2000xjforlife is offline   Reply With Quote
Reply
Great Lakes 4x4. The largest offroad forum in the Midwest > 4x4 Talk > Jeep Tech

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 11:04 PM.


Powered by: vBulletin, Copyright 2000 - 2012, Jelsoft Enterprises Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
Page generated in 0.26380 seconds with 81 queries