Fuel pressure questions - 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 > Fuel pressure questions

ZONE 4.25" combo lift for TJ available at Rockridge4wHalloween Savings to die for!Offset Tie Rod Kit From RuffStuff!

Reply
Unread 02-17-2014, 11:57 AM   #1
mylogylo
Registered User
1994 YJ Wrangler 
 
Join Date: May 2007
Location: Dillon, Colorado
Posts: 377
Fuel pressure questions

The jeep has not been running so smooth lately so I wanted to check some things out. First I checked the fuel pressure.

At the rail. When I turned the key on it popped up to 39 psi and very slowly started to go down. Dropped to about 30 after a couple of minutes.

When I started it, cold btw, it idles between 62 and 64 PSI.

Does that sound pretty normal? Everything I read says the pressure at idle should be way lower.

I also got codes 14 map sensor and 21 oxygen sensor...odd that they both popped up at the same time.

mylogylo is offline   Reply With Quote Quick reply to this message
Unread 02-17-2014, 12:07 PM   #2
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,554
No, that is very very high. You should have 31 psi idle running. You need to check and see if the return line is pinched or the issue is the regulator. Pull the return line off the fuel rail. put a hose on the fuel rail and put it into a gas can. Hook up your pressure guage and then with the guage in sight start it. If the pressure is 31 then the return line is plugged. If it is still high the regulator is bad. Clear your codes by disconnecting the battery and see what you get after you have fixed the fuel problem. The 21 is probably related to your fuel problem.
Que89YJ is offline   Reply With Quote Quick reply to this message
Unread 02-17-2014, 02:10 PM   #3
mylogylo
Registered User
1994 YJ Wrangler 
 
Join Date: May 2007
Location: Dillon, Colorado
Posts: 377
So I pulled the return line...I think...closest to the front...I'm sure it is because gas came out when running. Anyways, with the line pulled it read around 36psi at idle. I did just replaced the rubber hoses going to the tank about a month ago so I thought I'd drop it and see if they were pinched. The all look good. With the tank dropped and the return line hooked back up I still am reading a little above 60 PSI. Any suggestions? I am scratching my head. The hoses shouldn't really collapse since the return line is pressurized right?
mylogylo is offline   Reply With Quote Quick reply to this message
Unread 02-17-2014, 03:58 PM   #4
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,554
It is probably the return line hitting the bottom off the tank. Pull the line back at the tank and check it again. If it's 31 with it disconnected then post back and we can go from there.
Que89YJ is offline   Reply With Quote Quick reply to this message
Unread 02-17-2014, 04:25 PM   #5
mylogylo
Registered User
1994 YJ Wrangler 
 
Join Date: May 2007
Location: Dillon, Colorado
Posts: 377
It's 35-36PSI with the line pulled at the rail. I reattached at the rail and pulled the hose at the tank. 35-36PSI. I can blow through the line from the rail with it disconnected at the tank with ease. So I guess it has to be in the tank. Guessing I just pull the pump and trim the return tube at the bottom? Thanks for your help BTW!
mylogylo is offline   Reply With Quote Quick reply to this message
Unread 02-17-2014, 04:42 PM   #6
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,554
two inches should do it
Que89YJ is offline   Reply With Quote Quick reply to this message
Unread 02-17-2014, 05:30 PM   #7
mylogylo
Registered User
1994 YJ Wrangler 
 
Join Date: May 2007
Location: Dillon, Colorado
Posts: 377
That did the trick it seems! Wonder how long that crap has been going on LOL. Just gotta tighten her up and open a beer. Thanks again!!!!!!!
mylogylo is offline   Reply With Quote Quick reply to this message
Unread 02-17-2014, 07:39 PM   #8
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 15,554
Your welcome.
Que89YJ 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.