Running rough, code 27, exhaust smells like unburnt fuel - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > Running rough, code 27, exhaust smells like unburnt fuel

FS: Wrangler RGB Multicolor Fog Light LEDs: Awesome EffectThanksgiving holiday sale in effect @ oconeeoffroad.comRugged Ridge 8500lb Winch w/ Steel Cable $294.99 Shipped O

Reply
Unread 05-20-2013, 05:53 PM   #1
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
Running rough, code 27, exhaust smells like unburnt fuel

Stands to reason that the day after I get home for the summer, the Jeep would crap out on me. I was cruising along in 4th gear yesterday and I noticed it was running kind of rough. It got progressively worse, to the point where it obviously wasn't running on all cylinders. I can feel a slap in the exhaust, and the exhaust reeks of unburnt fuel. Checked for codes, originally got 27 and 11. Here's what I have done so far:

Cleared the codes, problem persists, code 27 came back, 11 did not
(For reference, the O2 sensor is < 6 months old)

Went around pulling the plugs off the injectors to try and isolate the cylinder. Cylinder 1 is the only cylinder that when I pull the injector plug off, the engine doesn't seem to change.

Checked spark, seems weak, yellow instead of whitish/blue

Plugged a spare injector into #1's plug, and I can feel the injector pulsing. So #1 is obviously getting electricity and at least some sort of signal.

Here's some of my ruminations so far. If the problem was solely with #1 injector, shouldn't the fuel smell go away when I pull the injector plug off? Because it didn't. I went around pulling all the injector plugs checking 1x1 for the smell to be gone but it never was. The problem gets progressively worse. When I first started testing today it wasn't that bad, but after about 30 minutes of running on and off it could barely maintain an idle, and stalled out several times. Spark is consistently weak on all of the cylinders, unless maybe the sparks only supposed to be a yellow? I was always told whitish/blue. Maybe the injector is stuck open? I haven't tried actually switching the injector yet, maybe I should try that. I've also read that it can be a bad ECM. Which I really hope its not.

Anyways, I have a headache from the fuel smell, so I'm stopping my testing for now. If you have any ideas please let me know I hate having nice weather and not being able to drive the Jeep.

nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-20-2013, 06:28 PM   #2
idaholtby
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2008
Location: Meridian, Idaho
Posts: 2,554
Well, code #27 is the concern. Code#11 is as well, but she is running otherwise. Could be a bad cpk sensor in the dizzy as the cause, but with #27, I would first check all the injectors with an Ohm meter and see if they all agree, or rather read the same. Unplug all injectors and read across the injector terminals with a meter and write down the values for each one. If one is out of the norm, then replace it. If all injectors read the same resistive value, then I would suspect the pick up sensor in the distributer as to the cause.
idaholtby is offline   Reply With Quote Quick reply to this message
Unread 05-21-2013, 06:40 PM   #3
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
Quote:
Originally Posted by idaholtby View Post
Well, code #27 is the concern. Code#11 is as well, but she is running otherwise. Could be a bad cpk sensor in the dizzy as the cause, but with #27, I would first check all the injectors with an Ohm meter and see if they all agree, or rather read the same. Unplug all injectors and read across the injector terminals with a meter and write down the values for each one. If one is out of the norm, then replace it. If all injectors read the same resistive value, then I would suspect the pick up sensor in the distributer as to the cause.
All the injector readings come in at around 14.4. I guess I'll try and see if there's a way to test the distributor pick up sensor
nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-21-2013, 08:45 PM   #4
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801


I think I found the problem
nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 07:31 AM   #5
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,608
Cant see pics at work Nathtan, what was it?
Que89YJ is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 07:44 AM   #6
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
The wires on the oxygen sensor are completely ripped off
nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 11:06 AM   #7
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,608
lol yep that will do it.
Que89YJ is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 01:49 PM   #8
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
Well I put the new sensor in, started her up and she ran for a minute or so and then stalled. Now she won't stay running for more than a few seconds, if I can even get her started
nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 02:21 PM   #9
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
Well got her started, added some gas and let her sit. Got the engine up to operating temperature and still running rough and throwing code 27. And still dumping fuel out the exhaust. Codes have been cleared but they just come back. I unplugged the oxygen sensor while it was running and it made no change. I'm thinking maybe something with the wiring of the oxygen sensor is wrong. I'm getting frustrated though
nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 02:46 PM   #10
tdewit
Registered User
1991 YJ Wrangler 
 
Join Date: Sep 2006
Location: Ohio
Posts: 533
Code 27: INJECTOR #1-6 CONTROL CIRCUIT. Condition is: injector output driver does not respond properly to Powertrain Control Module (PCM) control signal.

TEST FC-19A - INJECTOR #1 CONTROL CIRCUIT
NOTE: For connector terminal identification, see CONNECTOR
IDENTIFICATION at beginning of article. For wiring diagrams,
see L - WIRING DIAGRAMS article in the ENGINE PERFORMANCE
Section.
1) Using DRB-II, erase fault messages. Attempt to start
engine. If engine will not start, crank engine for at least 10
seconds.
2) Using DRB-II, read fault messages. If engine started,
allow engine to idle for at least 20 seconds. If DRB-II does not
display INJECTOR #1 CONTROL CIRCUIT, condition required to set fault
is not present at this time. Go to next step. If DRB-II displays
INJECTOR #1 CONTROL CIRCUIT, go to step 6).
3) INJECTOR #1 CONTROL CIRCUIT fault sets if Powertrain
Control Module (PCM) does not detect injector "turn off edge" when
expected. Possible causes are: open or shorted injector ground circuit
(White/Dark Blue wire), open injector power supply circuit (Dark
Green/Orange wire on XJ and YJ bodies or Dark Green/Black wire on ZJ
body), open injector, or failed driver in Powertrain Control Module
(PCM). Go to next step.
4) Inspect all related wiring and connectors and repair as
necessary. Perform TEST VER-1. If no problems were found with wiring
and connectors, go to next step.
5) Start engine. Wiggle wiring harness from injector No. 1 to
Powertrain Control Module (PCM). If engine misfires or stalls, repair
wiring harness as necessary. Perform TEST VER-1. If engine does not
misfire or stall, see INACTIVE FAULT CONDITION. Perform TEST VER-1.
6) Turn ignition off. Disconnect injector No. 1 connector.
Using an external ohmmeter, check resistance of injector No. 1. If
resistance is not 10-16 ohms, replace injector. Perform TEST VER-1. If
resistance is 10-16 ohms, turn ignition on. Using DRB-II, actuate
injector No. 1.
7) Using DRB-II in voltmeter mode, check voltage on injector
connector (harness side) Dark Green/Orange wire on XJ and YJ bodies or
Dark Green/Black wire on ZJ body. If voltage is less than 10 volts,
repair open in Dark Green/Orange wire on XJ and YJ bodies or Dark
Green/Black wire on ZJ body. Perform TEST VER-1.
8) If voltage is more than 10 volts, turn ignition off.
Disconnect Powertrain Control Module (PCM) connector. Using an
external ohmmeter, check resistance of injector driver circuit
(White/Dark Blue wire), between PCM connector terminal No. 16 and
injector connector. If resistance is less than 5 ohms, go to next
step. If resistance is more than 5 ohms, repair open in White/Dark
Blue wire. Perform TEST VER-1.
9) Using DRB-II in ohmmeter mode, check resistance of PCM
connector terminal No. 16, injector driver circuit (White/Dark Blue
wire). If resistance is less than 5 ohms, repair short to ground in
White/Dark Blue wire. Perform TEST VER-1. If resistance is more than 5
ohms, replace PCM. Perform TEST VER-1.
tdewit is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 04:09 PM   #11
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
Quote:
Originally Posted by tdewit View Post
Code 27: INJECTOR #1-6 CONTROL CIRCUIT. Condition is: injector output driver does not respond properly to Powertrain Control Module (PCM) control signal.

TEST FC-19A - INJECTOR #1 CONTROL CIRCUIT
NOTE: For connector terminal identification, see CONNECTOR
IDENTIFICATION at beginning of article. For wiring diagrams,
see L - WIRING DIAGRAMS article in the ENGINE PERFORMANCE
Section.
1) Using DRB-II, erase fault messages. Attempt to start
engine. If engine will not start, crank engine for at least 10
seconds.
2) Using DRB-II, read fault messages. If engine started,
allow engine to idle for at least 20 seconds. If DRB-II does not
display INJECTOR #1 CONTROL CIRCUIT, condition required to set fault
is not present at this time. Go to next step. If DRB-II displays
INJECTOR #1 CONTROL CIRCUIT, go to step 6).
3) INJECTOR #1 CONTROL CIRCUIT fault sets if Powertrain
Control Module (PCM) does not detect injector "turn off edge" when
expected. Possible causes are: open or shorted injector ground circuit
(White/Dark Blue wire), open injector power supply circuit (Dark
Green/Orange wire on XJ and YJ bodies or Dark Green/Black wire on ZJ
body), open injector, or failed driver in Powertrain Control Module
(PCM). Go to next step.
4) Inspect all related wiring and connectors and repair as
necessary. Perform TEST VER-1. If no problems were found with wiring
and connectors, go to next step.
5) Start engine. Wiggle wiring harness from injector No. 1 to
Powertrain Control Module (PCM). If engine misfires or stalls, repair
wiring harness as necessary. Perform TEST VER-1. If engine does not
misfire or stall, see INACTIVE FAULT CONDITION. Perform TEST VER-1.
6) Turn ignition off. Disconnect injector No. 1 connector.
Using an external ohmmeter, check resistance of injector No. 1. If
resistance is not 10-16 ohms, replace injector. Perform TEST VER-1. If
resistance is 10-16 ohms, turn ignition on. Using DRB-II, actuate
injector No. 1.
7) Using DRB-II in voltmeter mode, check voltage on injector
connector (harness side) Dark Green/Orange wire on XJ and YJ bodies or
Dark Green/Black wire on ZJ body. If voltage is less than 10 volts,
repair open in Dark Green/Orange wire on XJ and YJ bodies or Dark
Green/Black wire on ZJ body. Perform TEST VER-1.
8) If voltage is more than 10 volts, turn ignition off.
Disconnect Powertrain Control Module (PCM) connector. Using an
external ohmmeter, check resistance of injector driver circuit
(White/Dark Blue wire), between PCM connector terminal No. 16 and
injector connector. If resistance is less than 5 ohms, go to next
step. If resistance is more than 5 ohms, repair open in White/Dark
Blue wire. Perform TEST VER-1.
9) Using DRB-II in ohmmeter mode, check resistance of PCM
connector terminal No. 16, injector driver circuit (White/Dark Blue
wire). If resistance is less than 5 ohms, repair short to ground in
White/Dark Blue wire. Perform TEST VER-1. If resistance is more than 5
ohms, replace PCM. Perform TEST VER-1.
Well if I did this right, I need to replace my pcm. But I can't just drop $200 at the drop of a hat, plus I'm not even sure I did the test right. It's very confusing, plus what is TEST VER-1? And I'm assuming DRB-II is some sort of tester? Here's my results

All injectors come in at around 14 ohms.

Tested voltage on injector harness, but did they want me to test it against a ground or against the other wire or against the positive terminal in the battery or what? I tested it against a ground and got roughly 13 volts.

Checked resistance between pcm pin 16 and injector connector and got 0 ohms.

And then check resistance of pcm pin 16....Again, against what? I checked it against ground and got infinity ohms.
nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 04:23 PM   #12
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,608
its not the pcm. did you disconnect the battery after replacing the sensor?
Que89YJ is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 04:35 PM   #13
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
Quote:
Originally Posted by Que89YJ View Post
its not the pcm. did you disconnect the battery after replacing the sensor?
Yup disconnected and turned the lights on to clear any residual charge out. Still running rough and dumping fuel. And that pesky code 27 comes back every time.

EDIT: Messing around with it some more and now I've got a code 11 as well
nathanninja is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 07:44 PM   #14
idaholtby
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2008
Location: Meridian, Idaho
Posts: 2,554
Quote:
Originally Posted by nathanninja View Post
Yup disconnected and turned the lights on to clear any residual charge out. Still running rough and dumping fuel. And that pesky code 27 comes back every time.

EDIT: Messing around with it some more and now I've got a code 11 as well
Must be the pick up sensor in the distributer. This sensor helps to sync the injector pulses. This would explain the remainder of your issues. I would recommend replacing the entire distributer with a rebuilt unit. If this sensor went sour, chances are the rest of the distributer, mainly the shaft bushing is bad or will be soon. It is possible to just replace the sensor, but a rebuilt dizzy from NAPA with the new sensor installed cost $89 the last time I replaced mine. Plus... Thanks Que for keeping on top of this thread. I've been tied up, but the 16yr-old's Cherokee is finally on the road and is as good as new!
idaholtby is offline   Reply With Quote Quick reply to this message
Unread 05-22-2013, 10:40 PM   #15
nathanninja
Registered User
1991 YJ Wrangler 
 
Join Date: Apr 2011
Location: Collegeville, Pennsylvania
Posts: 801
Quote:
Originally Posted by idaholtby View Post

Must be the pick up sensor in the distributer. This sensor helps to sync the injector pulses. This would explain the remainder of your issues. I would recommend replacing the entire distributer with a rebuilt unit. If this sensor went sour, chances are the rest of the distributer, mainly the shaft bushing is bad or will be soon. It is possible to just replace the sensor, but a rebuilt dizzy from NAPA with the new sensor installed cost $89 the last time I replaced mine. Plus... Thanks Que for keeping on top of this thread. I've been tied up, but the 16yr-old's Cherokee is finally on the road and is as good as new!
I actually have a spare distributer from my old engine. With sensor intact. Think it's worth swapping that in to see if it fixed anything? It's free at least. Here's some pictures of it, looks perfectly fine, and I had no issues with it in the old engine. But pictures mainly because I'm in love with my Galaxy s3


nathanninja is offline   Reply With Quote Quick reply to this message
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.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
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






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.