87 yj missing while driving ? HELP?? - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > YJ Jeep Wrangler Forum > YJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 07-07-2009, 01:52 PM   #1
Jeeper
 
Join Date: Jul 2009
Posts: 20
87 yj missing while driving ? HELP??

I have a 87 wrangler 4.2 lit.

While driving the jeep if you get above 50mph it has a miss...not all the time just somtimes...
You will be driving and the rpm will drop fast and shoot right back up.

I replaced the ignition coil, fuel filter, plugs, fuel pump, plug wires, and distributor cap.

Also at idle its only about 600rpm and wont stay idlings by itself. Is their a way to turn the idle up on the stock carb or does anyone have any suggestions to what my problem is...it feels as if its in the carb or in the fuel... thanks

Mike_fx4 is offline   Quote Quick Reply
Old 07-07-2009, 01:55 PM   #2
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
first clean the carb see if that helps and in the mean time the idle adjust is a little screw on the same linkage as the throttle cable i think its the one on the top but i will look at mine later and let u know

morphious is offline   Quote Quick Reply
Old 07-07-2009, 02:06 PM   #3
Jeeper
 
Join Date: Jul 2009
Posts: 20
yeah that would be great if you could do that and let me know forsure where it is. thanks !
Mike_fx4 is offline   Quote Quick Reply
Old 07-07-2009, 02:12 PM   #4
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
ok just ran out and looked at mine and it would appear that i was right now when u go under the hood lok at the side of the cartb were the throtle cable hooks up thats the area u want now theirs going to be three screws u want the top most one their is a trick to tuning idle u dont want it to high it will just burn to much gas but untill u get the other prbs sorted out just take a screw driver and turn it only a quarter turn or less at a time and give it a little gas and see if its idles were u want it hope that helped
morphious is offline   Quote Quick Reply
Old 07-07-2009, 02:23 PM   #5
Jeeper
 
Join Date: Jul 2009
Posts: 20
i done that but it didnt seem to help much...it just wont idle good and its like its not getting enough fuel to the carb or somthing...keeps dropping and coming back up on rpms...
Mike_fx4 is offline   Quote Quick Reply
Old 07-07-2009, 03:17 PM   #6
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
how bad was the fuel filter when u took it off did u blow through it if it was really bad then u might have had debris get into the carb bowl and clogging it all up either do an upgrade on the carb or tear her down and rebuild but its worth the money from what most people say to upgrade sorry i dont have a better answer but i'll keep on it and see what i can come up with we'll figure it out or somebody here will
morphious is offline   Quote Quick Reply
Old 07-07-2009, 03:19 PM   #7
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
hey i just thought of something else it might be their is a second filter inside the tank at least on Chevy's that might be ur issue but i don't know if u want to take a chance on dropping the tank on a hunch though
morphious is offline   Quote Quick Reply
Old 07-07-2009, 03:43 PM   #8
Jeeper
 
87YJWrangler's Avatar
 
Join Date: Sep 2008
Location: Owatonna, Minnesota
Posts: 640
Run a carb cleaner thru your fueltank and see if that helps any, I know it helped my issue I didnt have the miss while driving just when it was idling it would just rumble and sound like hell I ended up running a bottle thru half a tank to make it stronger, I dont advise any less than half a tank but maybe 3/4 tank would be better for yours, whats the miles?
__________________
Mine: 1987 YJ 4.2 5spd soft top
98% of people when they are about to go into the ditch say "oh shit!" The other 2% are Minnesotans and when we are about to go into a ditch we say "Hold my beer and watch this shit!"
87YJWrangler is offline   Quote Quick Reply
Old 07-07-2009, 04:07 PM   #9
Jeeper
 
Join Date: Jul 2009
Posts: 20
it has 147,000 miles on it.
Mike_fx4 is offline   Quote Quick Reply
Old 07-07-2009, 05:00 PM   #10
Jeeper
 
Join Date: Jul 2009
Posts: 20
I put some carb treatment in the fuel....i have drove it.....

When i go to slow down it just wants to choke out and die.....and when i just flat foot it, it spits and sputters.... ??? i just dont know...
Mike_fx4 is offline   Quote Quick Reply
Old 07-07-2009, 06:39 PM   #11
Jeeper

WF Supporting Member
 
copleydad's Avatar
 
Join Date: Jun 2009
Location: Woburn MA
Posts: 368
I had a similar problem. It turned out to be a bad EGR valve. Replaced it and it ran like new
__________________
GRACIE

1989 Wrangler "Islander" 4.2 6cyl 5 speed

copleydad is offline   Quote Quick Reply
Old 07-07-2009, 06:41 PM   #12
Jeeper
 
Join Date: Jul 2009
Posts: 20
what was the symtoms of yours ......where is that egr valve located and how much did it run you.
Mike_fx4 is offline   Quote Quick Reply
Old 07-07-2009, 06:50 PM   #13
Jeeper

WF Supporting Member
 
copleydad's Avatar
 
Join Date: Jun 2009
Location: Woburn MA
Posts: 368
It would sit and idle like a wheezing great grandma, sputter and die without pumping the pedal. Would get up to speed and felt like it wanted to shut off and would cough and sputter.

One thing I remember is the strong gas smell when I would be warming it up. The EGR (exhaust gas recycler) is a diaphragm with a rod that opens and closes the diaphragm located under the carb.

If it is locked up, it pretty much just purs raw gas into the carb and exhaust giving you really bad mileage and an engine that runs like crap.

The part was about $80 or $90 if I remember correctly, and it took about 20 minutes to change. I knew mine was bad because it was kinda flopping around, brackets rusted away sitting at the beach in the Outer Banks

Good luck
__________________
GRACIE

1989 Wrangler "Islander" 4.2 6cyl 5 speed

copleydad is offline   Quote Quick Reply
Old 07-07-2009, 06:54 PM   #14
Jeeper
 
Join Date: Jul 2009
Posts: 20
Sounds great...thanks !
Mike_fx4 is offline   Quote Quick Reply
Old 07-07-2009, 07:00 PM   #15
Jeeper
 
Join Date: Jul 2009
Posts: 20
Is it located under the carb, bolted on the side of the intake with a vacum hose running from it ?
Mike_fx4 is offline   Quote Quick Reply
Old 07-08-2009, 04:11 PM   #16
Jeeper

WF Supporting Member
 
copleydad's Avatar
 
Join Date: Jun 2009
Location: Woburn MA
Posts: 368
Yup. It's this thing.
Attached Images
 
__________________
GRACIE

1989 Wrangler "Islander" 4.2 6cyl 5 speed

copleydad is offline   Quote Quick Reply
Old 07-08-2009, 10:39 PM   #17
Jeeper
 
buckshot500's Avatar
 
Join Date: Mar 2009
Location: Carolina
Posts: 798
Quote:
Originally Posted by copleydad View Post
I had a similar problem. It turned out to be a bad EGR valve. Replaced it and it ran like new
X2 on this, since I did the Nutter I just plugged the vacuum line after pulling it off the EGR

Another thing is the fuel filter orientation.

It has three connections. The small one (return to tank) must be at the
12 O'clock position. The carb end (outlet) of the fuel filter should be slightly uphill from the fuel pump end (inlet). Or at least level.
__________________
90YJ 98XJ
buckshot500 is offline   Quote Quick Reply
Old 07-08-2009, 11:07 PM   #18
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
wow i feel dumb for not thinking of that
__________________
some say why i say
its a jeep thing u wouldn't understand
morphious is offline   Quote Quick Reply
Old 07-09-2009, 03:17 PM   #19
Jeeper
 
Join Date: Jul 2009
Posts: 20
well here is the deal.... i had my carb cleaned and checked today and said it was ok....it drove so much better and and idled better.....but still feels weak, and still have that bad miss to it while driving over 60 and if i push the gas hard coming from a dead stop..and i can smell fuel ? what do you think.....maybe egr valve or what ??
Mike_fx4 is offline   Quote Quick Reply
Old 07-09-2009, 06:30 PM   #20
Jeeper
 
buckshot500's Avatar
 
Join Date: Mar 2009
Location: Carolina
Posts: 798
Quote:
Originally Posted by Mike_fx4 View Post
well here is the deal.... i had my carb cleaned and checked today and said it was ok....it drove so much better and and idled better.....but still feels weak, and still have that bad miss to it while driving over 60 and if i push the gas hard coming from a dead stop..and i can smell fuel ? what do you think.....maybe egr valve or what ??
Pull the hose off the EGR, & plug it with a small screw or bolt.

If it clears right up, then you have found the culprit!

Now you just have to decide if the plug will do, or you want your wallet to be $80.00 lighter.

If your going 60 mph & it suddenly feels like your fuel line is sucking air, (enough to shift your upper body off the seat back) then it's exactly like mine was.....EGR!
__________________
90YJ 98XJ
buckshot500 is offline   Quote Quick Reply
Old 07-09-2009, 08:28 PM   #21
Jeeper
 
Join Date: Jul 2009
Posts: 20
so all you done was plug that one vacum line off of the egr and left a screw in it and that solved your problem ? thats awesome if it works ! thanks
Mike_fx4 is offline   Quote Quick Reply
Old 07-11-2009, 10:03 PM   #22
Jeeper
 
Join Date: Jul 2009
Posts: 20
heres the deal.... i have checked the egr by unplugging it and stoping the vacum up...that didnt work....i took it fourwheelin today, it has drove fine untill about 25 miles down the road after it got warm it started missing really bad...but doesnt do it when its cold, just when it starts warming up its got a horrible miss to it. im so puzzled
Mike_fx4 is offline   Quote Quick Reply
Old 07-12-2009, 10:44 AM   #23
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
almost sounds like a electrical problem to me like once something gets hot it starts to shut down or break down when u changed the coil did u replace everything i know i had a Chevy that did something like this replaced the condenser with the coil and fixed it
__________________
some say why i say
its a jeep thing u wouldn't understand
morphious is offline   Quote Quick Reply
Old 07-12-2009, 01:34 PM   #24
Jeeper
 
Join Date: Jul 2009
Posts: 20
No i just replaced the coil its self... it sounds like somthing electrical to me also.. cause soon as it gets hot it starts breaking down...the farther i drive it the worse it gets till cools down.
Mike_fx4 is offline   Quote Quick Reply
Old 07-12-2009, 01:43 PM   #25
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
id check and make sure that theirs not a condenser on their not sure if their is and its raining here so not going to go look at mine but if their is then that is were i would put my money on either that or something in the ignition controll box
__________________
some say why i say
its a jeep thing u wouldn't understand
morphious is offline   Quote Quick Reply
Old 07-12-2009, 02:37 PM   #26
Jeeper
 
Join Date: Jul 2009
Posts: 20
where is the ignition control box located... i got a new rotor button and some wires im going to re wire everything and put that button on and see if that helps anything
Mike_fx4 is offline   Quote Quick Reply
Old 07-12-2009, 08:11 PM   #27
Jeeper
 
Join Date: Jul 2009
Posts: 20
well i ran new wires on to the coil and put a new rotor button on and its still missing ...never going to figure this out.
Mike_fx4 is offline   Quote Quick Reply
Old 07-13-2009, 05:15 AM   #28
Jeeper
 
buckshot500's Avatar
 
Join Date: Mar 2009
Location: Carolina
Posts: 798
Quote:
Originally Posted by Mike_fx4 View Post
so all you done was plug that one vacum line off of the egr and left a screw in it and that solved your problem ? thats awesome if it works ! thanks
Quote:
Originally Posted by Mike_fx4 View Post
heres the deal.... i have checked the egr by unplugging it and stoping the vacum up...that didnt work...
It worked for me, because I apparently had a bad EGR.

At least you now know your problem isn't the EGR.

It does sound carb related, do you still run the stock Carter BBD?

You might want to look into an "MC2100" swap. It's A junkyard carb that you rebuild yourself. (very easy)

Of course you want to locate the true cause of this problem, before dropping any cash unless you were going to do it anyway.
__________________
90YJ 98XJ
buckshot500 is offline   Quote Quick Reply
Old 07-13-2009, 09:52 AM   #29
after birthday glow
 
morphious's Avatar
 
Join Date: Jul 2009
Location: wisconsin
Posts: 1,963
Images: 1
i checked my coil and didn't find a condenser so that shouldn't be a prob so does anyone know if this could be a vacuum prob i'm running out of ideas on this one
__________________
some say why i say
its a jeep thing u wouldn't understand
morphious is offline   Quote Quick Reply
Old 07-13-2009, 05:34 PM   #30
Jeeper
 
Join Date: Jul 2009
Posts: 20
its a rough one...i got to thinking..i bought a rebuild kit for the carb, took it to this guy to rebuild it, he called and said it didnt need the kit everything looked good. but he didnt even take it off the motor so how could he have known that everything looked good. its 22yrs old....so i believe the carb needs rebuilt.....what do you think ?

Mike_fx4 is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Unknown missing parts Hank TJ Tech Forum 22 06-03-2009 01:33 AM
Crappy driving light stem CenARJeepChick TJ General Discussion Forum 1 03-09-2009 03:32 PM
Interstate driving question about snow and ice scotiez General Jeep Discussion 16 03-13-2008 09:01 PM
Irratic idle and hestitation while driving jeeper95yj YJ Tech Forum 5 02-24-2008 12:54 PM
if you have 4 Hella 500 lights. 2 are the driving lights and 2 are the fogs lights wh jjock TJ General Discussion Forum 2 12-05-2006 09:15 PM



» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 06:43 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC