Fuel gauge problems - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans Advertise
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 03-23-2019, 01:26 PM
Registered User
 
Join Date: Sep 2018
Posts: 31
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Fuel gauge problems

I have a sunpro fuel gauge and a bad sending unit checked it with a multimeter. My local speed shop said the ohm rating should be on the back of the fuel guage but it's not there. Does anyone know the ohm rating of a sunpro fuel guage or how to tell what my sending units ohm's are? I looked all over my sending unit and the only writing on it says made in China. So I'm not sure what my sending units ohm's are.
Thanks,
Rick

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-23-2019, 03:41 PM
rip-tide's Avatar
Magazines have “ISSUES”
 

Last journal entry: Looks good
Join Date: Mar 2017
Location: Woodstock, GA
Posts: 907
Wiki Edits: 0

Thanks: 16
Thanked 313 Times in 227 Posts
Found a part number, guessing it will be 90 ohm

http://image.fourwheeler.com/f/82238...nding-unit.jpg
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-24-2019, 09:26 PM
Registered User
 
Join Date: Sep 2018
Posts: 31
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by rip-tide View Post
Found a part number, guessing it will be 90 ohm

http://image.fourwheeler.com/f/82238...nding-unit.jpg
I found this sending unit and the image shows a chart showing empty/full resistance. So the sunpro gauge I have is aftermarket and on the chart it says most aftermarket gauges call for 240/33 ohms. Does anyone know for sure what the empty/full resistance should be on the fuel gauge sending unit with my aftermarket sunpro fuel gauge?

Thanks,
Rick
Attached Thumbnails
Click image for larger version

Name:	Screenshot_20190324-221207_1553480779926.jpg
Views:	30
Size:	62.9 KB
ID:	441659   Click image for larger version

Name:	Screenshot_20190324-221216_1553480789051.jpg
Views:	17
Size:	54.5 KB
ID:	441661  
Reply With Quote Quick reply to this message
 
  #4 (permalink)  
Old 03-25-2019, 12:48 AM
Registered User
 
Join Date: Mar 2017
Location: Phoenix,AZ
Posts: 429
Wiki Edits: 0

Thanks: 30
Thanked 111 Times in 100 Posts
Another chart: Universal Fuel Sender Questions and Troubleshooting
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-27-2019, 12:53 PM
silver74vette's Avatar
Registered User
 
Join Date: Feb 2018
Posts: 164
Wiki Edits: 0

Thanks: 36
Thanked 29 Times in 22 Posts
Your best bet is to get a couple of resistors and put them in the circuit and see what it reads. I was not able to find anything for the sunpro.

You could also just buy a new gauge, then you would know for sure.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-27-2019, 01:14 PM
Registered User
 
Join Date: Mar 2017
Location: Phoenix,AZ
Posts: 429
Wiki Edits: 0

Thanks: 30
Thanked 111 Times in 100 Posts
Quote:
Originally Posted by Raven57 View Post
I found this sending unit and the image shows a chart showing empty/full resistance. So the sunpro gauge I have is aftermarket and on the chart it says most aftermarket gauges call for 240/33 ohms. Does anyone know for sure what the empty/full resistance should be on the fuel gauge sending unit with my aftermarket sunpro fuel gauge?

Thanks,
Rick
EZ to find this will tell you: https://www.tooldiscounter.com/ItemD...hoCMxgQAvD_BwE
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-27-2019, 03:17 PM
Registered User
 
Join Date: Sep 2018
Posts: 31
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ok so I bought a new sending unit 33-240ohms and hooked it up. So now the fuel guage moves from empty to 3/4. It only goes to 3/4 full though. Before it would only go right to full and not move at all until i shut the car off. I think I might try and order the sending unit that JeffB28 just suggested. Thanks everyone I'll let you know how it goes. Also right now and when i tested the unit outside the tank I did not have the car running I just had it on auxiliary does that matter?

Thanks,
Rick
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-27-2019, 03:22 PM
AllSteel34's Avatar
Registered User
 
Join Date: Jul 2006
Location: Petaluma, California
Age: 48
Posts: 58
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If you are unable to figure out the ohm rating on your gauge or sender, consider this possible solution:

https://www.speedwaymotors.com/Speed...ule,66534.html

Give the electronics two data points: full and empty. It figures out the rest.

I've used one. It works well. Installed in about an hour and it was much easier than changing senders.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-27-2019, 07:48 PM
rip-tide's Avatar
Magazines have “ISSUES”
 

Last journal entry: Looks good
Join Date: Mar 2017
Location: Woodstock, GA
Posts: 907
Wiki Edits: 0

Thanks: 16
Thanked 313 Times in 227 Posts
Quote:
Originally Posted by Raven57 View Post
Ok so I bought a new sending unit 33-240ohms and hooked it up. So now the fuel guage moves from empty to 3/4. It only goes to 3/4 full though. Before it would only go right to full and not move at all until i shut the car off. I think I might try and order the sending unit that JeffB28 just suggested. Thanks everyone I'll let you know how it goes. Also right now and when i tested the unit outside the tank I did not have the car running I just had it on auxiliary does that matter?

Thanks,
Rick
From Jegs:
"Sunpro Fuel Cell Sending Unit" ... Universal Fuel Level Sending Unit Kit; Ohms Empty: 240; Ohms Full: 33;
So looks correct, the gauge will work as it should off the tank as long as the ring is ground to the car. Make sure you have a full 12v on the wire to the sender. Make sure the arm of the float in free floating, not jammed up against the sending unit itself. At the full level, sometimes bending is required, not unusual.

Pep

Last edited by rip-tide; 03-27-2019 at 08:05 PM.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last 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 email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Quadrajet running rich no matter what jet size is used modrummer Engine 30 10-06-2016 07:40 AM
65 impala 454 still overheating hotrodcommuter Engine 18 08-19-2016 09:39 AM
fuel gauge problems Bracewell Engine 1 10-26-2009 06:19 PM
fuel gauge problems grapro Electrical 5 03-16-2009 02:13 PM
Fuel gauge problems 1969NovaSS Electrical 5 05-05-2006 12:42 AM


All times are GMT -6. The time now is 07:36 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.