Need Help Really Confused - JeepForum.com
 
LinkBack Thread Tools
post #1 of 14 Old 06-20-2010, 02:47 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Need Help Really Confused

99 wj 4.7
I keep getting a check engine light on for p1391, I have replaced both the cam and crank sensors. I have even replaced the tps to see if that would work but the jeep still puts out a check engine light. Along with the check engine light on the jeep is missing or studdering when I floor it. I am really confused to what could be causing the jeep to have this problem. The jeep will also sometimes not do it, so I floor it again and then it will do it again.

I also have just replaced this engine and I don't no how long the jeep was siting before I bought it so I don't know if the pcm has a problem, or if the pcm has the lastest flash. When I replaced different sensors the problem would happen at different rpm's when I floored it. I am lost to what the problem could be. Since every time I replace a sensor the jeep will run good then all of a sudden start having the problem again.

I am thinking maybe a bad pcm or a bad fuel filter but again I am just guessing.

Any help would be greatly appreciated.

ljhopp is offline  
Sponsored Links
Advertisement
 
post #2 of 14 Old 06-20-2010, 03:15 PM
Wrangler11
Registered User
 
Wrangler11's Avatar
2002 WJ 
 
Join Date: Feb 2006
Location: Chicago
Posts: 2,243
Maybe clogged injectors since it only seems to happen when you floor it... Stop flooring it.

2002 Grand Cherokee Limited
1994 Toyota Land Cruiser (camping offload toy)
Wrangler11 is offline  
post #3 of 14 Old 06-20-2010, 03:41 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Quote:
Originally Posted by Wrangler11 View Post
Maybe clogged injectors since it only seems to happen when you floor it... Stop flooring it.
Would that cause a p1391 check engine light to come on.
ljhopp is offline  
post #4 of 14 Old 06-20-2010, 06:04 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Here is a link to the engine.

YouTube - 99 jeep grand cherokee with p1391
ljhopp is offline  
post #5 of 14 Old 06-20-2010, 06:46 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Does anybody have an idea?
ljhopp is offline  
post #6 of 14 Old 06-20-2010, 07:27 PM
narnwv
Moderator
 
narnwv's Avatar
2000 WJ 
 
Join Date: Sep 2009
Location: Cross Lanes
Posts: 6,416
what's making the ticking noise when you're aiming at the engine bay? where is that coming from?
narnwv is offline  
post #7 of 14 Old 06-20-2010, 07:30 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Quote:
Originally Posted by narnwv View Post
what's making the ticking noise when you're aiming at the engine bay? where is that coming from?
The ac compressor is where it sounds like it coming from.

The engine I just got as a reman.
ljhopp is offline  
post #8 of 14 Old 06-20-2010, 07:51 PM
narnwv
Moderator
 
narnwv's Avatar
2000 WJ 
 
Join Date: Sep 2009
Location: Cross Lanes
Posts: 6,416
p1391 is "intermittent loss of cmp or ckp" I'd double check the connectors, make sure there's no corrosion, and follow the wires and make sure there's no kinks or sharp bends, etc.... I'd also check nearby grounds, pull them and sand off corrosion/rust.
narnwv is offline  
post #9 of 14 Old 06-20-2010, 07:59 PM
Wrangler11
Registered User
 
Wrangler11's Avatar
2002 WJ 
 
Join Date: Feb 2006
Location: Chicago
Posts: 2,243
Quote:
Originally Posted by ljhopp View Post
Would that cause a p1391 check engine light to come on.
No idea, just a guess based on what is happening.

2002 Grand Cherokee Limited
1994 Toyota Land Cruiser (camping offload toy)
Wrangler11 is offline  
post #10 of 14 Old 06-20-2010, 09:07 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Quote:
Originally Posted by narnwv View Post
p1391 is "intermittent loss of cmp or ckp" I'd double check the connectors, make sure there's no corrosion, and follow the wires and make sure there's no kinks or sharp bends, etc.... I'd also check nearby grounds, pull them and sand off corrosion/rust.
I have a haynes manual, so I have all the codes and what they mean. I am just really confused to what is causeing this. I double checked all the connectors and they look good. I think their is short somewhere in the wiring because it seems like the more I drive the jeep it seems to start having the problem soon on the rpm's. At first it wouldn't do it when in park and reving it, now it does it when in park and reving it so it seems to be getting worse. But as soon has it gets past the studder it takes off like nothing is wrong.
ljhopp is offline  
post #11 of 14 Old 06-20-2010, 09:40 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Could the map sensor be causing this problem since it controls fuel delivery and lignition timing. Sounds like good guess to.
ljhopp is offline  
post #12 of 14 Old 06-20-2010, 11:06 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Quote:
Originally Posted by narnwv View Post
p1391 is "intermittent loss of cmp or ckp" I'd double check the connectors, make sure there's no corrosion, and follow the wires and make sure there's no kinks or sharp bends, etc.... I'd also check nearby grounds, pull them and sand off corrosion/rust.
Do you know where the wires that come from the sensor's go to? What pcm harness connector are they connected to, the one on the left side or middle or the right side.

Thanks
ljhopp is offline  
post #13 of 14 Old 06-21-2010, 09:44 AM
narnwv
Moderator
 
narnwv's Avatar
2000 WJ 
 
Join Date: Sep 2009
Location: Cross Lanes
Posts: 6,416
I am unsure which connector they are. It's not going to hurt anything to pull and clean the battery terminals, but while they're disconnected--pull and inspect the PCM connectors.
narnwv is offline  
post #14 of 14 Old 06-21-2010, 09:18 PM Thread Starter
ljhopp
Registered User
1999 WJ 
 
Join Date: Jun 2010
Location: iowa
Posts: 277
Quote:
Originally Posted by narnwv View Post
I am unsure which connector they are. It's not going to hurt anything to pull and clean the battery terminals, but while they're disconnected--pull and inspect the PCM connectors.
I did all that today and still nothing I even checked all the volts and grounds at the sensors and everything checked ok. I think I have a bad pcm that is causing the problem.
ljhopp 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
Umm...I'm Confused stratons_yj ZJ Grand Cherokee Forum 17 01-22-2010 08:22 PM
How is this possible? im confused... lakailimited06 ZJ Grand Cherokee Forum 4 05-06-2008 11:27 PM
little confused 97 ZJ Steve ZJ Grand Cherokee Forum 11 02-03-2008 09:45 AM
I'm so confused! jcollins ZJ Grand Cherokee Forum 10 06-14-2007 07:01 AM
I am confused Kess ZJ Grand Cherokee Forum 3 11-06-2002 01:25 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