4 cyl engine issues - JeepForum.com
Reply
 
LinkBack Thread Tools
post #1 of 18 Old 04-05-2010, 02:16 PM Thread Starter
cjapgar
Member
 
cjapgar's Avatar
1994 YJ Wrangler 
 
Join Date: Dec 2008
Location: State College
Posts: 277
4 cyl engine issues

so within the last few days my engine has started running a bit raggedly.
The idle is at about 800, and both idle and neutral rev sound normal.
however when in gear, it is really choppy and i can relate it to the baseball card on a bike tire. Changed the plugs and nothin changed.

Gonna check the ignition coils as soon as i have the time.

what else should i be checking.
to clarify it is only noticeable when in gear.


_______
/l ,[____],
l---L []lllllll[]-
()_)-()_)--o-)_)

Bacon is meat candy!

ΜΟΛΩΝ ΛΑΒΕ!
cjapgar is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 04-05-2010, 02:24 PM
provinT13
Registered User
1999 TJ Wrangler 
 
Join Date: Oct 2007
Location: Colorado Springs
Posts: 4,631
If it's only there when in gear I would start with the transmission, drive shafts, u joints, and t-case

2 Hands Working Do More Than 1000 Hands Praying

94 YJ Build

99 TJ Build
provinT13 is offline  
post #3 of 18 Old 04-05-2010, 02:24 PM
MJMPC
Registered User
1991 YJ Wrangler 
 
Join Date: Nov 2008
Location: Elizabethtown
Posts: 3,064
See if you have any codes showing.

MIKE

http://www.dav.org/

MJM Powder Coating
Elizabethtown Ky.

http://www.cityprofile.com/
MJMPC is offline  
post #4 of 18 Old 04-05-2010, 02:25 PM
RebuildRookie
Registered User
1988 YJ Wrangler 
 
Join Date: Jun 2009
Location: Central Mississippi
Posts: 852
Is that the sound you hear coming from the exhaust or is it a clunking or ticking sound coming from the engine?

I'm a more proactive person.
You spray the ants before they get in your house.
You plant the crops before you starve.
And you keep the terrorists in check before you get your *** blowed off.
RebuildRookie is offline  
post #5 of 18 Old 04-05-2010, 02:28 PM Thread Starter
cjapgar
Member
 
cjapgar's Avatar
1994 YJ Wrangler 
 
Join Date: Dec 2008
Location: State College
Posts: 277
Quote:
Originally Posted by provinT13 View Post
If it's only there when in gear I would start with the transmission, drive shafts, u joints, and t-case
will be checking the tran fluid later, but what all should i be looking for there?

Quote:
Originally Posted by MJMPC View Post
See if you have any codes showing.
no codes but the non-existant ac

Quote:
Originally Posted by RebuildRookie View Post
Is that the sound you hear coming from the exhaust or is it a clunking or ticking sound coming from the engine?
well you can kind of feel it in the pedal, so i dont think its the exhaust, plus checked it out and it looks fine.

so update: checked out the ignition coil : primary was 1.9 high, and the secondary was 12.4 right on would the primary be causing this problem?

_______
/l ,[____],
l---L []lllllll[]-
()_)-()_)--o-)_)

Bacon is meat candy!

ΜΟΛΩΝ ΛΑΒΕ!

Last edited by cjapgar; 04-05-2010 at 09:06 PM. Reason: more info
cjapgar is offline  
post #6 of 18 Old 04-06-2010, 10:37 PM Thread Starter
cjapgar
Member
 
cjapgar's Avatar
1994 YJ Wrangler 
 
Join Date: Dec 2008
Location: State College
Posts: 277
so talked to a car guy and he said the ignition coil is fine, so i picked up wires and a fuel filter. The more i think about it i think its a fuel issue

_______
/l ,[____],
l---L []lllllll[]-
()_)-()_)--o-)_)

Bacon is meat candy!

ΜΟΛΩΝ ΛΑΒΕ!
cjapgar is offline  
post #7 of 18 Old 04-07-2010, 12:29 AM
provinT13
Registered User
1999 TJ Wrangler 
 
Join Date: Oct 2007
Location: Colorado Springs
Posts: 4,631
I really don't see how something making a grinding and chattering noise can be a fuel issue if you're not getting any codes and your engine is running fine in neutral and at idle. Drain/change your trans and t-case fluid. Stick your finger in there and feel around for any metal or gunk that may have gotten in.

2 Hands Working Do More Than 1000 Hands Praying

94 YJ Build

99 TJ Build
provinT13 is offline  
post #8 of 18 Old 04-11-2010, 10:10 PM Thread Starter
cjapgar
Member
 
cjapgar's Avatar
1994 YJ Wrangler 
 
Join Date: Dec 2008
Location: State College
Posts: 277
been diagnosing some more and can say its not the tranny, def either the fuel or ignition

its running real rough, and occasonally back fires, with lots of vibs from non ignited gas or somthing

if i dont get this soon ill have to hit up a shop

_______
/l ,[____],
l---L []lllllll[]-
()_)-()_)--o-)_)

Bacon is meat candy!

ΜΟΛΩΝ ΛΑΒΕ!
cjapgar is offline  
post #9 of 18 Old 04-12-2010, 05:34 AM
EABiker
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2004
Location: Frederick, MD
Posts: 1,719
Grab an ohmmeter and check your sensors; make sure the coolant temp and IAT sensors are reporting the correct air and coolant temps to the ECM. If they are bad, your mixture will be way off and could cause these issues. The IAT should be around1-2K Ohms I believe, and the coolent temp should be under 1K on a warm engine .
EABiker is offline  
post #10 of 18 Old 04-12-2010, 05:08 PM Thread Starter
cjapgar
Member
 
cjapgar's Avatar
1994 YJ Wrangler 
 
Join Date: Dec 2008
Location: State College
Posts: 277
how exactly do you go about testing those, my hanes book says "beyond the scope of the home mechanic"

can i just remove the wiring harness to see if the problem stops? and where exactly are these sensors?

_______
/l ,[____],
l---L []lllllll[]-
()_)-()_)--o-)_)

Bacon is meat candy!

ΜΟΛΩΝ ΛΑΒΕ!
cjapgar is offline  
post #11 of 18 Old 04-12-2010, 06:03 PM Thread Starter
cjapgar
Member
 
cjapgar's Avatar
1994 YJ Wrangler 
 
Join Date: Dec 2008
Location: State College
Posts: 277
was able to check the coolant sensor and cold it read 12 ohms, got dark before i could get to the iat
also tried running it without the iat hooked up and it ran pretty much the same

_______
/l ,[____],
l---L []lllllll[]-
()_)-()_)--o-)_)

Bacon is meat candy!

ΜΟΛΩΝ ΛΑΒΕ!

Last edited by cjapgar; 04-12-2010 at 10:01 PM.
cjapgar is offline  
post #12 of 18 Old 04-16-2010, 10:57 AM Thread Starter
cjapgar
Member
 
cjapgar's Avatar
1994 YJ Wrangler 
 
Join Date: Dec 2008
Location: State College
Posts: 277
Bump...


10char

_______
/l ,[____],
l---L []lllllll[]-
()_)-()_)--o-)_)

Bacon is meat candy!

ΜΟΛΩΝ ΛΑΒΕ!
cjapgar is offline  
post #13 of 18 Old 04-16-2010, 11:09 AM
EABiker
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2004
Location: Frederick, MD
Posts: 1,719
Either of the 2 sensors should measure around 1k-2k (ish), when warmmed up. I installed a 1.2K resistor in the iac harness until the sensor I ordered came in . The engine ran 95% perfect, (which was at least 50% better than before!). My original IAC sensor measured 300K, which said the temp was around -40F !
EABiker is offline  
post #14 of 18 Old 04-16-2010, 11:17 AM
xdgt03
Registered User
1994 YJ Wrangler 
 
Join Date: Feb 2008
Location: a2, mi
Posts: 160
bad crank position sensor, bad map sensor, bad fuel injector

1994 Wrangler YJ
/l ,[____],
l---L--''lllllll''-
()_) ()_)--o-)_)
2.5L
31x10.5x15 BFG MT
xdgt03 is offline  
post #15 of 18 Old 04-16-2010, 11:38 AM
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit
Posts: 21,057
Does it run any different between cold and when its warmed up? Does it happen at idle or when you are accelerating? Backfiring and missing is a timing issue related to sensors. Make sure you read the right temp sensor. The one you want to read is in the front of the engine on the thermostat housing. Clean out your throttle body and your IAC.
Que89YJ is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
4 cyl. engine issues cjapgar YJ Wrangler Technical Forum 16 05-08-2009 09:09 PM
engine issues.. Patriot64 TJ Wrangler Technical Forum 10 04-11-2009 08:33 PM
98 TJ bad engine issues aquaholic_ TJ Wrangler Technical Forum 12 12-07-2008 06:21 PM
89 yj engine issues. Peterkalidonis3 YJ Wrangler Technical Forum 2 10-06-2006 12:53 PM
engine issues JSBlu974X4 TJ Wrangler Technical Forum 4 08-06-2006 06:08 PM

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 On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome