International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > General FSJ Tech

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-01-2009, 02:24 PM
silvercert silvercert is offline
Gear Head
 
Join Date: Feb 05, 2009
Location: Goldsboro NC
Posts: 707
Fuel Gauge

My fuel gauge is pegged. Sometimes I will see a little twinkle in its eye and it will hop a little. I have tried moving the wire around the sending unit but nothing happens there. Any thoughts?
Reply With Quote
  #2  
Old 06-01-2009, 02:26 PM
mattmopar440's Avatar
mattmopar440 mattmopar440 is offline
AMC 4 OH! 1
 
Join Date: May 17, 2007
Location: Algonquin (Chicago suburb) Illinois
Posts: 4,092
What year is you jeep make model ???
Do you have a muilt-meter ????
__________________
87' Grand Wagoneer
401/727/229, Currently:RUNNING
84 J10/20 hybrid 258/727/208 Daily Driver
80' J10 4BT/AX-15/208
74' J10 Go Grabber Green Sold
Quote:
Originally Posted by Heavy_Metal_Thunder_81
Inferior Chevy


Reply With Quote
  #3  
Old 06-01-2009, 08:12 PM
billyrb's Avatar
billyrb billyrb is offline
BJ's Off-Road
 
Join Date: Aug 15, 2001
Location: Acworth, GA 30101
Posts: 10,031
pegged usually means grounded out. Check the wire from the sending unit to the frame (probably a pink wire) and see if it's shorted / touching a bare spot. Also, when a sending unit goes south, this can sometimes read pegged.
__________________
BJ's Off-Road
ryan@bjsoffroad.com
Your source for '63-'91 FSJ Parts
Reply With Quote
  #4  
Old 06-02-2009, 06:56 AM
silvercert silvercert is offline
Gear Head
 
Join Date: Feb 05, 2009
Location: Goldsboro NC
Posts: 707
Quote:
Originally Posted by mattmopar440
What year is you jeep make model ???
Do you have a muilt-meter ????

87 Grand Wagoneer, and yes I have meter
Reply With Quote
  #5  
Old 06-02-2009, 08:45 AM
Wagoncrzy's Avatar
Wagoncrzy Wagoncrzy is offline
Gear Head
 
Join Date: Apr 23, 2006
Location: Phila.
Posts: 515
Testing for sending unit

Do an OHM test on the sending unit.
1) Fold your back seat forward and move carpet back. You should see a circular access panel in the floor on the drvrs side. Open this (4 screws) to access your sending unit. The sending unit with a full tank of gas should give you a reading around 110 OHM's-1/2 tank 55 Ohms- empty 1 OHM...

You can even remove the sender to check its operation. Through the access panel. Clean any sand, rust,or leaves off the top of the sender....(don't want that trash in your tank) Disconnect and put some screws in the fuel line and vent line to prevent anything getting into them disconnect the ground wire and guage wire.....Using a flat screw driver and hammer tap the outisde of the retaining ring counter clockwise. Remove the retaining ring. You should now habve a straight screwdriver and needle nose pliers close by. You may have to disconnect the float from the sender to get it out....gently use the screwdriver to pop the float out of the retaining clips being very careful not to drop it into the tank.

2) Check the senders ground. It is grounded with a 2 other wires on the drvrs rear frame.....The sender also uses two pigtails to connect itself to the wiring harness ...I'd clean those connections.

3) This is the one that's a little more tricky. The wire going to the guage I believe is TAN it could be shorting out... inside the wiring harness running along the frame. That being said....the wire loom runs between the frame and the gas tank. You may have to drop the tank...it isn't that difficult unless you have a full tank of gas....if so drive it around the block 2x it should be empty then

I'm still chasing my fuel sender goblin and will update this for more information as I go.

let me know if this helps. jim
__________________
Keep on Waggin!!

87 Grand Wagoneer w/Sunroof ...BJ's 2.5" Lift,Tadrack, Dana 44's, 3.31 gear ratio, Warn SS diff skid plate, 31x10.5 A/T BF Goodrich tires, SS brake lines. Rebuilt 360, Edelbrock 3731 intake, 1400 carb and Z&M HEI Dist. 260H Crane Cam. Frame sandblasted and painted w/truck bed liner.
Reply With Quote
  #6  
Old 06-02-2009, 09:46 PM
silvercert silvercert is offline
Gear Head
 
Join Date: Feb 05, 2009
Location: Goldsboro NC
Posts: 707
Quote:
Originally Posted by Wagoncrzy
Do an OHM test on the sending unit.
1) Fold your back seat forward and move carpet back. You should see a circular access panel in the floor on the drvrs side. Open this (4 screws) to access your sending unit. The sending unit with a full tank of gas should give you a reading around 110 OHM's-1/2 tank 55 Ohms- empty 1 OHM...

You can even remove the sender to check its operation. Through the access panel. Clean any sand, rust,or leaves off the top of the sender....(don't want that trash in your tank) Disconnect and put some screws in the fuel line and vent line to prevent anything getting into them disconnect the ground wire and guage wire.....Using a flat screw driver and hammer tap the outisde of the retaining ring counter clockwise. Remove the retaining ring. You should now habve a straight screwdriver and needle nose pliers close by. You may have to disconnect the float from the sender to get it out....gently use the screwdriver to pop the float out of the retaining clips being very careful not to drop it into the tank.

2) Check the senders ground. It is grounded with a 2 other wires on the drvrs rear frame.....The sender also uses two pigtails to connect itself to the wiring harness ...I'd clean those connections.

3) This is the one that's a little more tricky. The wire going to the guage I believe is TAN it could be shorting out... inside the wiring harness running along the frame. That being said....the wire loom runs between the frame and the gas tank. You may have to drop the tank...it isn't that difficult unless you have a full tank of gas....if so drive it around the block 2x it should be empty then

I'm still chasing my fuel sender goblin and will update this for more information as I go.

let me know if this helps. jim

Lots of great info thanks. I will try all of this.
Reply With Quote
  #7  
Old 06-02-2009, 11:20 PM
Langdon Langdon is offline
327 Rambler
 
Join Date: May 06, 2000
Location: Oregon
Posts: 717
Check the wiring, yes...but don't be suprised if the sending unit is wasted.
__________________
Langdon
Gone but not forgotten:
'79 Model 17 "Cherokee S" 360/TH400/BW1339/44,44/3.51

'80 Model 17 "Cherokee S" 305 Vortec FI/4L60E/241C/44,20/3.73
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 03:30 PM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
corner corner